Release v0.21.2

See https://github.com/lovell/sharp-libvips/issues/12

.gitattributes

@@ -0,0 +1 @@
+src/libvips/* linguist-vendored

.gitignore

@@ -1,11 +1,15 @@
 build
 node_modules
-coverage
+/coverage
 test/bench/node_modules
 test/fixtures/output*
 test/leak/libvips.supp
-lib
+test/saliency/report.json
-include
+test/saliency/Image*
-packaging/libvips*
+test/saliency/[Uu]serData*
-packaging/*.log
+!test/saliency/userData.js
+vendor
+.gitattributes
 .DS_Store
+.nyc_output
+package-lock.json

.jshintignore

@@ -1,3 +0,0 @@
-node_modules
-test/bench/node_modules
-coverage

.jshintrc

@@ -1,12 +0,0 @@
-{
-  "strict": true,
-  "node": true,
-  "maxparams": 4,
-  "maxcomplexity": 13,
-  "globals": {
-    "beforeEach": true,
-    "afterEach": true,
-    "describe": true,
-    "it": true
-  }
-}

.npmignore

@@ -2,15 +2,14 @@ build
 node_modules
 coverage
 .editorconfig
-.jshintignore
+.gitattributes
-.jshintrc
 .gitignore
 test
 .travis.yml
 appveyor.yml
-circle.yml
 mkdocs.yml
-lib
+docs/css/
-include
+vendor
-packaging
+.prebuildrc
-preinstall.sh
+.nyc_output
+CONTRIBUTING.md

.prebuildrc

@@ -0,0 +1,4 @@
+{
+  "include-regex": "(sharp\\.node|libvips-cpp\\.dll)",
+  "strip": true
+}

.travis.yml

@@ -1,22 +1,79 @@
-language: node_js
+matrix:
-node_js:
+  include:
-  - "0.10"
+    - name: "Linux (glibc) - Node 6"
-  - "0.12"
+      os: linux
-  - "4"
+      dist: trusty
-  - "5"
+      sudo: false
-os:
+      language: node_js
-  - linux
+      node_js: "6"
-  - osx
+    - name: "Linux (glibc) - Node 8"
-sudo: false
+      os: linux
-addons:
+      dist: trusty
-  apt:
+      sudo: false
-    sources:
+      language: node_js
-    - ubuntu-toolchain-r-test
+      node_js: "8"
-    packages:
+    - name: "Linux (glibc) - Node 10"
-    - g++-4.8
+      os: linux
-osx_image: xcode7.3
+      dist: trusty
-before_install:
+      sudo: false
-  - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then export CXX=g++-4.8; fi
+      language: node_js
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew install homebrew/science/vips; fi
+      node_js: "10"
-after_success:
+      after_success:
-  - cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js
+        - npm install coveralls
+        - cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js
+    - name: "Linux (glibc) - Node 11"
+      os: linux
+      dist: trusty
+      sudo: false
+      language: node_js
+      node_js: "11"
+    - name: "Linux (musl) - Node 8"
+      os: linux
+      dist: trusty
+      sudo: true
+      language: minimal
+      before_install:
+        - sudo docker run -dit --name sharp --env CI --env PREBUILD_TOKEN --volume "${PWD}:/mnt/sharp" --workdir /mnt/sharp node:8-alpine
+        - sudo docker exec sharp apk add build-base git python2 --update-cache
+      install: sudo docker exec sharp sh -c "npm install --unsafe-perm"
+      script: sudo docker exec sharp sh -c "npm test"
+    - name: "Linux (musl) - Node 10"
+      os: linux
+      dist: trusty
+      sudo: true
+      language: minimal
+      before_install:
+        - sudo docker run -dit --name sharp --env CI --env PREBUILD_TOKEN --volume "${PWD}:/mnt/sharp" --workdir /mnt/sharp node:10-alpine
+        - sudo docker exec sharp apk add build-base git python2 --update-cache
+      install: sudo docker exec sharp sh -c "npm install --unsafe-perm"
+      script: sudo docker exec sharp sh -c "npm test"
+    - name: "Linux (musl) - Node 11"
+      os: linux
+      dist: trusty
+      sudo: true
+      language: minimal
+      before_install:
+        - sudo docker run -dit --name sharp --env CI --env PREBUILD_TOKEN --volume "${PWD}:/mnt/sharp" --workdir /mnt/sharp node:11-alpine
+        - sudo docker exec sharp apk add build-base git python2 --update-cache
+      install: sudo docker exec sharp sh -c "npm install --unsafe-perm"
+      script: sudo docker exec sharp sh -c "npm test"
+    - name: "OS X - Node 6"
+      os: osx
+      osx_image: xcode9.2
+      language: node_js
+      node_js: "6"
+    - name: "OS X - Node 8"
+      os: osx
+      osx_image: xcode9.2
+      language: node_js
+      node_js: "8"
+    - name: "OS X - Node 10"
+      os: osx
+      osx_image: xcode9.2
+      language: node_js
+      node_js: "10"
+    - name: "OS X - Node 11"
+      os: osx
+      osx_image: xcode9.2
+      language: node_js
+      node_js: "11"

CONTRIBUTING.md

@@ -14,7 +14,7 @@ New bugs are assigned a `triage` label whilst under investigation.
 
 If a [similar request](https://github.com/lovell/sharp/labels/enhancement) exists, it's probably fastest to add a comment to it about your requirement.
 
-Implementation is usually straightforward if _libvips_ [already supports](http://www.vips.ecs.soton.ac.uk/supported/current/doc/html/libvips/ch03.html) the feature you need.
+Implementation is usually straightforward if _libvips_ [already supports](https://libvips.github.io/libvips/API/current/) the feature you need.
 
 ## Submit a Pull Request to fix a bug
 
@@ -41,9 +41,8 @@ Any change that modifies the existing public API should be added to the relevant
 
 | Release | WIP branch |
 | ------: | :--------- |
-| v0.15.0 | outfit     |
+| v0.21.0 | teeth      |
-| v0.16.0 | pencil     |
+| v0.22.0 | uptake     |
-| v0.17.0 | quill      |
 
 Please squash your changes into a single commit using a command like `git rebase -i upstream/<wip-branch>`.
 
@@ -63,6 +62,17 @@ A method to be removed should be deprecated in the next major version then remov
 
 By way of example, the [bilinearInterpolation method](https://github.com/lovell/sharp/blob/v0.6.0/index.js#L155) present in v0.5.0 was deprecated in v0.6.0 and removed in v0.7.0.
 
+## Documentation
+
+The public API is documented with [JSDoc](http://usejsdoc.org/) annotated comments.
+
+These can be converted to Markdown by running:
+```sh
+npm run docs
+```
+
+Please include documentation updates in any Pull Request that modifies the public API.
+
 ## Run the tests
 
 ### Functional tests and static code analysis
@@ -79,15 +89,11 @@ Requires [Valgrind](http://valgrind.org/).
 npm run test-leak
 ```
 
-### Packaging tests
-
-Tests the installation on a number of Linux-based operating systems.
-Requires docker.
-
-```sh
-npm run test-packaging
-```
-
 ## Finally
 
-Please feel free to ask any questions via a [new issue](https://github.com/lovell/sharp/issues/new) or contact me by [e-mail](https://github.com/lovell/sharp/blob/master/package.json#L4).
+Please feel free to ask any questions via a
+[new issue](https://github.com/lovell/sharp/issues/new).
+
+If you're unable to post details publicly, please
+[e-mail](https://github.com/lovell/sharp/blob/master/package.json#L4)
+for private, paid consulting.

README.md

@@ -1,47 +1,93 @@
 # sharp
 
+<img src="docs/image/sharp-logo.svg" width="160" height="160" alt="sharp logo" align="right">
+
+```sh
+npm install sharp
+```
+
+```sh
+yarn add sharp
+```
+
 The typical use case for this high speed Node.js module
-is to convert large images of many formats to
+is to convert large images in common formats to
 smaller, web-friendly JPEG, PNG and WebP images of varying dimensions.
 
-Resizing an image is typically 4x faster than using the
+Resizing an image is typically 4x-5x faster than using the
 quickest ImageMagick and GraphicsMagick settings.
 
 Colour spaces, embedded ICC profiles and alpha transparency channels are all handled correctly.
-Bicubic interpolation with Lanczos anti-alias filtering ensures quality is not sacrificed for speed.
+Lanczos resampling ensures quality is not sacrificed for speed.
 
 As well as image resizing, operations such as
 rotation, extraction, compositing and gamma correction are available.
 
-Most Windows (x64), Linux and ARMv6+ systems do not require
+Most modern 64-bit OS X, Windows and Linux systems running
-the installation of any external runtime dependencies.
+Node versions 6, 8, 10 and 11
+do not require any additional install or runtime dependencies.
 
-Use with OS X is as simple as running `brew install homebrew/science/vips`
+## Examples
-to install the libvips dependency.
 
-[![Test Coverage](https://coveralls.io/repos/lovell/sharp/badge.png?branch=master)](https://coveralls.io/r/lovell/sharp?branch=master)
+```javascript
+const sharp = require('sharp');
+```
+
+```javascript
+sharp(inputBuffer)
+  .resize(320, 240)
+  .toFile('output.webp', (err, info) => ... );
+  // A Promises/A+ promise is returned when callback is not provided.
+```
+
+```javascript
+sharp('input.jpg')
+  .rotate()
+  .resize(200)
+  .toBuffer()
+  .then( data => ... )
+  .catch( err => ... );
+```
+
+```javascript
+const roundedCorners = Buffer.from(
+  '<svg><rect x="0" y="0" width="200" height="200" rx="50" ry="50"/></svg>'
+);
+
+const roundedCornerResizer =
+  sharp()
+    .resize(200, 200)
+    .overlayWith(roundedCorners, { cutout: true })
+    .png();
+
+readableStream
+  .pipe(roundedCornerResizer)
+  .pipe(writableStream);
+```
+
+[![Test Coverage](https://coveralls.io/repos/lovell/sharp/badge.svg?branch=master)](https://coveralls.io/r/lovell/sharp?branch=master)
 
 ### Documentation
 
-Visit [sharp.dimens.io](http://sharp.dimens.io/) for complete
+Visit [sharp.pixelplumbing.com](https://sharp.pixelplumbing.com/) for complete
-[installation instructions](http://sharp.dimens.io/page/install),
+[installation instructions](https://sharp.pixelplumbing.com/page/install),
-[API documentation](http://sharp.dimens.io/page/api),
+[API documentation](https://sharp.pixelplumbing.com/page/api),
-[benchmark tests](http://sharp.dimens.io/page/performance) and
+[benchmark tests](https://sharp.pixelplumbing.com/page/performance) and
-[changelog](http://sharp.dimens.io/page/changelog).
+[changelog](https://sharp.pixelplumbing.com/page/changelog).
 
 ### Contributing
 
 A [guide for contributors](https://github.com/lovell/sharp/blob/master/CONTRIBUTING.md)
 covers reporting bugs, requesting features and submitting code changes.
 
-### Licence
+### Licensing
 
-Copyright 2013, 2014, 2015, 2016 Lovell Fuller and contributors.
+Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
-[http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0.html)
+[https://www.apache.org/licenses/LICENSE-2.0](https://www.apache.org/licenses/LICENSE-2.0)
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,

appveyor.yml

@@ -3,13 +3,14 @@ version: "{build}"
 build: off
 platform: x64
 environment:
-  VIPS_WARNING: 0
   matrix:
-  - nodejs_version: "0.12"
+  - nodejs_version: "6"
-  - nodejs_version: "4"
+  - nodejs_version: "8"
-  - nodejs_version: "5"
+  - nodejs_version: "10"
+  - nodejs_version: "11"
 install:
   - ps: Install-Product node $env:nodejs_version x64
+  - npm install -g npm@5
   - npm install
 test_script:
-  - npm run-script test-win
+  - npm test

binding.gyp

@@ -5,11 +5,9 @@
       ['OS == "win"', {
         # Build libvips C++ binding for Windows due to MSVC std library ABI changes
         'type': 'shared_library',
-        'variables': {
-          'download_vips': '<!(node -e "require(\'./binding\').download_vips()")'
-        },
         'defines': [
-          'VIPS_CPLUSPLUS_EXPORTS'
+          'VIPS_CPLUSPLUS_EXPORTS',
+          '_ALLOW_KEYWORD_MACROS'
         ],
         'sources': [
           'src/libvips/cplusplus/VError.cpp',
@@ -17,14 +15,14 @@
           'src/libvips/cplusplus/VImage.cpp'
         ],
         'include_dirs': [
-          '<(module_root_dir)/include',
+          'vendor/include',
-          '<(module_root_dir)/include/glib-2.0',
+          'vendor/include/glib-2.0',
-          '<(module_root_dir)/lib/glib-2.0/include'
+          'vendor/lib/glib-2.0/include'
         ],
         'libraries': [
-          '<(module_root_dir)/lib/libvips.lib',
+          '../vendor/lib/libvips.lib',
-          '<(module_root_dir)/lib/libglib-2.0.lib',
+          '../vendor/lib/libglib-2.0.lib',
-          '<(module_root_dir)/lib/libgobject-2.0.lib'
+          '../vendor/lib/libgobject-2.0.lib'
         ],
         'configurations': {
           'Release': {
@@ -48,56 +46,32 @@
     'dependencies': [
       'libvips-cpp'
     ],
-    # Nested variables "pattern" borrowed from http://src.chromium.org/viewvc/chrome/trunk/src/build/common.gypi
     'variables': {
-      'variables': {
-        'variables': {
-          'conditions': [
-            ['OS != "win"', {
-              # Build the PKG_CONFIG_PATH environment variable with all possible combinations
-              'pkg_config_path': '<!(which brew >/dev/null 2>&1 && eval $(brew --env) && echo $PKG_CONFIG_LIBDIR || true):$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig:/usr/lib/pkgconfig'
-            }, {
-              'pkg_config_path': ''
-            }]
-          ],
-        },
-        'conditions': [
-          ['OS != "win"', {
-            # Which version, if any, of libvips is available globally via pkg-config?
-            'global_vips_version': '<!(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --modversion vips-cpp 2>/dev/null || true)'
-          }, {
-            'global_vips_version': ''
-          }]
-        ],
-        'pkg_config_path%': '<(pkg_config_path)'
-      },
-      'pkg_config_path%': '<(pkg_config_path)',
       'runtime_link%': 'shared',
       'conditions': [
         ['OS != "win"', {
-          # Does the globally available version of libvips, if any, meet the minimum version requirement?
+          'pkg_config_path': '<!(node -e "console.log(require(\'./lib/libvips\').pkgConfigPath())")',
-          'use_global_vips': '<!(GLOBAL_VIPS_VERSION="<(global_vips_version)" node -e "require(\'./binding\').use_global_vips()")'
+          'use_global_libvips': '<!(node -e "console.log(Boolean(require(\'./lib/libvips\').useGlobalLibvips()).toString())")'
         }, {
-          'use_global_vips': ''
+          'pkg_config_path': '',
+          'use_global_libvips': ''
         }]
       ]
     },
     'sources': [
       'src/common.cc',
       'src/metadata.cc',
+      'src/stats.cc',
       'src/operations.cc',
       'src/pipeline.cc',
       'src/sharp.cc',
       'src/utilities.cc'
     ],
-    'defines': [
-      '_GLIBCXX_USE_CXX11_ABI=0'
-    ],
     'include_dirs': [
       '<!(node -e "require(\'nan\')")'
     ],
     'conditions': [
-      ['use_global_vips == "true"', {
+      ['use_global_libvips == "true"', {
         # Use pkg-config for include and lib
         'include_dirs': ['<!@(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --cflags-only-I vips-cpp vips glib-2.0 | sed s\/-I//g)'],
         'conditions': [
@@ -105,52 +79,85 @@
             'libraries': ['<!@(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --libs --static vips-cpp)']
           }, {
             'libraries': ['<!@(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --libs vips-cpp)']
+          }],
+          ['OS == "linux"', {
+            'defines': [
+              # Inspect libvips-cpp.so to determine which C++11 ABI version was used and set _GLIBCXX_USE_CXX11_ABI accordingly. This is quite horrible.
+              '_GLIBCXX_USE_CXX11_ABI=<!(if readelf -Ws "$(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --variable libdir vips-cpp)/libvips-cpp.so" | c++filt | grep -qF __cxx11;then echo "1";else echo "0";fi)'
+            ]
           }]
         ]
       }, {
-        # Attempt to download pre-built libvips and install locally within node_modules
+        # Use pre-built libvips stored locally within node_modules
         'include_dirs': [
-          '<(module_root_dir)/include',
+          'vendor/include',
-          '<(module_root_dir)/include/glib-2.0',
+          'vendor/include/glib-2.0',
-          '<(module_root_dir)/lib/glib-2.0/include'
+          'vendor/lib/glib-2.0/include'
         ],
         'conditions': [
           ['OS == "win"', {
+            'defines': [
+              '_ALLOW_KEYWORD_MACROS'
+            ],
             'libraries': [
-              '<(module_root_dir)/lib/libvips.lib',
+              '../vendor/lib/libvips.lib',
-              '<(module_root_dir)/lib/libglib-2.0.lib',
+              '../vendor/lib/libglib-2.0.lib',
-              '<(module_root_dir)/lib/libgobject-2.0.lib'
+              '../vendor/lib/libgobject-2.0.lib'
+            ]
+          }],
+          ['OS == "mac"', {
+            'libraries': [
+              '../vendor/lib/libvips-cpp.42.dylib',
+              '../vendor/lib/libvips.42.dylib',
+              '../vendor/lib/libglib-2.0.0.dylib',
+              '../vendor/lib/libgobject-2.0.0.dylib',
+              # Ensure runtime linking is relative to sharp.node
+              '-rpath \'@loader_path/../../vendor/lib\''
             ]
           }],
           ['OS == "linux"', {
-            'variables': {
+            'defines': [
-              'download_vips': '<!(LDD_VERSION="<!(ldd --version 2>&1 || true)" node -e "require(\'./binding\').download_vips()")'
+              '_GLIBCXX_USE_CXX11_ABI=0'
-            },
+            ],
             'libraries': [
-              '<(module_root_dir)/lib/libvips-cpp.so',
+              '../vendor/lib/libvips-cpp.so',
-              '<(module_root_dir)/lib/libvips.so',
+              '../vendor/lib/libvips.so',
-              '<(module_root_dir)/lib/libglib-2.0.so',
+              '../vendor/lib/libglib-2.0.so',
-              '<(module_root_dir)/lib/libgobject-2.0.so',
+              '../vendor/lib/libgobject-2.0.so',
               # Dependencies of dependencies, included for openSUSE support
-              '<(module_root_dir)/lib/libGraphicsMagick.so',
+              '../vendor/lib/libcairo.so',
-              '<(module_root_dir)/lib/libGraphicsMagickWand.so',
+              '../vendor/lib/libcroco-0.6.so',
-              '<(module_root_dir)/lib/libexif.so',
+              '../vendor/lib/libexif.so',
-              '<(module_root_dir)/lib/libgio-2.0.so',
+              '../vendor/lib/libexpat.so',
-              '<(module_root_dir)/lib/libgmodule-2.0.so',
+              '../vendor/lib/libffi.so',
-              '<(module_root_dir)/lib/libgsf-1.so',
+              '../vendor/lib/libfontconfig.so',
-              '<(module_root_dir)/lib/libjpeg.so',
+              '../vendor/lib/libfreetype.so',
-              '<(module_root_dir)/lib/libpng.so',
+              '../vendor/lib/libfribidi.so',
-              '<(module_root_dir)/lib/libtiff.so',
+              '../vendor/lib/libgdk_pixbuf-2.0.so',
-              '<(module_root_dir)/lib/libwebp.so',
+              '../vendor/lib/libgif.so',
-              '<(module_root_dir)/lib/libz.so',
+              '../vendor/lib/libgio-2.0.so',
-              '<(module_root_dir)/lib/libffi.so',
+              '../vendor/lib/libgmodule-2.0.so',
-              '<(module_root_dir)/lib/libgthread-2.0.so',
+              '../vendor/lib/libgsf-1.so',
-              '<(module_root_dir)/lib/liblcms2.so',
+              '../vendor/lib/libgthread-2.0.so',
-              '<(module_root_dir)/lib/libpng16.so',
+              '../vendor/lib/libharfbuzz.so',
-              '<(module_root_dir)/lib/libxml2.so',
+              '../vendor/lib/libharfbuzz-subset.so.0',
-              '<(module_root_dir)/lib/liborc-0.4.so',
+              '../vendor/lib/libjpeg.so',
+              '../vendor/lib/liblcms2.so',
+              '../vendor/lib/liborc-0.4.so',
+              '../vendor/lib/libpango-1.0.so',
+              '../vendor/lib/libpangocairo-1.0.so',
+              '../vendor/lib/libpangoft2-1.0.so',
+              '../vendor/lib/libpixman-1.so',
+              '../vendor/lib/libpng.so',
+              '../vendor/lib/librsvg-2.so',
+              '../vendor/lib/libtiff.so',
+              '../vendor/lib/libwebp.so',
+              '../vendor/lib/libwebpdemux.so',
+              '../vendor/lib/libwebpmux.so',
+              '../vendor/lib/libxml2.so',
+              '../vendor/lib/libz.so',
               # Ensure runtime linking is relative to sharp.node
-              '-Wl,-rpath=\'$${ORIGIN}/../../lib\''
+              '-Wl,--disable-new-dtags -Wl,-rpath=\'$${ORIGIN}/../../vendor/lib\''
             ]
           }]
         ]
@@ -176,69 +183,25 @@
     },
     'configurations': {
       'Release': {
+        'cflags_cc': [
+          '-Wno-cast-function-type',
+          '-Wno-deprecated-declarations'
+        ],
+        'xcode_settings': {
+          'OTHER_CPLUSPLUSFLAGS': [
+            '-Wno-deprecated-declarations'
+          ]
+        },
         'msvs_settings': {
           'VCCLCompilerTool': {
             'ExceptionHandling': 1
           }
         },
         'msvs_disabled_warnings': [
-          4275
+          4275,
+          4996
         ]
       }
     },
-  }, {
-    'target_name': 'win_copy_dlls',
-    'type': 'none',
-    'dependencies': [
-      'sharp'
-    ],
-    'conditions': [
-      ['OS == "win"', {
-        # Windows lacks support for rpath
-        'copies': [{
-          'destination': '<(module_root_dir)/build/Release',
-          'files': [
-            '<(module_root_dir)/lib/GNU.Gettext.dll',
-            '<(module_root_dir)/lib/libMagickCore-6.Q16-2.dll',
-            '<(module_root_dir)/lib/libMagickWand-6.Q16-2.dll',
-            '<(module_root_dir)/lib/libasprintf-0.dll',
-            '<(module_root_dir)/lib/libcairo-2.dll',
-            '<(module_root_dir)/lib/libcairo-gobject-2.dll',
-            '<(module_root_dir)/lib/libcairo-script-interpreter-2.dll',
-            '<(module_root_dir)/lib/libexif-12.dll',
-            '<(module_root_dir)/lib/libexpat-1.dll',
-            '<(module_root_dir)/lib/libffi-6.dll',
-            '<(module_root_dir)/lib/libfftw3-3.dll',
-            '<(module_root_dir)/lib/libfontconfig-1.dll',
-            '<(module_root_dir)/lib/libfreetype-6.dll',
-            '<(module_root_dir)/lib/libgcc_s_seh-1.dll',
-            '<(module_root_dir)/lib/libgdk_pixbuf-2.0-0.dll',
-            '<(module_root_dir)/lib/libgio-2.0-0.dll',
-            '<(module_root_dir)/lib/libglib-2.0-0.dll',
-            '<(module_root_dir)/lib/libgmodule-2.0-0.dll',
-            '<(module_root_dir)/lib/libgobject-2.0-0.dll',
-            '<(module_root_dir)/lib/libgsf-1-114.dll',
-            '<(module_root_dir)/lib/libgthread-2.0-0.dll',
-            '<(module_root_dir)/lib/libintl-8.dll',
-            '<(module_root_dir)/lib/libjpeg-62.dll',
-            '<(module_root_dir)/lib/liblcms2-2.dll',
-            '<(module_root_dir)/lib/libopenjp2.dll',
-            '<(module_root_dir)/lib/libopenslide-0.dll',
-            '<(module_root_dir)/lib/libpango-1.0-0.dll',
-            '<(module_root_dir)/lib/libpangocairo-1.0-0.dll',
-            '<(module_root_dir)/lib/libpangowin32-1.0-0.dll',
-            '<(module_root_dir)/lib/libpixman-1-0.dll',
-            '<(module_root_dir)/lib/libpng16-16.dll',
-            '<(module_root_dir)/lib/libquadmath-0.dll',
-            '<(module_root_dir)/lib/libsqlite3-0.dll',
-            '<(module_root_dir)/lib/libssp-0.dll',
-            '<(module_root_dir)/lib/libtiff-5.dll',
-            '<(module_root_dir)/lib/libvips-42.dll',
-            '<(module_root_dir)/lib/libxml2-2.dll',
-            '<(module_root_dir)/lib/zlib1.dll'
-          ]
-        }]
-      }]
-    ]
   }]
 }

binding.js

@@ -1,134 +0,0 @@
-'use strict';
-
-var fs = require('fs');
-var path = require('path');
-var zlib = require('zlib');
-
-var semver = require('semver');
-var request = require('request');
-var tar = require('tar');
-
-var tmp = require('os').tmpdir();
-
-var distBaseUrl = 'https://dl.bintray.com/lovell/sharp/';
-
-// Use NPM-provided environment variable where available, falling back to require-based method for Electron
-var minimumLibvipsVersion = process.env.npm_package_config_libvips || require('./package.json').config.libvips;
-
-var vipsHeaderPath = path.join(__dirname, 'include', 'vips', 'vips.h');
-
-// -- Helpers
-
-// Does this file exist?
-var isFile = function(file) {
-  var exists = false;
-  try {
-    exists = fs.statSync(file).isFile();
-  } catch (err) {}
-  return exists;
-};
-
-var unpack = function(tarPath, done) {
-  var extractor = tar.Extract({
-    path: __dirname
-  });
-  extractor.on('error', error);
-  extractor.on('end', function() {
-    if (!isFile(vipsHeaderPath)) {
-      error('Could not unpack ' + tarPath);
-    }
-    if (typeof done === 'function') {
-      done();
-    }
-  });
-  fs.createReadStream(tarPath).on('error', error)
-    .pipe(zlib.Unzip())
-    .pipe(extractor);
-};
-
-// Error
-var error = function(msg) {
-  if (msg instanceof Error) {
-    msg = msg.message;
-  }
-  process.stderr.write('ERROR: ' + msg + '\n');
-  process.exit(1);
-};
-
-// -- Binary downloaders
-
-module.exports.download_vips = function() {
-  // Has vips been installed locally?
-  if (!isFile(vipsHeaderPath)) {
-    // Ensure Intel 64-bit or ARM
-    if (process.arch === 'ia32') {
-      error('Intel Architecture 32-bit systems require manual installation - please see http://sharp.dimens.io/en/stable/install/');
-    }
-    // Ensure glibc >= 2.15
-    var lddVersion = process.env.LDD_VERSION;
-    if (lddVersion) {
-      if (/(glibc|gnu libc)/i.test(lddVersion)) {
-        var glibcVersion = lddVersion ? lddVersion.split(/\n/)[0].split(' ').slice(-1)[0].trim() : '';
-        if (glibcVersion && semver.lt(glibcVersion + '.0', '2.13.0')) {
-          error('glibc version ' + glibcVersion + ' requires manual installation - please see http://sharp.dimens.io/en/stable/install/');
-        }
-      } else {
-        error(lddVersion.split(/\n/)[0] + ' requires manual installation - please see http://sharp.dimens.io/en/stable/install/');
-      }
-    }
-    // Arch/platform-specific .tar.gz
-    var platform = (process.arch === 'arm') ? 'arm' : process.platform.substr(0, 3);
-    var tarFilename = ['libvips', minimumLibvipsVersion, platform].join('-') + '.tar.gz';
-    var tarPath = path.join(__dirname, 'packaging', tarFilename);
-    if (isFile(tarPath)) {
-      unpack(tarPath);
-    } else {
-      // Download to per-process temporary file
-      tarPath = path.join(tmp, process.pid + '-' + tarFilename);
-      var tmpFile = fs.createWriteStream(tarPath).on('finish', function() {
-        unpack(tarPath, function() {
-          // Attempt to remove temporary file
-          try {
-            fs.unlinkSync(tarPath);
-          } catch (err) {}
-        });
-      });
-      var options = {
-        url: distBaseUrl + tarFilename
-      };
-      if (process.env.npm_config_https_proxy) {
-        // Use the NPM-configured HTTPS proxy
-        options.proxy = process.env.npm_config_https_proxy;
-      }
-      request(options).on('response', function(response) {
-        if (response.statusCode !== 200) {
-          error(distBaseUrl + tarFilename + ' status code ' + response.statusCode);
-        }
-      }).on('error', function(err) {
-        error('Download from ' + distBaseUrl + tarFilename + ' failed: ' + err.message);
-      }).pipe(tmpFile);
-    }
-  }
-};
-
-module.exports.use_global_vips = function() {
-  var useGlobalVips = false;
-  var globalVipsVersion = process.env.GLOBAL_VIPS_VERSION;
-  if (globalVipsVersion) {
-    useGlobalVips = semver.gte(
-      globalVipsVersion,
-      minimumLibvipsVersion
-    );
-  }
-  if (process.platform === 'darwin' && !useGlobalVips) {
-    if (globalVipsVersion) {
-      error(
-        'Found libvips ' + globalVipsVersion + ' but require ' + minimumLibvipsVersion +
-        '\nPlease upgrade libvips by running: brew update && brew upgrade'
-      );
-    } else {
-      error('Please install libvips by running: brew install homebrew/science/vips --with-webp --with-graphicsmagick');
-    }
-  }
-  process.stdout.write(useGlobalVips ? 'true' : 'false');
-};

circle.yml

@@ -1,6 +0,0 @@
-machine:
-  services:
-    - docker
-test:
-  override:
-    - ./packaging/test.sh

docs/api-channel.md

@@ -0,0 +1,115 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## removeAlpha
+
+Remove alpha channel, if any. This is a no-op if the image does not have an alpha channel.
+
+### Examples
+
+```javascript
+sharp('rgba.png')
+  .removeAlpha()
+  .toFile('rgb.png', function(err, info) {
+    // rgb.png is a 3 channel image without an alpha channel
+  });
+```
+
+Returns **Sharp** 
+
+## ensureAlpha
+
+Ensure alpha channel, if missing. The added alpha channel will be fully opaque. This is a no-op if the image already has an alpha channel.
+
+### Examples
+
+```javascript
+sharp('rgb.jpg')
+  .ensureAlpha()
+  .toFile('rgba.png', function(err, info) {
+    // rgba.png is a 4 channel image with a fully opaque alpha channel
+  });
+```
+
+Returns **Sharp** 
+
+## extractChannel
+
+Extract a single channel from a multi-channel image.
+
+### Parameters
+
+-   `channel` **([Number][1] \| [String][2])** zero-indexed band number to extract, or `red`, `green` or `blue` as alternative to `0`, `1` or `2` respectively.
+
+### Examples
+
+```javascript
+sharp(input)
+  .extractChannel('green')
+  .toFile('input_green.jpg', function(err, info) {
+    // info.channels === 1
+    // input_green.jpg contains the green channel of the input image
+   });
+```
+
+-   Throws **[Error][3]** Invalid channel
+
+Returns **Sharp** 
+
+## joinChannel
+
+Join one or more channels to the image.
+The meaning of the added channels depends on the output colourspace, set with `toColourspace()`.
+By default the output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+Channel ordering follows vips convention:
+
+-   sRGB: 0: Red, 1: Green, 2: Blue, 3: Alpha.
+-   CMYK: 0: Magenta, 1: Cyan, 2: Yellow, 3: Black, 4: Alpha.
+
+Buffers may be any of the image formats supported by sharp: JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data.
+For raw pixel input, the `options` object should contain a `raw` attribute, which follows the format of the attribute of the same name in the `sharp()` constructor.
+
+### Parameters
+
+-   `images` **([Array][4]&lt;([String][2] \| [Buffer][5])> | [String][2] \| [Buffer][5])** one or more images (file paths, Buffers).
+-   `options` **[Object][6]** image options, see `sharp()` constructor.
+
+
+-   Throws **[Error][3]** Invalid parameters
+
+Returns **Sharp** 
+
+## bandbool
+
+Perform a bitwise boolean operation on all input image channels (bands) to produce a single channel output image.
+
+### Parameters
+
+-   `boolOp` **[String][2]** one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+
+### Examples
+
+```javascript
+sharp('3-channel-rgb-input.png')
+  .bandbool(sharp.bool.and)
+  .toFile('1-channel-output.png', function (err, info) {
+    // The output will be a single channel image where each pixel `P = R & G & B`.
+    // If `I(1,1) = [247, 170, 14] = [0b11110111, 0b10101010, 0b00001111]`
+    // then `O(1,1) = 0b11110111 & 0b10101010 & 0b00001111 = 0b00000010 = 2`.
+  });
+```
+
+-   Throws **[Error][3]** Invalid parameters
+
+Returns **Sharp** 
+
+[1]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+
+[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+
+[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array
+
+[5]: https://nodejs.org/api/buffer.html
+
+[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object

docs/api-colour.md

@@ -0,0 +1,79 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## tint
+
+Tint the image using the provided chroma while preserving the image luminance.
+An alpha channel may be present and will be unchanged by the operation.
+
+### Parameters
+
+-   `rgb` **([String][1] \| [Object][2])** parsed by the [color][3] module to extract chroma values.
+
+
+-   Throws **[Error][4]** Invalid parameter
+
+Returns **Sharp** 
+
+## greyscale
+
+Convert to 8-bit greyscale; 256 shades of grey.
+This is a linear operation. If the input image is in a non-linear colour space such as sRGB, use `gamma()` with `greyscale()` for the best results.
+By default the output image will be web-friendly sRGB and contain three (identical) color channels.
+This may be overridden by other sharp operations such as `toColourspace('b-w')`,
+which will produce an output image containing one color channel.
+An alpha channel may be present, and will be unchanged by the operation.
+
+### Parameters
+
+-   `greyscale` **[Boolean][5]**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## grayscale
+
+Alternative spelling of `greyscale`.
+
+### Parameters
+
+-   `grayscale` **[Boolean][5]**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## toColourspace
+
+Set the output colourspace.
+By default output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+
+### Parameters
+
+-   `colourspace` **[String][1]?** output colourspace e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...][6]
+
+
+-   Throws **[Error][4]** Invalid parameters
+
+Returns **Sharp** 
+
+## toColorspace
+
+Alternative spelling of `toColourspace`.
+
+### Parameters
+
+-   `colorspace` **[String][1]?** output colorspace.
+
+
+-   Throws **[Error][4]** Invalid parameters
+
+Returns **Sharp** 
+
+[1]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+
+[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[3]: https://www.npmjs.org/package/color
+
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[6]: https://github.com/libvips/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568

docs/api-composite.md

@@ -0,0 +1,67 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## overlayWith
+
+Overlay (composite) an image over the processed (resized, extracted etc.) image.
+
+The overlay image must be the same size or smaller than the processed image.
+If both `top` and `left` options are provided, they take precedence over `gravity`.
+
+If the overlay image contains an alpha channel then composition with premultiplication will occur.
+
+### Parameters
+
+-   `overlay` **([Buffer][1] \| [String][2])** Buffer containing image data or String containing the path to an image file.
+-   `options` **[Object][3]?** 
+    -   `options.gravity` **[String][2]** gravity at which to place the overlay. (optional, default `'centre'`)
+    -   `options.top` **[Number][4]?** the pixel offset from the top edge.
+    -   `options.left` **[Number][4]?** the pixel offset from the left edge.
+    -   `options.tile` **[Boolean][5]** set to true to repeat the overlay image across the entire image with the given `gravity`. (optional, default `false`)
+    -   `options.cutout` **[Boolean][5]** set to true to apply only the alpha channel of the overlay image to the input image, giving the appearance of one image being cut out of another. (optional, default `false`)
+    -   `options.density` **[Number][4]** number representing the DPI for vector overlay image. (optional, default `72`)
+    -   `options.raw` **[Object][3]?** describes overlay when using raw pixel data.
+        -   `options.raw.width` **[Number][4]?** 
+        -   `options.raw.height` **[Number][4]?** 
+        -   `options.raw.channels` **[Number][4]?** 
+    -   `options.create` **[Object][3]?** describes a blank overlay to be created.
+        -   `options.create.width` **[Number][4]?** 
+        -   `options.create.height` **[Number][4]?** 
+        -   `options.create.channels` **[Number][4]?** 3-4
+        -   `options.create.background` **([String][2] \| [Object][3])?** parsed by the [color][6] module to extract values for red, green, blue and alpha.
+
+### Examples
+
+```javascript
+sharp('input.png')
+  .rotate(180)
+  .resize(300)
+  .flatten( { background: '#ff6600' } )
+  .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
+  .sharpen()
+  .withMetadata()
+  .webp( { quality: 90 } )
+  .toBuffer()
+  .then(function(outputBuffer) {
+    // outputBuffer contains upside down, 300px wide, alpha channel flattened
+    // onto orange background, composited with overlay.png with SE gravity,
+    // sharpened, with metadata, 90% quality WebP image data. Phew!
+  });
+```
+
+-   Throws **[Error][7]** Invalid parameters
+
+Returns **Sharp** 
+
+[1]: https://nodejs.org/api/buffer.html
+
+[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+
+[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[6]: https://www.npmjs.org/package/color
+
+[7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error

docs/api-constructor.md

@@ -0,0 +1,121 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## Sharp
+
+### Parameters
+
+-   `input` **([Buffer][1] \| [String][2])?** if present, can be
+     a Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
+     a String containing the path to an JPEG, PNG, WebP, GIF, SVG or TIFF image file.
+     JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data can be streamed into the object when not present.
+-   `options` **[Object][3]?** if present, is an Object with optional attributes.
+    -   `options.failOnError` **[Boolean][4]** by default apply a "best effort"
+         to decode images, even if the data is corrupt or invalid. Set this flag to true
+         if you'd rather halt processing and raise an error when loading invalid images. (optional, default `false`)
+    -   `options.density` **[Number][5]** number representing the DPI for vector images. (optional, default `72`)
+    -   `options.page` **[Number][5]** page number to extract for multi-page input (GIF, TIFF) (optional, default `0`)
+    -   `options.raw` **[Object][3]?** describes raw pixel input image data. See `raw()` for pixel ordering.
+        -   `options.raw.width` **[Number][5]?** 
+        -   `options.raw.height` **[Number][5]?** 
+        -   `options.raw.channels` **[Number][5]?** 1-4
+    -   `options.create` **[Object][3]?** describes a new image to be created.
+        -   `options.create.width` **[Number][5]?** 
+        -   `options.create.height` **[Number][5]?** 
+        -   `options.create.channels` **[Number][5]?** 3-4
+        -   `options.create.background` **([String][2] \| [Object][3])?** parsed by the [color][6] module to extract values for red, green, blue and alpha.
+
+### Examples
+
+```javascript
+sharp('input.jpg')
+  .resize(300, 200)
+  .toFile('output.jpg', function(err) {
+    // output.jpg is a 300 pixels wide and 200 pixels high image
+    // containing a scaled and cropped version of input.jpg
+  });
+```
+
+```javascript
+// Read image data from readableStream,
+// resize to 300 pixels wide,
+// emit an 'info' event with calculated dimensions
+// and finally write image data to writableStream
+var transformer = sharp()
+  .resize(300)
+  .on('info', function(info) {
+    console.log('Image height is ' + info.height);
+  });
+readableStream.pipe(transformer).pipe(writableStream);
+```
+
+```javascript
+// Create a blank 300x200 PNG image of semi-transluent red pixels
+sharp({
+  create: {
+    width: 300,
+    height: 200,
+    channels: 4,
+    background: { r: 255, g: 0, b: 0, alpha: 0.5 }
+  }
+})
+.png()
+.toBuffer()
+.then( ... );
+```
+
+-   Throws **[Error][7]** Invalid parameters
+
+Returns **[Sharp][8]** 
+
+### format
+
+An Object containing nested boolean values representing the available input and output formats/methods.
+
+#### Examples
+
+```javascript
+console.log(sharp.format);
+```
+
+Returns **[Object][3]** 
+
+### versions
+
+An Object containing the version numbers of libvips and its dependencies.
+
+#### Examples
+
+```javascript
+console.log(sharp.versions);
+```
+
+## queue
+
+An EventEmitter that emits a `change` event when a task is either:
+
+-   queued, waiting for _libuv_ to provide a worker thread
+-   complete
+
+### Examples
+
+```javascript
+sharp.queue.on('change', function(queueLength) {
+  console.log('Queue contains ' + queueLength + ' task(s)');
+});
+```
+
+[1]: https://nodejs.org/api/buffer.html
+
+[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+
+[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+
+[6]: https://www.npmjs.org/package/color
+
+[7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+
+[8]: #sharp

docs/api-input.md

@@ -0,0 +1,150 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## clone
+
+Take a "snapshot" of the Sharp instance, returning a new instance.
+Cloned instances inherit the input of their parent instance.
+This allows multiple output Streams and therefore multiple processing pipelines to share a single input Stream.
+
+### Examples
+
+```javascript
+const pipeline = sharp().rotate();
+pipeline.clone().resize(800, 600).pipe(firstWritableStream);
+pipeline.clone().extract({ left: 20, top: 20, width: 100, height: 100 }).pipe(secondWritableStream);
+readableStream.pipe(pipeline);
+// firstWritableStream receives auto-rotated, resized readableStream
+// secondWritableStream receives auto-rotated, extracted region of readableStream
+```
+
+Returns **Sharp** 
+
+## metadata
+
+Fast access to (uncached) image metadata without decoding any compressed image data.
+A Promises/A+ promise is returned when `callback` is not provided.
+
+-   `format`: Name of decoder used to decompress image data e.g. `jpeg`, `png`, `webp`, `gif`, `svg`
+-   `size`: Total size of image in bytes, for Stream and Buffer input only
+-   `width`: Number of pixels wide (EXIF orientation is not taken into consideration)
+-   `height`: Number of pixels high (EXIF orientation is not taken into consideration)
+-   `space`: Name of colour space interpretation e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...][1]
+-   `channels`: Number of bands e.g. `3` for sRGB, `4` for CMYK
+-   `depth`: Name of pixel depth format e.g. `uchar`, `char`, `ushort`, `float` [...][2]
+-   `density`: Number of pixels per inch (DPI), if present
+-   `chromaSubsampling`: String containing JPEG chroma subsampling, `4:2:0` or `4:4:4` for RGB, `4:2:0:4` or `4:4:4:4` for CMYK
+-   `isProgressive`: Boolean indicating whether the image is interlaced using a progressive scan
+-   `pages`: Number of pages this TIFF, GIF or PDF image contains.
+-   `pageHeight`: Number of pixels high each page in this PDF image will be.
+-   `hasProfile`: Boolean indicating the presence of an embedded ICC profile
+-   `hasAlpha`: Boolean indicating the presence of an alpha transparency channel
+-   `orientation`: Number value of the EXIF Orientation header, if present
+-   `exif`: Buffer containing raw EXIF data, if present
+-   `icc`: Buffer containing raw [ICC][3] profile data, if present
+-   `iptc`: Buffer containing raw IPTC data, if present
+-   `xmp`: Buffer containing raw XMP data, if present
+
+### Parameters
+
+-   `callback` **[Function][4]?** called with the arguments `(err, metadata)`
+
+### Examples
+
+```javascript
+const image = sharp(inputJpg);
+image
+  .metadata()
+  .then(function(metadata) {
+    return image
+      .resize(Math.round(metadata.width / 2))
+      .webp()
+      .toBuffer();
+  })
+  .then(function(data) {
+    // data contains a WebP image half the width and height of the original JPEG
+  });
+```
+
+Returns **([Promise][5]&lt;[Object][6]> | Sharp)** 
+
+## stats
+
+Access to pixel-derived image statistics for every channel in the image.
+A Promise is returned when `callback` is not provided.
+
+-   `channels`: Array of channel statistics for each channel in the image. Each channel statistic contains
+    -   `min` (minimum value in the channel)
+    -   `max` (maximum value in the channel)
+    -   `sum` (sum of all values in a channel)
+    -   `squaresSum` (sum of squared values in a channel)
+    -   `mean` (mean of the values in a channel)
+    -   `stdev` (standard deviation for the values in a channel)
+    -   `minX` (x-coordinate of one of the pixel where the minimum lies)
+    -   `minY` (y-coordinate of one of the pixel where the minimum lies)
+    -   `maxX` (x-coordinate of one of the pixel where the maximum lies)
+    -   `maxY` (y-coordinate of one of the pixel where the maximum lies)
+-   `isOpaque`: Value to identify if the image is opaque or transparent, based on the presence and use of alpha channel
+-   `entropy`: Histogram-based estimation of greyscale entropy, discarding alpha channel if any (experimental)
+
+### Parameters
+
+-   `callback` **[Function][4]?** called with the arguments `(err, stats)`
+
+### Examples
+
+```javascript
+const image = sharp(inputJpg);
+image
+  .stats()
+  .then(function(stats) {
+     // stats contains the channel-wise statistics array and the isOpaque value
+  });
+```
+
+Returns **[Promise][5]&lt;[Object][6]>** 
+
+## limitInputPixels
+
+Do not process input images where the number of pixels (width _ height) exceeds this limit.
+Assumes image dimensions contained in the input metadata can be trusted.
+The default limit is 268402689 (0x3FFF _ 0x3FFF) pixels.
+
+### Parameters
+
+-   `limit` **([Number][7] \| [Boolean][8])** an integral Number of pixels, zero or false to remove limit, true to use default limit.
+
+
+-   Throws **[Error][9]** Invalid limit
+
+Returns **Sharp** 
+
+## sequentialRead
+
+An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`.
+This will reduce memory usage and can improve performance on some systems.
+
+The default behaviour _before_ function call is `false`, meaning the libvips access method is not sequential.
+
+### Parameters
+
+-   `sequentialRead` **[Boolean][8]**  (optional, default `true`)
+
+Returns **Sharp** 
+
+[1]: https://github.com/libvips/libvips/blob/master/libvips/iofuncs/enumtypes.c#L636
+
+[2]: https://github.com/libvips/libvips/blob/master/libvips/iofuncs/enumtypes.c#L672
+
+[3]: https://www.npmjs.com/package/icc
+
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function
+
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise
+
+[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+
+[8]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[9]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error

docs/api-operation.md

@@ -0,0 +1,304 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## rotate
+
+Rotate the output image by either an explicit angle
+or auto-orient based on the EXIF `Orientation` tag.
+
+If an angle is provided, it is converted to a valid positive degree rotation.
+For example, `-450` will produce a 270deg rotation.
+
+When rotating by an angle other than a multiple of 90,
+the background colour can be provided with the `background` option.
+
+If no angle is provided, it is determined from the EXIF data.
+Mirroring is supported and may infer the use of a flip operation.
+
+The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
+
+Method order is important when both rotating and extracting regions,
+for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`.
+
+### Parameters
+
+-   `angle` **[Number][1]** angle of rotation. (optional, default `auto`)
+-   `options` **[Object][2]?** if present, is an Object with optional attributes.
+    -   `options.background` **([String][3] \| [Object][2])** parsed by the [color][4] module to extract values for red, green, blue and alpha. (optional, default `"#000000"`)
+
+### Examples
+
+```javascript
+const pipeline = sharp()
+  .rotate()
+  .resize(null, 200)
+  .toBuffer(function (err, outputBuffer, info) {
+    // outputBuffer contains 200px high JPEG image data,
+    // auto-rotated using EXIF Orientation tag
+    // info.width and info.height contain the dimensions of the resized image
+  });
+readableStream.pipe(pipeline);
+```
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## flip
+
+Flip the image about the vertical Y axis. This always occurs after rotation, if any.
+The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
+
+### Parameters
+
+-   `flip` **[Boolean][6]**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## flop
+
+Flop the image about the horizontal X axis. This always occurs after rotation, if any.
+The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
+
+### Parameters
+
+-   `flop` **[Boolean][6]**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## sharpen
+
+Sharpen the image.
+When used without parameters, performs a fast, mild sharpen of the output image.
+When a `sigma` is provided, performs a slower, more accurate sharpen of the L channel in the LAB colour space.
+Separate control over the level of sharpening in "flat" and "jagged" areas is available.
+
+### Parameters
+
+-   `sigma` **[Number][1]?** the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+-   `flat` **[Number][1]** the level of sharpening to apply to "flat" areas. (optional, default `1.0`)
+-   `jagged` **[Number][1]** the level of sharpening to apply to "jagged" areas. (optional, default `2.0`)
+
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## median
+
+Apply median filter.
+When used without parameters the default window is 3x3.
+
+### Parameters
+
+-   `size` **[Number][1]** square mask size: size x size (optional, default `3`)
+
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## blur
+
+Blur the image.
+When used without parameters, performs a fast, mild blur of the output image.
+When a `sigma` is provided, performs a slower, more accurate Gaussian blur.
+
+### Parameters
+
+-   `sigma` **[Number][1]?** a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## flatten
+
+Merge alpha transparency channel, if any, with a background.
+
+### Parameters
+
+-   `options` **[Object][2]?** 
+    -   `options.background` **([String][3] \| [Object][2])** background colour, parsed by the [color][4] module, defaults to black. (optional, default `{r:0,g:0,b:0}`)
+
+Returns **Sharp** 
+
+## gamma
+
+Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma`
+then increasing the encoding (brighten) post-resize at a factor of `gamma`.
+This can improve the perceived brightness of a resized image in non-linear colour spaces.
+JPEG and WebP input images will not take advantage of the shrink-on-load performance optimisation
+when applying a gamma correction.
+
+Supply a second argument to use a different output gamma value, otherwise the first value is used in both cases.
+
+### Parameters
+
+-   `gamma` **[Number][1]** value between 1.0 and 3.0. (optional, default `2.2`)
+-   `gammaOut` **[Number][1]?** value between 1.0 and 3.0. (optional, defaults to same as `gamma`)
+
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## negate
+
+Produce the "negative" of the image.
+
+### Parameters
+
+-   `negate` **[Boolean][6]**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## normalise
+
+Enhance output image contrast by stretching its luminance to cover the full dynamic range.
+
+### Parameters
+
+-   `normalise` **[Boolean][6]**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## normalize
+
+Alternative spelling of normalise.
+
+### Parameters
+
+-   `normalize` **[Boolean][6]**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## convolve
+
+Convolve the image with the specified kernel.
+
+### Parameters
+
+-   `kernel` **[Object][2]** 
+    -   `kernel.width` **[Number][1]** width of the kernel in pixels.
+    -   `kernel.height` **[Number][1]** width of the kernel in pixels.
+    -   `kernel.kernel` **[Array][7]&lt;[Number][1]>** Array of length `width*height` containing the kernel values.
+    -   `kernel.scale` **[Number][1]** the scale of the kernel in pixels. (optional, default `sum`)
+    -   `kernel.offset` **[Number][1]** the offset of the kernel in pixels. (optional, default `0`)
+
+### Examples
+
+```javascript
+sharp(input)
+  .convolve({
+    width: 3,
+    height: 3,
+    kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1]
+  })
+  .raw()
+  .toBuffer(function(err, data, info) {
+    // data contains the raw pixel data representing the convolution
+    // of the input image with the horizontal Sobel operator
+  });
+```
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## threshold
+
+Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
+
+### Parameters
+
+-   `threshold` **[Number][1]** a value in the range 0-255 representing the level at which the threshold will be applied. (optional, default `128`)
+-   `options` **[Object][2]?** 
+    -   `options.greyscale` **[Boolean][6]** convert to single channel greyscale. (optional, default `true`)
+    -   `options.grayscale` **[Boolean][6]** alternative spelling for greyscale. (optional, default `true`)
+
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## boolean
+
+Perform a bitwise boolean operation with operand image.
+
+This operation creates an output image where each pixel is the result of
+the selected bitwise boolean `operation` between the corresponding pixels of the input images.
+
+### Parameters
+
+-   `operand` **([Buffer][8] \| [String][3])** Buffer containing image data or String containing the path to an image file.
+-   `operator` **[String][3]** one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+-   `options` **[Object][2]?** 
+    -   `options.raw` **[Object][2]?** describes operand when using raw pixel data.
+        -   `options.raw.width` **[Number][1]?** 
+        -   `options.raw.height` **[Number][1]?** 
+        -   `options.raw.channels` **[Number][1]?** 
+
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## linear
+
+Apply the linear formula a \* input + b to the image (levels adjustment)
+
+### Parameters
+
+-   `a` **[Number][1]** multiplier (optional, default `1.0`)
+-   `b` **[Number][1]** offset (optional, default `0.0`)
+
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+## recomb
+
+Recomb the image with the specified matrix.
+
+### Parameters
+
+-   `inputMatrix`  
+-   `3x3` **[Array][7]&lt;[Array][7]&lt;[Number][1]>>** Recombination matrix
+
+### Examples
+
+```javascript
+sharp(input)
+  .recomb([
+   [0.3588, 0.7044, 0.1368],
+   [0.2990, 0.5870, 0.1140],
+   [0.2392, 0.4696, 0.0912],
+  ])
+  .raw()
+  .toBuffer(function(err, data, info) {
+    // data contains the raw pixel data after applying the recomb
+    // With this example input, a sepia filter has been applied
+  });
+```
+
+-   Throws **[Error][5]** Invalid parameters
+
+Returns **Sharp** 
+
+[1]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+
+[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+
+[4]: https://www.npmjs.org/package/color
+
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+
+[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array
+
+[8]: https://nodejs.org/api/buffer.html

docs/api-output.md

@@ -0,0 +1,326 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## toFile
+
+Write output image data to a file.
+
+If an explicit output format is not selected, it will be inferred from the extension,
+with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
+Note that raw pixel data is only supported for buffer output.
+
+A `Promise` is returned when `callback` is not provided.
+
+### Parameters
+
+-   `fileOut` **[String][1]** the path to write the image data to.
+-   `callback` **[Function][2]?** called on completion with two arguments `(err, info)`.
+    `info` contains the output image `format`, `size` (bytes), `width`, `height`,
+    `channels` and `premultiplied` (indicating if premultiplication was used).
+    When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
+
+### Examples
+
+```javascript
+sharp(input)
+  .toFile('output.png', (err, info) => { ... });
+```
+
+```javascript
+sharp(input)
+  .toFile('output.png')
+  .then(info => { ... })
+  .catch(err => { ... });
+```
+
+-   Throws **[Error][3]** Invalid parameters
+
+Returns **[Promise][4]&lt;[Object][5]>** when no callback is provided
+
+## toBuffer
+
+Write output to a Buffer.
+JPEG, PNG, WebP, TIFF and RAW output are supported.
+By default, the format will match the input image, except GIF and SVG input which become PNG output.
+
+`callback`, if present, gets three arguments `(err, data, info)` where:
+
+-   `err` is an error, if any.
+-   `data` is the output image data.
+-   `info` contains the output image `format`, `size` (bytes), `width`, `height`,
+    `channels` and `premultiplied` (indicating if premultiplication was used).
+    When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
+
+A `Promise` is returned when `callback` is not provided.
+
+### Parameters
+
+-   `options` **[Object][5]?** 
+    -   `options.resolveWithObject` **[Boolean][6]?** Resolve the Promise with an Object containing `data` and `info` properties instead of resolving only with `data`.
+-   `callback` **[Function][2]?** 
+
+### Examples
+
+```javascript
+sharp(input)
+  .toBuffer((err, data, info) => { ... });
+```
+
+```javascript
+sharp(input)
+  .toBuffer()
+  .then(data => { ... })
+  .catch(err => { ... });
+```
+
+```javascript
+sharp(input)
+  .toBuffer({ resolveWithObject: true })
+  .then(({ data, info }) => { ... })
+  .catch(err => { ... });
+```
+
+Returns **[Promise][4]&lt;[Buffer][7]>** when no callback is provided
+
+## withMetadata
+
+Include all metadata (EXIF, XMP, IPTC) from the input image in the output image.
+The default behaviour, when `withMetadata` is not used, is to strip all metadata and convert to the device-independent sRGB colour space.
+This will also convert to and add a web-friendly sRGB ICC profile.
+
+### Parameters
+
+-   `withMetadata` **[Object][5]?** 
+    -   `withMetadata.orientation` **[Number][8]?** value between 1 and 8, used to update the EXIF `Orientation` tag.
+
+### Examples
+
+```javascript
+sharp('input.jpg')
+  .withMetadata()
+  .toFile('output-with-metadata.jpg')
+  .then(info => { ... });
+```
+
+-   Throws **[Error][3]** Invalid parameters
+
+Returns **Sharp** 
+
+## jpeg
+
+Use these JPEG options for output image.
+
+### Parameters
+
+-   `options` **[Object][5]?** output options
+    -   `options.quality` **[Number][8]** quality, integer 1-100 (optional, default `80`)
+    -   `options.progressive` **[Boolean][6]** use progressive (interlace) scan (optional, default `false`)
+    -   `options.chromaSubsampling` **[String][1]** set to '4:4:4' to prevent chroma subsampling when quality &lt;= 90 (optional, default `'4:2:0'`)
+    -   `options.trellisQuantisation` **[Boolean][6]** apply trellis quantisation, requires mozjpeg (optional, default `false`)
+    -   `options.overshootDeringing` **[Boolean][6]** apply overshoot deringing, requires mozjpeg (optional, default `false`)
+    -   `options.optimiseScans` **[Boolean][6]** optimise progressive scans, forces progressive, requires mozjpeg (optional, default `false`)
+    -   `options.optimizeScans` **[Boolean][6]** alternative spelling of optimiseScans (optional, default `false`)
+    -   `options.optimiseCoding` **[Boolean][6]** optimise Huffman coding tables (optional, default `true`)
+    -   `options.optimizeCoding` **[Boolean][6]** alternative spelling of optimiseCoding (optional, default `true`)
+    -   `options.quantisationTable` **[Number][8]** quantization table to use, integer 0-8, requires mozjpeg (optional, default `0`)
+    -   `options.quantizationTable` **[Number][8]** alternative spelling of quantisationTable (optional, default `0`)
+    -   `options.force` **[Boolean][6]** force JPEG output, otherwise attempt to use input format (optional, default `true`)
+
+### Examples
+
+```javascript
+// Convert any input to very high quality JPEG output
+const data = await sharp(input)
+  .jpeg({
+    quality: 100,
+    chromaSubsampling: '4:4:4'
+  })
+  .toBuffer();
+```
+
+-   Throws **[Error][3]** Invalid options
+
+Returns **Sharp** 
+
+## png
+
+Use these PNG options for output image.
+
+PNG output is always full colour at 8 or 16 bits per pixel.
+Indexed PNG input at 1, 2 or 4 bits per pixel is converted to 8 bits per pixel.
+
+### Parameters
+
+-   `options` **[Object][5]?** 
+    -   `options.progressive` **[Boolean][6]** use progressive (interlace) scan (optional, default `false`)
+    -   `options.compressionLevel` **[Number][8]** zlib compression level, 0-9 (optional, default `9`)
+    -   `options.adaptiveFiltering` **[Boolean][6]** use adaptive row filtering (optional, default `false`)
+    -   `options.palette` **[Boolean][6]** quantise to a palette-based image with alpha transparency support, requires libimagequant (optional, default `false`)
+    -   `options.quality` **[Number][8]** use the lowest number of colours needed to achieve given quality, requires libimagequant (optional, default `100`)
+    -   `options.colours` **[Number][8]** maximum number of palette entries, requires libimagequant (optional, default `256`)
+    -   `options.colors` **[Number][8]** alternative spelling of `options.colours`, requires libimagequant (optional, default `256`)
+    -   `options.dither` **[Number][8]** level of Floyd-Steinberg error diffusion, requires libimagequant (optional, default `1.0`)
+    -   `options.force` **[Boolean][6]** force PNG output, otherwise attempt to use input format (optional, default `true`)
+
+### Examples
+
+```javascript
+// Convert any input to PNG output
+const data = await sharp(input)
+  .png()
+  .toBuffer();
+```
+
+-   Throws **[Error][3]** Invalid options
+
+Returns **Sharp** 
+
+## webp
+
+Use these WebP options for output image.
+
+### Parameters
+
+-   `options` **[Object][5]?** output options
+    -   `options.quality` **[Number][8]** quality, integer 1-100 (optional, default `80`)
+    -   `options.alphaQuality` **[Number][8]** quality of alpha layer, integer 0-100 (optional, default `100`)
+    -   `options.lossless` **[Boolean][6]** use lossless compression mode (optional, default `false`)
+    -   `options.nearLossless` **[Boolean][6]** use near_lossless compression mode (optional, default `false`)
+    -   `options.force` **[Boolean][6]** force WebP output, otherwise attempt to use input format (optional, default `true`)
+
+### Examples
+
+```javascript
+// Convert any input to lossless WebP output
+const data = await sharp(input)
+  .webp({ lossless: true })
+  .toBuffer();
+```
+
+-   Throws **[Error][3]** Invalid options
+
+Returns **Sharp** 
+
+## tiff
+
+Use these TIFF options for output image.
+
+### Parameters
+
+-   `options` **[Object][5]?** output options
+    -   `options.quality` **[Number][8]** quality, integer 1-100 (optional, default `80`)
+    -   `options.force` **[Boolean][6]** force TIFF output, otherwise attempt to use input format (optional, default `true`)
+    -   `options.compression` **[Boolean][6]** compression options: lzw, deflate, jpeg, ccittfax4 (optional, default `'jpeg'`)
+    -   `options.predictor` **[Boolean][6]** compression predictor options: none, horizontal, float (optional, default `'horizontal'`)
+    -   `options.pyramid` **[Boolean][6]** write an image pyramid (optional, default `false`)
+    -   `options.tile` **[Boolean][6]** write a tiled tiff (optional, default `false`)
+    -   `options.tileWidth` **[Boolean][6]** horizontal tile size (optional, default `256`)
+    -   `options.tileHeight` **[Boolean][6]** vertical tile size (optional, default `256`)
+    -   `options.xres` **[Number][8]** horizontal resolution in pixels/mm (optional, default `1.0`)
+    -   `options.yres` **[Number][8]** vertical resolution in pixels/mm (optional, default `1.0`)
+    -   `options.squash` **[Boolean][6]** squash 8-bit images down to 1 bit (optional, default `false`)
+
+### Examples
+
+```javascript
+// Convert SVG input to LZW-compressed, 1 bit per pixel TIFF output
+sharp('input.svg')
+  .tiff({
+    compression: 'lzw',
+    squash: true
+  })
+  .toFile('1-bpp-output.tiff')
+  .then(info => { ... });
+```
+
+-   Throws **[Error][3]** Invalid options
+
+Returns **Sharp** 
+
+## raw
+
+Force output to be raw, uncompressed uint8 pixel data.
+
+### Examples
+
+```javascript
+// Extract raw RGB pixel data from JPEG input
+const { data, info } = await sharp('input.jpg')
+  .raw()
+  .toBuffer({ resolveWithObject: true });
+```
+
+Returns **Sharp** 
+
+## toFormat
+
+Force output to a given format.
+
+### Parameters
+
+-   `format` **([String][1] \| [Object][5])** as a String or an Object with an 'id' attribute
+-   `options` **[Object][5]** output options
+
+### Examples
+
+```javascript
+// Convert any input to PNG output
+const data = await sharp(input)
+  .toFormat('png')
+  .toBuffer();
+```
+
+-   Throws **[Error][3]** unsupported format or options
+
+Returns **Sharp** 
+
+## tile
+
+Use tile-based deep zoom (image pyramid) output.
+Set the format and options for tile images via the `toFormat`, `jpeg`, `png` or `webp` functions.
+Use a `.zip` or `.szi` file extension with `toFile` to write to a compressed archive file format.
+
+Warning: multiple sharp instances concurrently producing tile output can expose a possible race condition in some versions of libgsf.
+
+### Parameters
+
+-   `tile` **[Object][5]?** 
+    -   `tile.size` **[Number][8]** tile size in pixels, a value between 1 and 8192. (optional, default `256`)
+    -   `tile.overlap` **[Number][8]** tile overlap in pixels, a value between 0 and 8192. (optional, default `0`)
+    -   `tile.angle` **[Number][8]** tile angle of rotation, must be a multiple of 90. (optional, default `0`)
+    -   `tile.depth` **[String][1]?** how deep to make the pyramid, possible values are `onepixel`, `onetile` or `one`, default based on layout.
+    -   `tile.container` **[String][1]** tile container, with value `fs` (filesystem) or `zip` (compressed file). (optional, default `'fs'`)
+    -   `tile.layout` **[String][1]** filesystem layout, possible values are `dz`, `zoomify` or `google`. (optional, default `'dz'`)
+
+### Examples
+
+```javascript
+sharp('input.tiff')
+  .png()
+  .tile({
+    size: 512
+  })
+  .toFile('output.dz', function(err, info) {
+    // output.dzi is the Deep Zoom XML definition
+    // output_files contains 512x512 tiles grouped by zoom level
+  });
+```
+
+-   Throws **[Error][3]** Invalid parameters
+
+Returns **Sharp** 
+
+[1]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+
+[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function
+
+[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise
+
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[7]: https://nodejs.org/api/buffer.html
+
+[8]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number

docs/api-resize.md

@@ -0,0 +1,234 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## resize
+
+Resize image to `width`, `height` or `width x height`.
+
+When both a `width` and `height` are provided, the possible methods by which the image should **fit** these are:
+
+-   `cover`: Crop to cover both provided dimensions (the default).
+-   `contain`: Embed within both provided dimensions.
+-   `fill`: Ignore the aspect ratio of the input and stretch to both provided dimensions.
+-   `inside`: Preserving aspect ratio, resize the image to be as large as possible while ensuring its dimensions are less than or equal to both those specified.
+-   `outside`: Preserving aspect ratio, resize the image to be as small as possible while ensuring its dimensions are greater than or equal to both those specified.
+    Some of these values are based on the [object-fit][1] CSS property.
+
+When using a `fit` of `cover` or `contain`, the default **position** is `centre`. Other options are:
+
+-   `sharp.position`: `top`, `right top`, `right`, `right bottom`, `bottom`, `left bottom`, `left`, `left top`.
+-   `sharp.gravity`: `north`, `northeast`, `east`, `southeast`, `south`, `southwest`, `west`, `northwest`, `center` or `centre`.
+-   `sharp.strategy`: `cover` only, dynamically crop using either the `entropy` or `attention` strategy.
+    Some of these values are based on the [object-position][2] CSS property.
+
+The experimental strategy-based approach resizes so one dimension is at its target length
+then repeatedly ranks edge regions, discarding the edge with the lowest score based on the selected strategy.
+
+-   `entropy`: focus on the region with the highest [Shannon entropy][3].
+-   `attention`: focus on the region with the highest luminance frequency, colour saturation and presence of skin tones.
+
+Possible interpolation kernels are:
+
+-   `nearest`: Use [nearest neighbour interpolation][4].
+-   `cubic`: Use a [Catmull-Rom spline][5].
+-   `mitchell`: Use a [Mitchell-Netravali spline][6].
+-   `lanczos2`: Use a [Lanczos kernel][7] with `a=2`.
+-   `lanczos3`: Use a Lanczos kernel with `a=3` (the default).
+
+### Parameters
+
+-   `width` **[Number][8]?** pixels wide the resultant image should be. Use `null` or `undefined` to auto-scale the width to match the height.
+-   `height` **[Number][8]?** pixels high the resultant image should be. Use `null` or `undefined` to auto-scale the height to match the width.
+-   `options` **[Object][9]?** 
+    -   `options.width` **[String][10]?** alternative means of specifying `width`. If both are present this take priority.
+    -   `options.height` **[String][10]?** alternative means of specifying `height`. If both are present this take priority.
+    -   `options.fit` **[String][10]** how the image should be resized to fit both provided dimensions, one of `cover`, `contain`, `fill`, `inside` or `outside`. (optional, default `'cover'`)
+    -   `options.position` **[String][10]** position, gravity or strategy to use when `fit` is `cover` or `contain`. (optional, default `'centre'`)
+    -   `options.background` **([String][10] \| [Object][9])** background colour when using a `fit` of `contain`, parsed by the [color][11] module, defaults to black without transparency. (optional, default `{r:0,g:0,b:0,alpha:1}`)
+    -   `options.kernel` **[String][10]** the kernel to use for image reduction. (optional, default `'lanczos3'`)
+    -   `options.withoutEnlargement` **[Boolean][12]** do not enlarge if the width _or_ height are already less than the specified dimensions, equivalent to GraphicsMagick's `>` geometry option. (optional, default `false`)
+    -   `options.fastShrinkOnLoad` **[Boolean][12]** take greater advantage of the JPEG and WebP shrink-on-load feature, which can lead to a slight moiré pattern on some images. (optional, default `true`)
+
+### Examples
+
+```javascript
+sharp(input)
+  .resize({ width: 100 })
+  .toBuffer()
+  .then(data => {
+    // 100 pixels wide, auto-scaled height
+  });
+```
+
+```javascript
+sharp(input)
+  .resize({ height: 100 })
+  .toBuffer()
+  .then(data => {
+    // 100 pixels high, auto-scaled width
+  });
+```
+
+```javascript
+sharp(input)
+  .resize(200, 300, {
+    kernel: sharp.kernel.nearest,
+    fit: 'contain',
+    position: 'right top',
+    background: { r: 255, g: 255, b: 255, alpha: 0.5 }
+  })
+  .toFile('output.png')
+  .then(() => {
+    // output.png is a 200 pixels wide and 300 pixels high image
+    // containing a nearest-neighbour scaled version
+    // contained within the north-east corner of a semi-transparent white canvas
+  });
+```
+
+```javascript
+const transformer = sharp()
+  .resize({
+    width: 200,
+    height: 200,
+    fit: sharp.fit.cover,
+    position: sharp.strategy.entropy
+  });
+// Read image data from readableStream
+// Write 200px square auto-cropped image data to writableStream
+readableStream
+  .pipe(transformer)
+  .pipe(writableStream);
+```
+
+```javascript
+sharp(input)
+  .resize(200, 200, {
+    fit: sharp.fit.inside,
+    withoutEnlargement: true
+  })
+  .toFormat('jpeg')
+  .toBuffer()
+  .then(function(outputBuffer) {
+    // outputBuffer contains JPEG image data
+    // no wider and no higher than 200 pixels
+    // and no larger than the input image
+  });
+```
+
+-   Throws **[Error][13]** Invalid parameters
+
+Returns **Sharp** 
+
+## extend
+
+Extends/pads the edges of the image with the provided background colour.
+This operation will always occur after resizing and extraction, if any.
+
+### Parameters
+
+-   `extend` **([Number][8] \| [Object][9])** single pixel count to add to all edges or an Object with per-edge counts
+    -   `extend.top` **[Number][8]?** 
+    -   `extend.left` **[Number][8]?** 
+    -   `extend.bottom` **[Number][8]?** 
+    -   `extend.right` **[Number][8]?** 
+    -   `extend.background` **([String][10] \| [Object][9])** background colour, parsed by the [color][11] module, defaults to black without transparency. (optional, default `{r:0,g:0,b:0,alpha:1}`)
+
+### Examples
+
+```javascript
+// Resize to 140 pixels wide, then add 10 transparent pixels
+// to the top, left and right edges and 20 to the bottom edge
+sharp(input)
+  .resize(140)
+  .extend({
+    top: 10,
+    bottom: 20,
+    left: 10,
+    right: 10
+    background: { r: 0, g: 0, b: 0, alpha: 0 }
+  })
+  ...
+```
+
+-   Throws **[Error][13]** Invalid parameters
+
+Returns **Sharp** 
+
+## extract
+
+Extract a region of the image.
+
+-   Use `extract` before `resize` for pre-resize extraction.
+-   Use `extract` after `resize` for post-resize extraction.
+-   Use `extract` before and after for both.
+
+### Parameters
+
+-   `options` **[Object][9]** 
+    -   `options.left` **[Number][8]** zero-indexed offset from left edge
+    -   `options.top` **[Number][8]** zero-indexed offset from top edge
+    -   `options.width` **[Number][8]** dimension of extracted image
+    -   `options.height` **[Number][8]** dimension of extracted image
+
+### Examples
+
+```javascript
+sharp(input)
+  .extract({ left: left, top: top, width: width, height: height })
+  .toFile(output, function(err) {
+    // Extract a region of the input image, saving in the same format.
+  });
+```
+
+```javascript
+sharp(input)
+  .extract({ left: leftOffsetPre, top: topOffsetPre, width: widthPre, height: heightPre })
+  .resize(width, height)
+  .extract({ left: leftOffsetPost, top: topOffsetPost, width: widthPost, height: heightPost })
+  .toFile(output, function(err) {
+    // Extract a region, resize, then extract from the resized image
+  });
+```
+
+-   Throws **[Error][13]** Invalid parameters
+
+Returns **Sharp** 
+
+## trim
+
+Trim "boring" pixels from all edges that contain values similar to the top-left pixel.
+The `info` response Object will contain `trimOffsetLeft` and `trimOffsetTop` properties.
+
+### Parameters
+
+-   `threshold` **[Number][8]** the allowed difference from the top-left pixel, a number greater than zero. (optional, default `10`)
+
+
+-   Throws **[Error][13]** Invalid parameters
+
+Returns **Sharp** 
+
+[1]: https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit
+
+[2]: https://developer.mozilla.org/en-US/docs/Web/CSS/object-position
+
+[3]: https://en.wikipedia.org/wiki/Entropy_%28information_theory%29
+
+[4]: http://en.wikipedia.org/wiki/Nearest-neighbor_interpolation
+
+[5]: https://en.wikipedia.org/wiki/Centripetal_Catmull%E2%80%93Rom_spline
+
+[6]: https://www.cs.utexas.edu/~fussell/courses/cs384g-fall2013/lectures/mitchell/Mitchell.pdf
+
+[7]: https://en.wikipedia.org/wiki/Lanczos_resampling#Lanczos_kernel
+
+[8]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+
+[9]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[10]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+
+[11]: https://www.npmjs.org/package/color
+
+[12]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[13]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error

docs/api-utility.md

@@ -0,0 +1,102 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+## cache
+
+Gets or, when options are provided, sets the limits of _libvips'_ operation cache.
+Existing entries in the cache will be trimmed after any change in limits.
+This method always returns cache statistics,
+useful for determining how much working memory is required for a particular task.
+
+### Parameters
+
+-   `options` **([Object][1] \| [Boolean][2])** Object with the following attributes, or Boolean where true uses default cache settings and false removes all caching (optional, default `true`)
+    -   `options.memory` **[Number][3]** is the maximum memory in MB to use for this cache (optional, default `50`)
+    -   `options.files` **[Number][3]** is the maximum number of files to hold open (optional, default `20`)
+    -   `options.items` **[Number][3]** is the maximum number of operations to cache (optional, default `100`)
+
+### Examples
+
+```javascript
+const stats = sharp.cache();
+```
+
+```javascript
+sharp.cache( { items: 200 } );
+sharp.cache( { files: 0 } );
+sharp.cache(false);
+```
+
+Returns **[Object][1]** 
+
+## concurrency
+
+Gets or, when a concurrency is provided, sets
+the number of threads _libvips'_ should create to process each image.
+The default value is the number of CPU cores.
+A value of `0` will reset to this default.
+
+The maximum number of images that can be processed in parallel
+is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
+
+This method always returns the current concurrency.
+
+### Parameters
+
+-   `concurrency` **[Number][3]?** 
+
+### Examples
+
+```javascript
+const threads = sharp.concurrency(); // 4
+sharp.concurrency(2); // 2
+sharp.concurrency(0); // 4
+```
+
+Returns **[Number][3]** concurrency
+
+## counters
+
+Provides access to internal task counters.
+
+-   queue is the number of tasks this module has queued waiting for _libuv_ to provide a worker thread from its pool.
+-   process is the number of resize tasks currently being processed.
+
+### Examples
+
+```javascript
+const counters = sharp.counters(); // { queue: 2, process: 4 }
+```
+
+Returns **[Object][1]** 
+
+## simd
+
+Get and set use of SIMD vector unit instructions.
+Requires libvips to have been compiled with liborc support.
+
+Improves the performance of `resize`, `blur` and `sharpen` operations
+by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM NEON.
+
+### Parameters
+
+-   `simd` **[Boolean][2]**  (optional, default `true`)
+
+### Examples
+
+```javascript
+const simd = sharp.simd();
+// simd is `true` if the runtime use of liborc is currently enabled
+```
+
+```javascript
+const simd = sharp.simd(false);
+// prevent libvips from using liborc at runtime
+```
+
+Returns **[Boolean][2]** 
+
+[1]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number

docs/api.md

@@ -1,737 +0,0 @@
-# API
-
-```javascript
-var sharp = require('sharp');
-```
-
-### Input
-
-#### sharp([input], [options])
-
-Constructor to which further methods are chained.
-
-`input`, if present, can be one of:
-
-* Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
-* String containing the path to an image file, with most major formats supported.
-
-JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data
-can be streamed into the object when `input` is `null` or `undefined`.
-
-`options`, if present, is an Object with the following optional attributes:
-
-* `density` an integral number representing the DPI for vector images, defaulting to 72.
-* `raw` an Object containing `width`, `height` and `channels` when providing uncompressed data. See `raw()` for pixel ordering.
-
-The object returned by the constructor implements the
-[stream.Duplex](http://nodejs.org/api/stream.html#stream_class_stream_duplex) class.
-
-JPEG, PNG or WebP format image data can be streamed out from this object.
-When using Stream based output, derived attributes are available from the `info` event.
-
-```javascript
-sharp('input.jpg')
-  .resize(300, 200)
-  .toFile('output.jpg', function(err) {
-    // output.jpg is a 300 pixels wide and 200 pixels high image
-    // containing a scaled and cropped version of input.jpg
-  });
-```
-
-```javascript
-// Read image data from readableStream,
-// resize to 300 pixels wide,
-// emit an 'info' event with calculated dimensions
-// and finally write image data to writableStream
-var transformer = sharp()
-  .resize(300)
-  .on('info', function(info) {
-    console.log('Image height is ' + info.height);
-  });
-readableStream.pipe(transformer).pipe(writableStream);
-```
-
-#### metadata([callback])
-
-Fast access to image metadata without decoding any compressed image data.
-
-`callback`, if present, gets the arguments `(err, metadata)` where `metadata` has the attributes:
-
-* `format`: Name of decoder to be used to decompress image data e.g. `jpeg`, `png`, `webp` (for file-based input additionally `tiff`, `magick`, `openslide`, `ppm`, `fits`)
-* `width`: Number of pixels wide
-* `height`: Number of pixels high
-* `space`: Name of colour space interpretation e.g. `srgb`, `rgb`, `scrgb`, `cmyk`, `lab`, `xyz`, `b-w` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L522)
-* `channels`: Number of bands e.g. `3` for sRGB, `4` for CMYK
-* `density`: Number of pixels per inch (DPI), if present
-* `hasProfile`: Boolean indicating the presence of an embedded ICC profile
-* `hasAlpha`: Boolean indicating the presence of an alpha transparency channel
-* `orientation`: Number value of the EXIF Orientation header, if present
-* `exif`: Buffer containing raw EXIF data, if present
-* `icc`: Buffer containing raw [ICC](https://www.npmjs.com/package/icc) profile data, if present
-
-A Promises/A+ promise is returned when `callback` is not provided.
-
-```javascript
-var image = sharp(inputJpg);
-image
-  .metadata()
-  .then(function(metadata) {
-    return image
-      .resize(Math.round(metadata.width / 2))
-      .webp()
-      .toBuffer();
-  })
-  .then(function(data) {
-    // data contains a WebP image half the width and height of the original JPEG
-  });
-```
-
-#### clone()
-
-Takes a "snapshot" of the instance, returning a new instance.
-Cloned instances inherit the input of their parent instance.
-
-This allows multiple output Streams
-and therefore multiple processing pipelines
-to share a single input Stream.
-
-```javascript
-var pipeline = sharp().rotate();
-pipeline.clone().resize(800, 600).pipe(firstWritableStream);
-pipeline.clone().extract({ left: 20, top: 20, width: 100, height: 100 }).pipe(secondWritableStream);
-readableStream.pipe(pipeline);
-// firstWritableStream receives auto-rotated, resized readableStream
-// secondWritableStream receives auto-rotated, extracted region of readableStream
-```
-
-#### sequentialRead()
-
-An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`.
-This will reduce memory usage and can improve performance on some systems.
-
-#### limitInputPixels(pixels)
-
-Do not process input images where the number of pixels (width * height) exceeds this limit.
-
-`pixels` is either an integral Number of pixels, with a value between 1 and the default 268402689 (0x3FFF * 0x3FFF) or
- a boolean. `false` will disable checking while `true` will revert to the default limit.
-
-### Resizing
-
-#### resize([width], [height])
-
-Scale output to `width` x `height`. By default, the resized image is cropped to the exact size specified.
-
-`width` is the integral Number of pixels wide the resultant image should be, between 1 and 16383 (0x3FFF). Use `null` or `undefined` to auto-scale the width to match the height.
-
-`height` is the integral Number of pixels high the resultant image should be, between 1 and 16383. Use `null` or `undefined` to auto-scale the height to match the width.
-
-#### crop([option])
-
-Crop the resized image to the exact size specified, the default behaviour.
-
-`option`, if present, is an attribute of:
-
-* `sharp.gravity` e.g. `sharp.gravity.north`, to crop to an edge or corner, or
-* `sharp.strategy` e.g. `sharp.strategy.entropy`, to crop dynamically.
-
-Possible attributes of `sharp.gravity` are
-`north`, `northeast`, `east`, `southeast`, `south`,
-`southwest`, `west`, `northwest`, `center` and `centre`.
-
-Possible attributes of the experimental `sharp.strategy` are:
-
-* `entropy`: resize so one dimension is at its target size
-then repeatedly remove pixels from the edge with the lowest
-[Shannon entropy](https://en.wikipedia.org/wiki/Entropy_%28information_theory%29)
-until it too reaches the target size.
-
-The default crop option is a `center`/`centre` gravity.
-
-```javascript
-var transformer = sharp()
-  .resize(200, 200)
-  .crop(sharp.strategy.entropy)
-  .on('error', function(err) {
-    console.log(err);
-  });
-// Read image data from readableStream
-// Write 200px square auto-cropped image data to writableStream
-readableStream.pipe(transformer).pipe(writableStream);
-```
-
-#### embed()
-
-Preserving aspect ratio, resize the image to the
-maximum `width` or `height` specified
-then embed on a background of the exact
-`width` and `height` specified.
-
-If the background contains an alpha value
-then WebP and PNG format output images will
-contain an alpha channel,
-even when the input image does not.
-
-```javascript
-sharp('input.gif')
-  .resize(200, 300)
-  .background({r: 0, g: 0, b: 0, a: 0})
-  .embed()
-  .toFormat(sharp.format.webp)
-  .toBuffer(function(err, outputBuffer) {
-    if (err) {
-      throw err;
-    }
-    // outputBuffer contains WebP image data of a 200 pixels wide and 300 pixels high
-    // containing a scaled version, embedded on a transparent canvas, of input.gif
-  });
-```
-
-#### max()
-
-Preserving aspect ratio,
-resize the image to be as large as possible
-while ensuring its dimensions are less than or equal to
-the `width` and `height` specified.
-
-Both `width` and `height` must be provided via
-`resize` otherwise the behaviour will default to `crop`.
-
-```javascript
-sharp(inputBuffer)
-  .resize(200, 200)
-  .max()
-  .toFormat('jpeg')
-  .toBuffer()
-  .then(function(outputBuffer) {
-    // outputBuffer contains JPEG image data no wider than 200 pixels and no higher
-    // than 200 pixels regardless of the inputBuffer image dimensions
-  });
-```
-
-#### min()
-
-Preserving aspect ratio,
-resize the image to be as small as possible
-while ensuring its dimensions are greater than or equal to
-the `width` and `height` specified.
-
-Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
-
-#### withoutEnlargement()
-
-Do not enlarge the output image
-if the input image width *or* height
-are already less than the required dimensions.
-
-This is equivalent to GraphicsMagick's `>` geometry option:
-"*change the dimensions of the image only
-if its width or height exceeds the geometry specification*".
-
-#### ignoreAspectRatio()
-
-Ignoring the aspect ratio of the input, stretch the image to the exact `width` and/or `height` provided via `resize`.
-
-#### interpolateWith(interpolator)
-
-Use the given interpolator for image resizing, where `interpolator` is an attribute of the `sharp.interpolator` Object e.g. `sharp.interpolator.bicubic`.
-
-The default interpolator is `bicubic`, providing a general-purpose interpolator that is both fast and of good quality.
-
-Possible interpolators, in order of performance, are:
-
-* `nearest`: Use [nearest neighbour interpolation](http://en.wikipedia.org/wiki/Nearest-neighbor_interpolation), suitable for image enlargement only.
-* `bilinear`: Use [bilinear interpolation](http://en.wikipedia.org/wiki/Bilinear_interpolation), faster than bicubic but with less smooth results.
-* `vertexSplitQuadraticBasisSpline`: Use the smoother [VSQBS interpolation](https://github.com/jcupitt/libvips/blob/master/libvips/resample/vsqbs.cpp#L48) to prevent "staircasing" when enlarging.
-* `bicubic`: Use [bicubic interpolation](http://en.wikipedia.org/wiki/Bicubic_interpolation) (the default).
-* `locallyBoundedBicubic`: Use [LBB interpolation](https://github.com/jcupitt/libvips/blob/master/libvips/resample/lbb.cpp#L100), which prevents some "[acutance](http://en.wikipedia.org/wiki/Acutance)" but typically reduces performance by a factor of 2.
-* `nohalo`: Use [Nohalo interpolation](http://eprints.soton.ac.uk/268086/), which prevents acutance but typically reduces performance by a factor of 3.
-
-[Compare the output of these interpolators](https://github.com/lovell/sharp/tree/master/test/interpolators)
-
-```javascript
-sharp(inputBuffer)
-  .resize(200, 300)
-  .interpolateWith(sharp.interpolator.nohalo)
-  .background('white')
-  .embed()
-  .toFile('output.tiff')
-  .then(function() {
-    // output.tiff is a 200 pixels wide and 300 pixels high image
-    // containing a nohalo scaled version, embedded on a white canvas,
-    // of the image data in inputBuffer
-  });
-```
-
-### Operations
-
-#### extract({ left: left, top: top, width: width, height: height })
-
-Extract a region of the image. Can be used with or without a `resize` operation.
-
-`left` and `top` are the offset, in pixels, from the top-left corner.
-
-`width` and `height` are the dimensions of the extracted image.
-
-Use `extract` before `resize` for pre-resize extraction. Use `extract` after `resize` for post-resize extraction. Use `extract` before and after for both.
-
-```javascript
-sharp(input)
-  .extract({ left: left, top: top, width: width, height: height })
-  .toFile(output, function(err) {
-    // Extract a region of the input image, saving in the same format.
-  });
-```
-
-```javascript
-sharp(input)
-  .extract({ left: leftOffsetPre, top: topOffsetPre, width: widthPre, height: heightPre })
-  .resize(width, height)
-  .extract({ left: leftOffsetPost, top: topOffsetPost, width: widthPost, height: heightPost })
-  .toFile(output, function(err) {
-    // Extract a region, resize, then extract from the resized image
-  });
-```
-
-#### background(rgba)
-
-Set the background for the `embed`, `flatten` and `extend` operations.
-
-`rgba` is parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
-
-The alpha value is a float between `0` (transparent) and `1` (opaque).
-
-The default background is `{r: 0, g: 0, b: 0, a: 1}`, black without transparency.
-
-#### flatten()
-
-Merge alpha transparency channel, if any, with `background`.
-
-#### extend(extension)
-
-Extends/pads the edges of the image with `background`, where `extension` is one of:
-
-* a Number representing the pixel count to add to each edge, or
-* an Object containing `top`, `left`, `bottom` and `right` attributes, each a Number of pixels to add to that edge.
-
-This operation will always occur after resizing and extraction, if any.
-
-```javascript
-// Resize to 140 pixels wide, then add 10 transparent pixels
-// to the top, left and right edges and 20 to the bottom edge
-sharp(input)
-  .resize(140)
-  .background({r: 0, g: 0, b: 0, a: 0})
-  .extend({top: 10, bottom: 20, left: 10, right: 10})
-  ...
-```
-
-#### negate()
-
-Produces the "negative" of the image.  White => Black, Black => White, Blue => Yellow, etc.
-
-#### rotate([angle])
-
-Rotate the output image by either an explicit angle or auto-orient based on the EXIF `Orientation` tag.
-
-`angle`, if present, is a Number with a value of `0`, `90`, `180` or `270`.
-
-Use this method without `angle` to determine the angle from EXIF data. Mirroring is supported and may infer the use of a `flip` operation.
-
-Method order is important when both rotating and extracting regions, for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`.
-
-The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
-
-```javascript
-var pipeline = sharp()
-  .rotate()
-  .resize(null, 200)
-  .progressive()
-  .toBuffer(function(err, outputBuffer, info) {
-    if (err) {
-      throw err;
-    }
-    // outputBuffer contains 200px high progressive JPEG image data,
-    // auto-rotated using EXIF Orientation tag
-    // info.width and info.height contain the dimensions of the resized image
-  });
-readableStream.pipe(pipeline);
-```
-
-#### flip()
-
-Flip the image about the vertical Y axis. This always occurs after rotation, if any.
-The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
-
-#### flop()
-
-Flop the image about the horizontal X axis. This always occurs after rotation, if any.
-The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
-
-#### blur([sigma])
-
-When used without parameters, performs a fast, mild blur of the output image. This typically reduces performance by 10%.
-
-When a `sigma` is provided, performs a slower, more accurate Gaussian blur. This typically reduces performance by 25%.
-
-* `sigma`, if present, is a Number between 0.3 and 1000 representing the approximate blur radius in pixels.
-
-#### sharpen([radius], [flat], [jagged])
-
-When used without parameters, performs a fast, mild sharpen of the output image. This typically reduces performance by 10%.
-
-When a `radius` is provided, performs a slower, more accurate sharpen of the L channel in the LAB colour space. Separate control over the level of sharpening in "flat" and "jagged" areas is available. This typically reduces performance by 50%.
-
-* `radius`, if present, is an integral Number representing the sharpen mask radius in pixels.
-* `flat`, if present, is a Number representing the level of sharpening to apply to "flat" areas, defaulting to a value of 1.0.
-* `jagged`, if present, is a Number representing the level of sharpening to apply to "jagged" areas, defaulting to a value of 2.0.
-
-#### threshold([threshold])
-
-Converts all pixels in the image to greyscale white or black.  Any pixel greather-than-or-equal-to the threshold (0..255) will be white.  All others will be black.
-
-* `threshold`, if present, is a Number, representing the level above which pixels will be forced to white.
-
-#### gamma([gamma])
-
-Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma` then increasing the encoding (brighten) post-resize at a factor of `gamma`.
-
-`gamma`, if present, is a Number between 1 and 3. The default value is `2.2`, a suitable approximation for sRGB images.
-
-This can improve the perceived brightness of a resized image in non-linear colour spaces.
-
-JPEG input images will not take advantage of the shrink-on-load performance optimisation when applying a gamma correction.
-
-#### grayscale() / greyscale()
-
-Convert to 8-bit greyscale; 256 shades of grey.
-
-This is a linear operation. If the input image is in a non-linear colour space such as sRGB, use `gamma()` with `greyscale()` for the best results.
-
-The output image will still be web-friendly sRGB and contain three (identical) channels.
-
-#### normalize() / normalise()
-
-Enhance output image contrast by stretching its luminance to cover the full dynamic range. This typically reduces performance by 30%.
-
-#### overlayWith(image, [options])
-
-Overlay (composite) a image containing an alpha channel over the processed (resized, extracted etc.) image.
-
-`image` is one of the following, and must be the same size or smaller than the processed image:
-
-* Buffer containing PNG, WebP, GIF or SVG image data, or
-* String containing the path to an image file, with most major transparency formats supported.
-
-`options`, if present, is an Object with the following optional attributes:
-
-* `gravity` is a String or an attribute of the `sharp.gravity` Object e.g. `sharp.gravity.north` at which to place the overlay, defaulting to `center`/`centre`.
-
-```javascript
-sharp('input.png')
-  .rotate(180)
-  .resize(300)
-  .flatten()
-  .background('#ff6600')
-  .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
-  .sharpen()
-  .withMetadata()
-  .quality(90)
-  .webp()
-  .toBuffer()
-  .then(function(outputBuffer) {
-    // outputBuffer contains upside down, 300px wide, alpha channel flattened
-    // onto orange background, composited with overlay.png with SE gravity,
-    // sharpened, with metadata, 90% quality WebP image data. Phew!
-  });
-```
-
-### Output
-
-#### toFile(path, [callback])
-
-`path` is a String containing the path to write the image data to.
-
-If an explicit output format is not selected, it will be inferred from the extension, with JPEG, PNG, WebP, TIFF and DZI supported.
-
-`callback`, if present, is called with two arguments `(err, info)` where:
-
-* `err` contains an error message, if any.
-* `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
-
-A Promises/A+ promise is returned when `callback` is not provided.
-
-#### toBuffer([callback])
-
-Write image data to a Buffer, the format of which will match the input image by default. JPEG, PNG and WebP are supported.
-
-`callback`, if present, gets three arguments `(err, buffer, info)` where:
-
-* `err` is an error message, if any.
-* `buffer` is the output image data.
-* `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
-
-A Promises/A+ promise is returned when `callback` is not provided.
-
-#### jpeg()
-
-Use JPEG format for the output image.
-
-#### png()
-
-Use PNG format for the output image.
-
-#### webp()
-
-Use WebP format for the output image.
-
-#### raw()
-
-Provide raw, uncompressed uint8 (unsigned char) image data for Buffer and Stream based output.
-
-The number of channels depends on the input image and selected options.
-
-* 1 channel for images converted to `greyscale()`, with each byte representing one pixel.
-* 3 channels for colour images without alpha transparency, with bytes ordered \[red, green, blue, red, green, blue, etc.\]).
-* 4 channels for colour images with alpha transparency, with bytes ordered \[red, green, blue, alpha, red, green, blue, alpha, etc.\].
-
-#### toFormat(format)
-
-Convenience method for the above output format methods, where `format` is either:
-
-* an attribute of the `sharp.format` Object e.g. `sharp.format.jpeg`, or
-* a String containing `jpeg`, `png`, `webp` or `raw`.
-
-#### quality(quality)
-
-The output quality to use for lossy JPEG, WebP and TIFF output formats. The default quality is `80`.
-
-`quality` is a Number between 1 and 100.
-
-#### progressive()
-
-Use progressive (interlace) scan for JPEG and PNG output. This typically reduces compression performance by 30% but results in an image that can be rendered sooner when decompressed.
-
-#### withMetadata([metadata])
-
-Include all metadata (EXIF, XMP, IPTC) from the input image in the output image.
-This will also convert to and add the latest web-friendly v2 sRGB ICC profile.
-
-The optional `metadata` parameter, if present, is an Object with the attributes to update.
-New attributes cannot be inserted, only existing attributes updated.
-
-* `orientation` is an integral Number between 1 and 8, used to update the value of the EXIF `Orientation` tag.
-This has no effect if the input image does not have an EXIF `Orientation` tag.
-
-The default behaviour, when `withMetadata` is not used, is to strip all metadata and convert to the device-independent sRGB colour space.
-
-#### tile(options)
-
-The size, overlap, container and directory layout to use when generating square Deep Zoom image pyramid tiles.
-
-`options` is an Object with one or more of the following attributes:
-
-* `size` is an integral Number between 1 and 8192. The default value is 256 pixels.
-* `overlap` is an integral Number between 0 and 8192. The default value is 0 pixels.
-* `container` is a String, with value `fs` or `zip`. The default value is `fs`.
-* `layout` is a String, with value `dz`, `zoomify` or `google`. The default value is `dz`.
-
-You can also use the file extension .zip or .szi to write to a ZIP container instead of the filesystem.
-
-```javascript
-sharp('input.tiff')
-  .tile({
-    size: 512
-  })
-  .toFile('output.dzi', function(err, info) {
-    // output.dzi is the Deep Zoom XML definition
-    // output_files contains 512x512 tiles grouped by zoom level
-  });
-```
-
-#### withoutChromaSubsampling()
-
-Disable the use of [chroma subsampling](http://en.wikipedia.org/wiki/Chroma_subsampling) with JPEG output (4:4:4).
-
-This can improve colour representation at higher quality settings (90+),
-but usually increases output file size and typically reduces performance by 25%.
-
-The default behaviour is to use chroma subsampling (4:2:0).
-
-#### compressionLevel(compressionLevel)
-
-An advanced setting for the _zlib_ compression level of the lossless PNG output format. The default level is `6`.
-
-`compressionLevel` is a Number between 0 and 9.
-
-#### withoutAdaptiveFiltering()
-
-An advanced setting to disable adaptive row filtering for the lossless PNG output format.
-
-#### trellisQuantisation() / trellisQuantization()
-
-_Requires libvips to have been compiled with mozjpeg support_
-
-An advanced setting to apply the use of
-[trellis quantisation](http://en.wikipedia.org/wiki/Trellis_quantization) with JPEG output.
-Reduces file size and slightly increases relative quality at the cost of increased compression time.
-
-#### overshootDeringing()
-
-_Requires libvips to have been compiled with mozjpeg support_
-
-An advanced setting to reduce the effects of
-[ringing](http://en.wikipedia.org/wiki/Ringing_%28signal%29) in JPEG output,
-in particular where black text appears on a white background (or vice versa).
-
-#### optimiseScans() / optimizeScans()
-
-_Requires libvips to have been compiled with mozjpeg support_
-
-An advanced setting for progressive (interlace) JPEG output.
-Calculates which spectrum of DCT coefficients uses the fewest bits.
-Usually reduces file size at the cost of increased compression time.
-
-### Attributes
-
-#### format
-
-An Object containing nested boolean values
-representing the available input and output formats/methods,
-for example:
-
-```javascript
-> console.dir(sharp.format);
-
-{ jpeg: { id: 'jpeg',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: true, buffer: true, stream: true } },
-  png: { id: 'png',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: true, buffer: true, stream: true } },
-  webp: { id: 'webp',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: true, buffer: true, stream: true } },
-  tiff: { id: 'tiff',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: true, buffer: false, stream: false } },
-  magick: { id: 'magick',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: false, buffer: false, stream: false } },
-  raw: { id: 'raw',
-    input: { file: false, buffer: false, stream: false },
-    output: { file: false, buffer: true, stream: true } } }
-```
-
-#### queue
-
-An EventEmitter that emits a `change` event when a task is either:
-
-* queued, waiting for _libuv_ to provide a worker thread
-* complete
-
-```javascript
-sharp.queue.on('change', function(queueLength) {
-  console.log('Queue contains ' + queueLength + ' task(s)');
-});
-```
-
-#### versions
-
-An Object containing the version numbers of libvips and, on Linux, its dependencies.
-
-```javascript
-> console.log(sharp.versions);
-
-{ zlib: '1.2.8',
-  ffi: '3.2.1',
-  glib: '2.46.2',
-  xml: '2.9.2',
-  gsf: '1.14.34',
-  exif: '0.6.21',
-  jpeg: '1.4.2',
-  png: '1.6.19',
-  lcms: '2.7',
-  webp: '0.4.4',
-  tiff: '4.0.6',
-  magick: '6.9.2-6',
-  orc: '0.4.24',
-  vips: '8.1.1' }
-```
-
-### Utilities
-
-#### sharp.cache([options])
-
-If `options` is provided, sets the limits of _libvips'_ operation cache.
-
-* `options.memory` is the maximum memory in MB to use for this cache, with a default value of 50
-* `options.files` is the maximum number of files to hold open, with a default value of 20
-* `options.items` is the maximum number of operations to cache, with a default value of 100
-
-`options` can also be a boolean, where `true` enables the default cache settings and `false` disables all caching.
-
-This method always returns cache statistics, useful for determining how much working memory is required for a particular task.
-
-```javascript
-var stats = sharp.cache();
-```
-
-```javascript
-sharp.cache( { items: 200 } );
-sharp.cache( { files: 0 } );
-sharp.cache(false);
-```
-
-#### sharp.concurrency([threads])
-
-`threads`, if provided, is the Number of threads _libvips'_ should create for processing each image. The default value is the number of CPU cores. A value of `0` will reset to this default.
-
-This method always returns the current concurrency.
-
-```javascript
-var threads = sharp.concurrency(); // 4
-sharp.concurrency(2); // 2
-sharp.concurrency(0); // 4
-```
-
-The maximum number of images that can be processed in parallel is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
-
-#### sharp.counters()
-
-Provides access to internal task counters.
-
-* `queue` is the number of tasks this module has queued waiting for _libuv_ to provide a worker thread from its pool.
-* `process` is the number of resize tasks currently being processed.
-
-```javascript
-var counters = sharp.counters(); // { queue: 2, process: 4 }
-```
-
-#### sharp.simd([enable])
-
-_Requires libvips to have been compiled with liborc support_
-
-Improves the performance of `resize`, `blur` and `sharpen` operations
-by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM NEON.
-
-* `enable`, if present, is a boolean where `true` enables and `false` disables the use of SIMD.
-
-This method always returns the current state.
-
-This feature is currently disabled by default
-but future versions may enable it by default.
-
-When enabled, versions of liborc prior to 0.4.24
-and versions of libvips prior to 8.2.0
-have been known to crash under heavy load.
-
-```javascript
-var simd = sharp.simd();
-// simd is `true` if SIMD is currently enabled
-```
-
-```javascript
-var simd = sharp.simd(true);
-// attempts to enable the use of SIMD, returning true if available
-```

docs/changelog.md

@@ -1,5 +1,610 @@
 # Changelog
 
+### v0.21 - "*teeth*"
+
+Requires libvips v8.7.0.
+
+#### v0.21.2 - 13<sup>th</sup> January 2019
+
+* Ensure all metadata is removed from PNG output unless `withMetadata` used.
+
+* Ensure shortest edge is at least one pixel after resizing.
+  [#1003](https://github.com/lovell/sharp/issues/1003)
+
+* Add `ensureAlpha` operation to add an alpha channel, if missing.
+  [#1153](https://github.com/lovell/sharp/issues/1153)
+
+* Expose `pages` and `pageHeight` metadata for multi-page input images.
+  [#1205](https://github.com/lovell/sharp/issues/1205)
+
+* Expose PNG output options requiring libimagequant.
+  [#1484](https://github.com/lovell/sharp/issues/1484)
+
+* Expose underlying error message for invalid input.
+  [#1505](https://github.com/lovell/sharp/issues/1505)
+
+* Prevent mutatation of options passed to `jpeg`.
+  [#1516](https://github.com/lovell/sharp/issues/1516)
+
+* Ensure forced output format applied correctly when output chaining.
+  [#1528](https://github.com/lovell/sharp/issues/1528)
+
+#### v0.21.1 - 7<sup>th</sup> December 2018
+
+* Install: support `sharp_dist_base_url` npm config, like existing `SHARP_DIST_BASE_URL`.
+  [#1422](https://github.com/lovell/sharp/pull/1422)
+  [@SethWen](https://github.com/SethWen)
+
+* Ensure `channel` metadata is correct for raw, greyscale output.
+  [#1425](https://github.com/lovell/sharp/issues/1425)
+
+* Add support for the "mitchell" kernel for image reductions.
+  [#1438](https://github.com/lovell/sharp/pull/1438)
+  [@Daiz](https://github.com/Daiz)
+
+* Allow separate parameters for gamma encoding and decoding.
+  [#1439](https://github.com/lovell/sharp/pull/1439)
+  [@Daiz](https://github.com/Daiz)
+
+* Build prototype with `Object.assign` to allow minification.
+  [#1475](https://github.com/lovell/sharp/pull/1475)
+  [@jaubourg](https://github.com/jaubourg)
+
+* Expose libvips' recombination matrix operation.
+  [#1477](https://github.com/lovell/sharp/pull/1477)
+  [@fromkeith](https://github.com/fromkeith)
+
+* Expose libvips' pyramid/tile options for TIFF output.
+  [#1483](https://github.com/lovell/sharp/pull/1483)
+  [@mbklein](https://github.com/mbklein)
+
+#### v0.21.0 - 4<sup>th</sup> October 2018
+
+* Deprecate the following resize-related functions:
+    `crop`, `embed`, `ignoreAspectRatio`, `max`, `min` and `withoutEnlargement`.
+  Access to these is now via options passed to the `resize` function.
+  For example:
+    `embed('north')` is now `resize(width, height, { fit: 'contain', position: 'north' })`,
+    `crop('attention')` is now `resize(width, height, { fit: 'cover', position: 'attention' })`,
+    `max().withoutEnlargement()` is now `resize(width, height, { fit: 'inside', withoutEnlargement: true })`.
+  [#1135](https://github.com/lovell/sharp/issues/1135)
+
+* Deprecate the `background` function.
+    Per-operation `background` options added to `resize`, `extend` and `flatten` operations.
+  [#1392](https://github.com/lovell/sharp/issues/1392)
+
+* Add `size` to `metadata` response (Stream and Buffer input only).
+  [#695](https://github.com/lovell/sharp/issues/695)
+
+* Switch from custom trim operation to `vips_find_trim`.
+  [#914](https://github.com/lovell/sharp/issues/914)
+
+* Add `chromaSubsampling` and `isProgressive` properties to `metadata` response.
+  [#1186](https://github.com/lovell/sharp/issues/1186)
+
+* Drop Node 4 support.
+  [#1212](https://github.com/lovell/sharp/issues/1212)
+
+* Enable SIMD convolution by default.
+  [#1213](https://github.com/lovell/sharp/issues/1213)
+
+* Add experimental prebuilt binaries for musl-based Linux.
+  [#1379](https://github.com/lovell/sharp/issues/1379)
+
+* Add support for arbitrary rotation angle via vips_rotate.
+  [#1385](https://github.com/lovell/sharp/pull/1385)
+  [@freezy](https://github.com/freezy)
+
+### v0.20 - "*prebuild*"
+
+Requires libvips v8.6.1.
+
+#### v0.20.8 - 5<sup>th</sup> September 2018
+
+* Avoid race conditions when creating directories during installation.
+  [#1358](https://github.com/lovell/sharp/pull/1358)
+  [@ajhool](https://github.com/ajhool)
+
+* Accept floating point values for input density parameter.
+  [#1362](https://github.com/lovell/sharp/pull/1362)
+  [@aeirola](https://github.com/aeirola)
+
+#### v0.20.7 - 21<sup>st</sup> August 2018
+
+* Use copy+unlink if rename operation fails during installation.
+  [#1345](https://github.com/lovell/sharp/issues/1345)
+
+#### v0.20.6 - 20<sup>th</sup> August 2018
+
+* Add removeAlpha operation to remove alpha channel, if any.
+  [#1248](https://github.com/lovell/sharp/issues/1248)
+
+* Expose mozjpeg quant_table flag.
+  [#1285](https://github.com/lovell/sharp/pull/1285)
+  [@rexxars](https://github.com/rexxars)
+
+* Allow full WebP alphaQuality range of 0-100.
+  [#1290](https://github.com/lovell/sharp/pull/1290)
+  [@sylvaindumont](https://github.com/sylvaindumont)
+
+* Cache libvips binaries to reduce re-install time.
+  [#1301](https://github.com/lovell/sharp/issues/1301)
+
+* Ensure vendor platform mismatch throws error at install time.
+  [#1303](https://github.com/lovell/sharp/issues/1303)
+
+* Improve install time error messages for FreeBSD users.
+  [#1310](https://github.com/lovell/sharp/issues/1310)
+
+* Ensure extractChannel works with 16-bit images.
+  [#1330](https://github.com/lovell/sharp/issues/1330)
+
+* Expose depth option for tile-based output.
+  [#1342](https://github.com/lovell/sharp/pull/1342)
+  [@alundavies](https://github.com/alundavies)
+
+* Add experimental entropy field to stats response.
+
+#### v0.20.5 - 27<sup>th</sup> June 2018
+
+* Expose libjpeg optimize_coding flag.
+  [#1265](https://github.com/lovell/sharp/pull/1265)
+  [@tomlokhorst](https://github.com/tomlokhorst)
+
+#### v0.20.4 - 20<sup>th</sup> June 2018
+
+* Prevent possible rounding error when using shrink-on-load and 90/270 degree rotation.
+  [#1241](https://github.com/lovell/sharp/issues/1241)
+  [@anahit42](https://github.com/anahit42)
+
+* Ensure extractChannel sets correct single-channel colour space interpretation.
+  [#1257](https://github.com/lovell/sharp/issues/1257)
+  [@jeremychone](https://github.com/jeremychone)
+
+#### v0.20.3 - 29<sup>th</sup> May 2018
+
+* Fix tint operation by ensuring LAB interpretation and allowing negative values.
+  [#1235](https://github.com/lovell/sharp/issues/1235)
+  [@wezside](https://github.com/wezside)
+
+#### v0.20.2 - 28<sup>th</sup> April 2018
+
+* Add tint operation to set image chroma.
+  [#825](https://github.com/lovell/sharp/pull/825)
+  [@rikh42](https://github.com/rikh42)
+
+* Add environment variable to ignore globally-installed libvips.
+  [#1165](https://github.com/lovell/sharp/pull/1165)
+  [@oncletom](https://github.com/oncletom)
+
+* Add support for page selection with multi-page input (GIF/TIFF).
+  [#1204](https://github.com/lovell/sharp/pull/1204)
+  [@woolite64](https://github.com/woolite64)
+
+* Add support for Group4 (CCITTFAX4) compression with TIFF output.
+  [#1208](https://github.com/lovell/sharp/pull/1208)
+  [@woolite64](https://github.com/woolite64)
+
+#### v0.20.1 - 17<sup>th</sup> March 2018
+
+* Improve installation experience when a globally-installed libvips below the minimum required version is found.
+  [#1148](https://github.com/lovell/sharp/issues/1148)
+
+* Prevent smartcrop error when cumulative rounding is below target size.
+  [#1154](https://github.com/lovell/sharp/issues/1154)
+  [@ralrom](https://github.com/ralrom)
+
+* Expose libvips' median filter operation.
+  [#1161](https://github.com/lovell/sharp/pull/1161)
+  [@BiancoA](https://github.com/BiancoA)
+
+#### v0.20.0 - 5<sup>th</sup> March 2018
+
+* Add support for prebuilt sharp binaries on common platforms.
+  [#186](https://github.com/lovell/sharp/issues/186)
+
+### v0.19 - "*suit*"
+
+Requires libvips v8.6.1.
+
+#### v0.19.1 - 24<sup>th</sup> February 2018
+
+* Expose libvips' linear transform feature.
+  [#1024](https://github.com/lovell/sharp/pull/1024)
+  [@3epnm](https://github.com/3epnm)
+
+* Expose angle option for tile-based output.
+  [#1121](https://github.com/lovell/sharp/pull/1121)
+  [@BiancoA](https://github.com/BiancoA)
+
+* Prevent crop operation when image already at or below target dimensions.
+  [#1134](https://github.com/lovell/sharp/issues/1134)
+  [@pieh](https://github.com/pieh)
+
+#### v0.19.0 - 11<sup>th</sup> January 2018
+
+* Expose offset coordinates of strategy-based crop.
+  [#868](https://github.com/lovell/sharp/issues/868)
+  [@mirohristov-com](https://github.com/mirohristov-com)
+
+* PNG output now defaults to adaptiveFiltering=false, compressionLevel=9
+  [#872](https://github.com/lovell/sharp/issues/872)
+  [@wmertens](https://github.com/wmertens)
+
+* Add stats feature for pixel-derived image statistics.
+  [#915](https://github.com/lovell/sharp/pull/915)
+  [@rnanwani](https://github.com/rnanwani)
+
+* Add failOnError option to fail-fast on bad input image data.
+  [#976](https://github.com/lovell/sharp/pull/976)
+  [@mceachen](https://github.com/mceachen)
+
+* Resize: switch to libvips' implementation, make fastShrinkOnLoad optional, remove interpolator and centreSampling options.
+  [#977](https://github.com/lovell/sharp/pull/977)
+  [@jardakotesovec](https://github.com/jardakotesovec)
+
+* Attach finish event listener to a clone only for Stream-based input.
+  [#995](https://github.com/lovell/sharp/issues/995)
+  [@whmountains](https://github.com/whmountains)
+
+* Add tilecache before smartcrop to avoid over-computation of previous operations.
+  [#1028](https://github.com/lovell/sharp/issues/1028)
+  [@coffeebite](https://github.com/coffeebite)
+
+* Prevent toFile extension taking precedence over requested format.
+  [#1037](https://github.com/lovell/sharp/issues/1037)
+  [@tomgallagher](https://github.com/tomgallagher)
+
+* Add support for gravity option to existing embed feature.
+  [#1038](https://github.com/lovell/sharp/pull/1038)
+  [@AzureByte](https://github.com/AzureByte)
+
+* Expose IPTC and XMP metadata when available.
+  [#1079](https://github.com/lovell/sharp/pull/1079)
+  [@oaleynik](https://github.com/oaleynik)
+
+* TIFF output: switch default predictor from 'none' to 'horizontal' to match libvips' behaviour.
+
+### v0.18 - "*ridge*"
+
+Requires libvips v8.5.5.
+
+#### v0.18.4 - 18<sup>th</sup> September 2017
+
+* Ensure input Buffer really is marked as Persistent, prevents mark-sweep GC.
+  [#950](https://github.com/lovell/sharp/issues/950)
+  [@lfdoherty](https://github.com/lfdoherty)
+
+#### v0.18.3 - 13<sup>th</sup> September 2017
+
+* Skip shrink-on-load when trimming.
+  [#888](https://github.com/lovell/sharp/pull/888)
+  [@kleisauke](https://github.com/kleisauke)
+
+* Migrate from got to simple-get for basic auth support.
+  [#945](https://github.com/lovell/sharp/pull/945)
+  [@pbomb](https://github.com/pbomb)
+
+#### v0.18.2 - 1<sup>st</sup> July 2017
+
+* Expose libvips' xres and yres properties for TIFF output.
+  [#828](https://github.com/lovell/sharp/pull/828)
+  [@YvesBos](https://github.com/YvesBos)
+
+* Ensure flip and flop operations work with auto-rotate.
+  [#837](https://github.com/lovell/sharp/issues/837)
+  [@rexxars](https://github.com/rexxars)
+
+* Allow binary download URL override via SHARP_DIST_BASE_URL env variable.
+  [#841](https://github.com/lovell/sharp/issues/841)
+
+* Add support for Solus Linux.
+  [#857](https://github.com/lovell/sharp/pull/857)
+  [@ekremkaraca](https://github.com/ekremkaraca)
+
+#### v0.18.1 - 30<sup>th</sup> May 2017
+
+* Remove regression from #781 that could cause incorrect shrink calculation.
+  [#831](https://github.com/lovell/sharp/issues/831)
+  [@suprMax](https://github.com/suprMax)
+
+#### v0.18.0 - 30<sup>th</sup> May 2017
+
+* Remove the previously-deprecated output format "option" functions:
+    quality, progressive, compressionLevel, withoutAdaptiveFiltering,
+    withoutChromaSubsampling, trellisQuantisation, trellisQuantization,
+    overshootDeringing, optimiseScans and optimizeScans.
+
+* Ensure maximum output dimensions are based on the format to be used.
+  [#176](https://github.com/lovell/sharp/issues/176)
+  [@stephanebachelier](https://github.com/stephanebachelier)
+
+* Avoid costly (un)premultiply when using overlayWith without alpha channel.
+  [#573](https://github.com/lovell/sharp/issues/573)
+  [@strarsis](https://github.com/strarsis)
+
+* Include pixel depth (e.g. "uchar") when reading metadata.
+  [#577](https://github.com/lovell/sharp/issues/577)
+  [@moedusa](https://github.com/moedusa)
+
+* Add support for Buffer and Stream-based TIFF output.
+  [#587](https://github.com/lovell/sharp/issues/587)
+  [@strarsis](https://github.com/strarsis)
+
+* Expose warnings from libvips via NODE_DEBUG=sharp environment variable.
+  [#607](https://github.com/lovell/sharp/issues/607)
+  [@puzrin](https://github.com/puzrin)
+
+* Switch to the libvips implementation of "attention" and "entropy" crop strategies.
+  [#727](https://github.com/lovell/sharp/issues/727)
+
+* Improve performance and accuracy of nearest neighbour integral upsampling.
+  [#752](https://github.com/lovell/sharp/issues/752)
+  [@MrIbby](https://github.com/MrIbby)
+
+* Constructor single argument API: allow plain object, reject null/undefined.
+  [#768](https://github.com/lovell/sharp/issues/768)
+  [@kub1x](https://github.com/kub1x)
+
+* Ensure ARM64 pre-built binaries use correct C++11 ABI version.
+  [#772](https://github.com/lovell/sharp/issues/772)
+  [@ajiratech2](https://github.com/ajiratech2)
+
+* Prevent aliasing by using dynamic values for shrink(-on-load).
+  [#781](https://github.com/lovell/sharp/issues/781)
+  [@kleisauke](https://github.com/kleisauke)
+
+* Expose libvips' "squash" parameter to enable 1-bit TIFF output.
+  [#783](https://github.com/lovell/sharp/pull/783)
+  [@YvesBos](https://github.com/YvesBos)
+
+* Add support for rotation using any multiple of +/-90 degrees.
+  [#791](https://github.com/lovell/sharp/pull/791)
+  [@ncoden](https://github.com/ncoden)
+
+* Add "jpg" alias to toFormat as shortened form of "jpeg".
+  [#814](https://github.com/lovell/sharp/pull/814)
+  [@jingsam](https://github.com/jingsam)
+
+### v0.17 - "*quill*"
+
+Requires libvips v8.4.2.
+
+#### v0.17.3 - 1<sup>st</sup> April 2017
+
+* Allow toBuffer to optionally resolve a Promise with both info and data.
+  [#143](https://github.com/lovell/sharp/issues/143)
+  [@salzhrani](https://github.com/salzhrani)
+
+* Create blank image of given width, height, channels and background.
+  [#470](https://github.com/lovell/sharp/issues/470)
+  [@pjarts](https://github.com/pjarts)
+
+* Add support for the "nearest" kernel for image reductions.
+  [#732](https://github.com/lovell/sharp/pull/732)
+  [@alice0meta](https://github.com/alice0meta)
+
+* Add support for TIFF compression and predictor options.
+  [#738](https://github.com/lovell/sharp/pull/738)
+  [@kristojorg](https://github.com/kristojorg)
+
+#### v0.17.2 - 11<sup>th</sup> February 2017
+
+* Ensure Readable side of Stream can start flowing after Writable side has finished.
+  [#671](https://github.com/lovell/sharp/issues/671)
+  [@danhaller](https://github.com/danhaller)
+
+* Expose WebP alpha quality, lossless and near-lossless output options.
+  [#685](https://github.com/lovell/sharp/pull/685)
+  [@rnanwani](https://github.com/rnanwani)
+
+#### v0.17.1 - 15<sup>th</sup> January 2017
+
+* Improve error messages for invalid parameters.
+  [@spikeon](https://github.com/spikeon)
+  [#644](https://github.com/lovell/sharp/pull/644)
+
+* Simplify expression for finding vips-cpp libdir.
+  [#656](https://github.com/lovell/sharp/pull/656)
+
+* Allow HTTPS-over-HTTP proxy when downloading pre-compiled dependencies.
+  [@wangzhiwei1888](https://github.com/wangzhiwei1888)
+  [#679](https://github.com/lovell/sharp/issues/679)
+
+#### v0.17.0 - 11<sup>th</sup> December 2016
+
+* Drop support for versions of Node prior to v4.
+
+* Deprecate the following output format "option" functions:
+    quality, progressive, compressionLevel, withoutAdaptiveFiltering,
+    withoutChromaSubsampling, trellisQuantisation, trellisQuantization,
+    overshootDeringing, optimiseScans and optimizeScans.
+  Access to these is now via output format functions, for example `quality(n)`
+    is now `jpeg({quality: n})` and/or `webp({quality: n})`.
+
+* Autoconvert GIF and SVG input to PNG output if no other format is specified.
+
+* Expose libvips' "centre" resize option to mimic \*magick's +0.5px convention.
+  [#568](https://github.com/lovell/sharp/issues/568)
+
+* Ensure support for embedded base64 PNG and JPEG images within an SVG.
+  [#601](https://github.com/lovell/sharp/issues/601)
+  [@dynamite-ready](https://github.com/dynamite-ready)
+
+* Ensure premultiply operation occurs before box filter shrink.
+  [#605](https://github.com/lovell/sharp/issues/605)
+  [@CmdrShepardsPie](https://github.com/CmdrShepardsPie)
+  [@teroparvinen](https://github.com/teroparvinen)
+
+* Add support for PNG and WebP tile-based output formats (in addition to JPEG).
+  [#622](https://github.com/lovell/sharp/pull/622)
+  [@ppaskaris](https://github.com/ppaskaris)
+
+* Allow use of extend with greyscale input.
+  [#623](https://github.com/lovell/sharp/pull/623)
+  [@ppaskaris](https://github.com/ppaskaris)
+
+* Allow non-RGB input to embed/extend onto background with an alpha channel.
+  [#646](https://github.com/lovell/sharp/issues/646)
+  [@DaGaMs](https://github.com/DaGaMs)
+
+### v0.16 - "*pencil*"
+
+Requires libvips v8.3.3
+
+#### v0.16.2 - 22<sup>nd</sup> October 2016
+
+* Restrict readelf usage to Linux only when detecting global libvips version.
+  [#602](https://github.com/lovell/sharp/issues/602)
+  [@caoko](https://github.com/caoko)
+
+#### v0.16.1 - 13<sup>th</sup> October 2016
+
+* C++11 ABI version is now auto-detected, remove sharp-cxx11 installation flag.
+
+* Add experimental 'attention' crop strategy.
+  [#295](https://github.com/lovell/sharp/issues/295)
+
+* Include .node extension for Meteor's require() implementation.
+  [#537](https://github.com/lovell/sharp/issues/537)
+  [@isjackwild](https://github.com/isjackwild)
+
+* Ensure convolution kernel scale is clamped to a minimum value of 1.
+  [#561](https://github.com/lovell/sharp/issues/561)
+  [@abagshaw](https://github.com/abagshaw)
+
+* Correct calculation of y-axis placement when overlaying image at a fixed point.
+  [#566](https://github.com/lovell/sharp/issues/566)
+  [@Nateowami](https://github.com/Nateowami)
+
+#### v0.16.0 - 18<sup>th</sup> August 2016
+
+* Add pre-compiled libvips for OS X, ARMv7 and ARMv8.
+  [#312](https://github.com/lovell/sharp/issues/312)
+
+* Ensure boolean, bandbool, extractChannel ops occur before sRGB conversion.
+  [#504](https://github.com/lovell/sharp/pull/504)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Recalculate factors after WebP shrink-on-load to avoid round-to-zero errors.
+  [#508](https://github.com/lovell/sharp/issues/508)
+  [@asilvas](https://github.com/asilvas)
+
+* Prevent boolean errors during extract operation.
+  [#511](https://github.com/lovell/sharp/pull/511)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Add joinChannel and toColourspace/toColorspace operations.
+  [#513](https://github.com/lovell/sharp/pull/513)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Add support for raw pixel data with boolean and withOverlay operations.
+  [#516](https://github.com/lovell/sharp/pull/516)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Prevent bandbool creating a single channel sRGB image.
+  [#519](https://github.com/lovell/sharp/pull/519)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Ensure ICC profiles are removed from PNG output unless withMetadata used.
+  [#521](https://github.com/lovell/sharp/issues/521)
+  [@ChrisPinewood](https://github.com/ChrisPinewood)
+
+* Add alpha channels, if missing, to overlayWith images.
+  [#540](https://github.com/lovell/sharp/pull/540)
+  [@cmtt](https://github.com/cmtt)
+
+* Remove deprecated interpolateWith method - use resize(w, h, { interpolator: ... })
+  [#310](https://github.com/lovell/sharp/issues/310)
+
+### v0.15 - "*outfit*"
+
+Requires libvips v8.3.1
+
+#### v0.15.1 - 12<sup>th</sup> July 2016
+
+* Concat Stream-based input in single operation for ~+3% perf and less GC.
+  [#429](https://github.com/lovell/sharp/issues/429)
+  [@papandreou](https://github.com/papandreou)
+
+* Add alpha channel, if required, before extend operation.
+  [#439](https://github.com/lovell/sharp/pull/439)
+  [@frulo](https://github.com/frulo)
+
+* Allow overlay image to be repeated across entire image via tile option.
+  [#443](https://github.com/lovell/sharp/pull/443)
+  [@lemnisk8](https://github.com/lemnisk8)
+
+* Add cutout option to overlayWith feature, applies only the alpha channel of the overlay image.
+  [#448](https://github.com/lovell/sharp/pull/448)
+  [@kleisauke](https://github.com/kleisauke)
+
+* Ensure scaling factors are calculated independently to prevent rounding errors.
+  [#452](https://github.com/lovell/sharp/issues/452)
+  [@puzrin](https://github.com/puzrin)
+
+* Add --sharp-cxx11 flag to compile with gcc's new C++11 ABI.
+  [#456](https://github.com/lovell/sharp/pull/456)
+  [@kapouer](https://github.com/kapouer)
+
+* Add top/left offset support to overlayWith operation.
+  [#473](https://github.com/lovell/sharp/pull/473)
+  [@rnanwani](https://github.com/rnanwani)
+
+* Add convolve operation for kernel-based convolution.
+  [#479](https://github.com/lovell/sharp/pull/479)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Add greyscale option to threshold operation for colourspace conversion control.
+  [#480](https://github.com/lovell/sharp/pull/480)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Ensure ICC profiles are licenced for distribution.
+  [#486](https://github.com/lovell/sharp/issues/486)
+  [@kapouer](https://github.com/kapouer)
+
+* Allow images with an alpha channel to work with LAB-colourspace based sharpen.
+  [#490](https://github.com/lovell/sharp/issues/490)
+  [@jwagner](https://github.com/jwagner)
+
+* Add trim operation to remove "boring" edges.
+  [#492](https://github.com/lovell/sharp/pull/492)
+  [@kleisauke](https://github.com/kleisauke)
+
+* Add bandbool feature for channel-wise boolean operations.
+  [#496](https://github.com/lovell/sharp/pull/496)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Add extractChannel operation to extract a channel from an image.
+  [#497](https://github.com/lovell/sharp/pull/497)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Add ability to read and write native libvips .v files.
+  [#500](https://github.com/lovell/sharp/pull/500)
+  [@mhirsch](https://github.com/mhirsch)
+
+* Add boolean feature for bitwise image operations.
+  [#501](https://github.com/lovell/sharp/pull/501)
+  [@mhirsch](https://github.com/mhirsch)
+
+#### v0.15.0 - 21<sup>st</sup> May 2016
+
+* Use libvips' new Lanczos 3 kernel as default for image reduction.
+  Deprecate interpolateWith method, now provided as a resize option.
+  [#310](https://github.com/lovell/sharp/issues/310)
+  [@jcupitt](https://github.com/jcupitt)
+
+* Take advantage of libvips v8.3 features.
+  Add support for libvips' new GIF and SVG loaders.
+  Pre-built binaries now include giflib and librsvg, exclude *magick.
+  Use shrink-on-load for WebP input.
+  Break existing sharpen API to accept sigma and improve precision.
+  [#369](https://github.com/lovell/sharp/issues/369)
+
+* Remove unnecessary (un)premultiply operations when not resizing/compositing.
+  [#413](https://github.com/lovell/sharp/issues/413)
+  [@jardakotesovec](https://github.com/jardakotesovec)
+
 ### v0.14 - "*needle*"
 
 Requires libvips v8.2.3
@@ -62,6 +667,9 @@ Requires libvips v8.2.3
   [#387](https://github.com/lovell/sharp/issues/387)
   [@kleisauke](https://github.com/kleisauke)
 
+* Remove deprecated style of calling extract API. Breaks calls using positional arguments.
+  [#276](https://github.com/lovell/sharp/issues/276)
+
 ### v0.13 - "*mind*"
 
 Requires libvips v8.2.2

docs/css/extra.css

@@ -0,0 +1,5 @@
+/* Nest document subheadings in navigation */
+ul.subnav ul:not(.subnav) {
+  padding-left: 2em;
+  font-size: 80%;
+}

docs/image/sharp-logo.svg

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="86 86 550 550">
+<!-- Copyright 2019 Lovell Fuller. This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) License. -->
+<path fill="none" stroke="#9c0" stroke-width="80" d="M258.411 285.777l200.176-26.8M244.113 466.413L451.44 438.66M451.441 438.66V238.484M451.441 88.363v171.572l178.725-23.917M270.323 255.602V477.22M272.71 634.17V462.591L93.984 486.515"/>
+<path fill="none" stroke="#090" stroke-width="80" d="M451.441 610.246V438.66l178.725-23.91M269.688 112.59v171.58L90.964 308.093"/>
+</svg>

docs/index.md

@@ -1,32 +1,31 @@
 # sharp
 
+<img src="image/sharp-logo.svg" width="160" height="160" alt="sharp logo" align="right">
+
 The typical use case for this high speed Node.js module
-is to convert large images of many formats to
+is to convert large images in common formats to
 smaller, web-friendly JPEG, PNG and WebP images of varying dimensions.
 
-Resizing an image is typically 4x faster than using the
+Resizing an image is typically 4x-5x faster than using the
 quickest ImageMagick and GraphicsMagick settings.
 
 Colour spaces, embedded ICC profiles and alpha transparency channels are all handled correctly.
-Bicubic interpolation with Lanczos anti-alias filtering ensures quality is not sacrificed for speed.
+Lanczos resampling ensures quality is not sacrificed for speed.
 
 As well as image resizing, operations such as
 rotation, extraction, compositing and gamma correction are available.
 
-Most Windows (x64), Linux and ARMv6+ systems do not require
+Most modern 64-bit OS X, Windows and Linux systems running
-the installation of any external runtime dependencies.
+Node versions 6, 8 and 10
-
+do not require any additional install or runtime dependencies.
-Use with OS X is as simple as running `brew install homebrew/science/vips`
-to install the libvips dependency.
 
 [![Test Coverage](https://coveralls.io/repos/lovell/sharp/badge.png?branch=master)](https://coveralls.io/r/lovell/sharp?branch=master)
 
 ### Formats
 
-This module supports reading JPEG, PNG, WebP, TIFF, OpenSlide,
+This module supports reading JPEG, PNG, WebP, TIFF, GIF and SVG images.
-GIF and most other libmagick-supported formats.
 
-Output images can be in JPEG, PNG and WebP formats as well as uncompressed raw pixel data.
+Output images can be in JPEG, PNG, WebP and TIFF formats as well as uncompressed raw pixel data.
 
 Streams, Buffer objects and the filesystem can be used for input and output.
 
@@ -40,7 +39,7 @@ and [Leaflet](https://github.com/turban/Leaflet.Zoomify).
 ### Fast
 
 This module is powered by the blazingly fast
-[libvips](https://github.com/jcupitt/libvips) image processing library,
+[libvips](https://github.com/libvips/libvips) image processing library,
 originally created in 1989 at Birkbeck College
 and currently maintained by
 [John Cupitt](https://github.com/jcupitt).
@@ -50,7 +49,7 @@ are held in memory and processed at a time,
 taking full advantage of multiple CPU cores and L1/L2/L3 cache.
 
 Everything remains non-blocking thanks to _libuv_,
-no child processes are spawned and Promises/A+ are supported.
+no child processes are spawned and Promises/async/await are supported.
 
 ### Optimal
 
@@ -59,9 +58,9 @@ without having to use separate command line tools like
 [jpegoptim](https://github.com/tjko/jpegoptim) and
 [jpegtran](http://jpegclub.org/jpegtran/).
 
-PNG filtering can be disabled,
+PNG filtering is disabled by default,
 which for diagrams and line art often produces the same result
-as [pngcrush](http://pmt.sourceforge.net/pngcrush/).
+as [pngcrush](https://pmt.sourceforge.io/pngcrush/).
 
 ### Contributing
 
@@ -89,17 +88,53 @@ the help and code contributions of the following people:
 * [Alaric Holloway](https://github.com/skedastik)
 * [Bernhard K. Weisshuhn](https://github.com/bkw)
 * [David A. Carley](https://github.com/dacarley)
+* [John Tobin](https://github.com/jtobinisaniceguy)
+* [Kenton Gray](https://github.com/kentongray)
+* [Felix Bünemann](https://github.com/felixbuenemann)
+* [Samy Al Zahrani](https://github.com/salzhrani)
+* [Chintan Thakkar](https://github.com/lemnisk8)
+* [F. Orlando Galashan](https://github.com/frulo)
+* [Kleis Auke Wolthuizen](https://github.com/kleisauke)
+* [Matt Hirsch](https://github.com/mhirsch)
+* [Rahul Nanwani](https://github.com/rnanwani)
+* [Matthias Thoemmes](https://github.com/cmtt)
+* [Patrick Paskaris](https://github.com/ppaskaris)
+* [Jérémy Lal](https://github.com/kapouer)
+* [Alice Monday](https://github.com/alice0meta)
+* [Kristo Jorgenson](https://github.com/kristojorg)
+* [Yves Bos](https://github.com/YvesBos)
+* [Nicolas Coden](https://github.com/ncoden)
+* [Matt Parrish](https://github.com/pbomb)
+* [Matthew McEachen](https://github.com/mceachen)
+* [Jarda Kotěšovec](https://github.com/jardakotesovec)
+* [Kenric D'Souza](https://github.com/AzureByte)
+* [Oleh Aleinyk](https://github.com/oaleynik)
+* [Marcel Bretschneider](https://github.com/3epnm)
+* [Andrea Bianco](https://github.com/BiancoA)
+* [Rik Heywood](https://github.com/rikh42)
+* [Thomas Parisot](https://github.com/oncletom)
+* [Nathan Graves](https://github.com/woolite64)
+* [Tom Lokhorst](https://github.com/tomlokhorst)
+* [Espen Hovlandsdal](https://github.com/rexxars)
+* [Sylvain Dumont](https://github.com/sylvaindumont)
+* [Alun Davies](https://github.com/alundavies)
+* [Aidan Hoolachan](https://github.com/ajhool)
+* [Axel Eirola](https://github.com/aeirola)
+* [Freezy](https://github.com/freezy)
+* [Julian Aubourg](https://github.com/jaubourg)
+* [Keith Belovay](https://github.com/fromkeith)
+* [Michael B. Klein](https://github.com/mbklein)
 
 Thank you!
 
-### Licence
+### Licensing
 
-Copyright 2013, 2014, 2015 Lovell Fuller and contributors.
+Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
-[http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0.html)
+[https://www.apache.org/licenses/LICENSE-2.0](https://www.apache.org/licenses/LICENSE-2.0)
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,

docs/install.md

@@ -4,111 +4,125 @@
 npm install sharp
 ```
 
-### Prerequisites
+```sh
+yarn add sharp
+```
 
-* C++11 compatible compiler such as gcc 4.6+ (Node v4+ requires gcc 4.8+), clang 3.0+ or MSVC 2013
+## Prerequisites
-* [node-gyp](https://github.com/TooTallNate/node-gyp#installation)
+
+* Node v4.5.0+
+
+### Building from source
+
+Pre-compiled binaries for sharp are provided for use with
+Node versions 6, 8, 10 and 11 on
+64-bit Windows, OS X and Linux platforms.
+
+Sharp will be built from source at install time when:
+
+* a globally-installed libvips is detected,
+* pre-compiled binaries do not exist for the current platform and Node version, or
+* when the `npm install --build-from-source` flag is used.
+
+Building from source requires:
+
+* C++11 compatible compiler such as gcc 4.8+, clang 3.0+ or MSVC 2013+
+* [node-gyp](https://github.com/nodejs/node-gyp#installation) and its dependencies (includes Python 2.7)
+
+## libvips
 
 ### Linux
 
-[![Ubuntu 14.04 Build Status](https://travis-ci.org/lovell/sharp.png?branch=master)](https://travis-ci.org/lovell/sharp)
+[![Ubuntu 16.04 Build Status](https://travis-ci.org/lovell/sharp.png?branch=master)](https://travis-ci.org/lovell/sharp)
-[![Linux Build Status](https://circleci.com/gh/lovell/sharp.svg?style=svg&circle-token=6cb6d1d287a51af83722b19ed8885377fbc85e5c)](https://circleci.com/gh/lovell/sharp)
 
-libvips and its dependencies are fetched and stored within `node_modules/sharp/lib` during `npm install`.
+libvips and its dependencies are fetched and stored within `node_modules/sharp/vendor` during `npm install`.
-This involves an automated HTTPS download of approximately 6MB.
+This involves an automated HTTPS download of approximately 8MB.
 
-Most recent Linux-based operating systems with glibc running on x64 and ARMv6+ CPUs should "just work", e.g.:
+Most Linux-based (glibc, musl) operating systems running on x64 and ARMv6+ CPUs should "just work", e.g.:
 
-* Debian 7, 8
+* Debian 7+
-* Ubuntu 12.04, 14.04, 14.10, 15.04, 15.10
+* Ubuntu 14.04+
-* Centos 7
+* Centos 7+
-* Fedora 21, 22, 23
+* Alpine 3.8+ (Node 8 and 10)
-* openSUSE 13.2
+* Fedora
-* Archlinux 2015.06.01
+* openSUSE 13.2+
+* Archlinux
 * Raspbian Jessie
-* Amazon Linux 2015.03, 2015.09
+* Amazon Linux
+* Solus
 
-To use your own version of libvips instead of the provided binaries, make sure it is
+To use a globally-installed version of libvips instead of the provided binaries,
-at least the version listed under `config.libvips` in the `package.json` file that it
+make sure it is at least the version listed under `config.libvips` in the `package.json` file
-can be located using `pkg-config`. If you are using non-stadard paths (anything other
+and that it can be located using `pkg-config --modversion vips-cpp`.
-than `/usr` or `/usr/local`), you might need to set `PKG_CONFIG_PATH` during `npm install`
+
+If you are using non-standard paths (anything other than `/usr` or `/usr/local`),
+you might need to set `PKG_CONFIG_PATH` during `npm install`
 and `LD_LIBRARY_PATH` at runtime.
 
-You can print the detected vips version using: `pkg-config --modversion vips-cpp`
-
 This allows the use of newer versions of libvips with older versions of sharp.
 
-For older Linux-based operating systems and 32-bit Intel CPUs,
+For 32-bit Intel CPUs and older Linux-based operating systems such as Centos 6,
-a system-wide installation of the most suitable version of
+compiling libvips from source is recommended.
-libvips and its dependencies can be achieved by running
+
-the following command as a user with `sudo` access
+[https://libvips.github.io/libvips/install.html#building-libvips-from-a-source-tarball](https://libvips.github.io/libvips/install.html#building-libvips-from-a-source-tarball)
-(requires `curl` and `pkg-config`):
+
+#### Alpine Linux
+
+libvips is available in the
+[testing repository](https://pkgs.alpinelinux.org/packages?name=vips-dev):
 
 ```sh
-curl -s https://raw.githubusercontent.com/lovell/sharp/master/preinstall.sh | sudo bash -
+apk add vips-dev fftw-dev build-base --update-cache \
+    --repository https://alpine.global.ssl.fastly.net/alpine/edge/testing/ \
+    --repository https://alpine.global.ssl.fastly.net/alpine/edge/main
 ```
 
-For Linux-based operating systems such as Alpine that use musl libc,
+The smaller stack size of musl libc means
-the smaller stack size means libvips' cache should be disabled
+libvips may need to be used without a cache
 via `sharp.cache(false)` to avoid a stack overflow.
 
-Beware of Linux OS upgrades that introduce v5.1+ of the `g++` compiler due to
-[changes](https://gcc.gnu.org/onlinedocs/libstdc++/manual/using_dual_abi.html)
-in the C++11 ABI.
-This module assumes the previous behaviour, which can be enforced by setting the
-`_GLIBCXX_USE_CXX11_ABI=0` environment variable at libvips' compile time.
-
 ### Mac OS
 
-[![OS X 10.9.5 Build Status](https://travis-ci.org/lovell/sharp.png?branch=master)](https://travis-ci.org/lovell/sharp)
+[![OS X 10.12 Build Status](https://travis-ci.org/lovell/sharp.png?branch=master)](https://travis-ci.org/lovell/sharp)
 
-libvips must be installed before `npm install` is run.
+libvips and its dependencies are fetched and stored within `node_modules/sharp/vendor` during `npm install`.
-This can be achieved via homebrew:
+This involves an automated HTTPS download of approximately 7MB.
 
-```sh
+To use your own version of libvips instead of the provided binaries, make sure it is
-brew install homebrew/science/vips
+at least the version listed under `config.libvips` in the `package.json` file and
-```
+that it can be located using `pkg-config --modversion vips-cpp`.
 
-For GIF input and WebP output suppport use:
+### Windows x64
-
-```sh
-brew install homebrew/science/vips --with-imagemagick --with-webp
-```
-
-A missing or incorrectly configured _Xcode Command Line Tools_ installation
-[can lead](https://github.com/lovell/sharp/issues/80) to a
-`library not found for -ljpeg` error.
-If so, please try: `xcode-select --install`.
-
-The _gettext_ dependency of _libvips_
-[can lead](https://github.com/lovell/sharp/issues/9)
-to a `library not found for -lintl` error.
-If so, please try `brew link gettext --force`.
-
-### Windows
 
 [![Windows x64 Build Status](https://ci.appveyor.com/api/projects/status/pgtul704nkhhg6sg)](https://ci.appveyor.com/project/lovell/sharp)
 
-libvips and its dependencies are fetched and stored within `node_modules\sharp` during `npm install`.
+libvips and its dependencies are fetched and stored within `node_modules\sharp\vendor` during `npm install`.
-This involves an automated HTTPS download of approximately 9MB.
+This involves an automated HTTPS download of approximately 13MB.  If you are having issues during
+installation consider removing the directory ```C:\Users\[user]\AppData\Roaming\npm-cache\_libvips```.
 
 Only 64-bit (x64) `node.exe` is supported.
-The WebP format is currently unavailable on Windows.
 
 ### FreeBSD
 
 libvips must be installed before `npm install` is run.
-This can be achieved via [FreshPorts](https://www.freshports.org/graphics/vips/):
+
+This can be achieved via package or ports:
+
+```sh
+pkg install -y pkgconf vips
+```
 
 ```sh
 cd /usr/ports/graphics/vips/ && make install clean
 ```
 
+FreeBSD's gcc v4 and v5 need `CXXFLAGS=-D_GLIBCXX_USE_C99` set for C++11 support due to
+https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=193528
+
 ### Heroku
 
-[Alessandro Tagliapietra](https://github.com/alex88) maintains an
+Set [NODE_MODULES_CACHE](https://devcenter.heroku.com/articles/nodejs-support#cache-behavior)
-[Heroku buildpack for libvips](https://github.com/alex88/heroku-buildpack-vips)
+to `false` when using the `yarn` package manager.
-and its dependencies.
 
 ### Docker
 
@@ -126,35 +140,145 @@ docker pull marcbachmann/libvips
 docker pull wjordan/libvips
 ```
 
+[Tailor Brands](https://github.com/TailorBrands) maintain
+[Debian-based Dockerfiles for libvips and nodejs](https://github.com/TailorBrands/docker-libvips).
+
+```sh
+docker pull tailor/docker-libvips
+```
+
 ### AWS Lambda
 
-In order to use sharp on AWS Lambda, you need to [create a deployment package](http://docs.aws.amazon.com/lambda/latest/dg/nodejs-create-deployment-pkg.html). Because sharp
+Set the Lambda runtime to Node.js 8.10.
-downloads and links libraries for the current platform during `npm install` you have to
-do this on a system similar to the [Lambda Execution Environment](http://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html). The easiest ways to do this, is to setup a
-small t2.micro instance using the AMI ID listed in the previous link, ssh into it as ec2-user
-and follow the instructions below.
 
-Install depencies:
+The binaries in the `node_modules` directory of the
+[deployment package](https://docs.aws.amazon.com/lambda/latest/dg/nodejs-create-deployment-pkg.html)
+must be for the Linux x64 platform/architecture.
+
+On non-Linux machines such as OS X and Windows run the following:
 
 ```sh
-sudo yum-config-manager --enable epel
+rm -rf node_modules/sharp
-sudo yum install -y nodejs gcc-c++
+npm install --arch=x64 --platform=linux --target=8.10.0 sharp
-curl -s https://www.npmjs.com/install.sh | sudo sh
 ```
 
-Copy your code and package.json to the instance using `scp` and create a deployment package:
+Alternatively a Docker container closely matching the Lambda runtime can be used:
 
 ```sh
-cd sharp-lambda-example
+rm -rf node_modules/sharp
-npm install
+docker run -v "$PWD":/var/task lambci/lambda:build-nodejs8.10 npm install sharp
-zip -ur9 ../sharp-lambda-example.zip index.js node_modules
 ```
 
-You can now download your deployment ZIP using `scp` and upload it to Lambda.
+To get the best performance select the largest memory available.
+A 1536 MB function provides ~12x more CPU time than a 128 MB function.
 
-**Performance Tip:** To get the best performance on Lambda choose the largest memory available because this also gives you the most cpu time (a 1536 MB function is 12x faster than a 128 MB function).
+### NW.js
+
+Run the `nw-gyp` tool after installation.
+
+```sh
+cd node-modules/sharp
+nw-gyp rebuild --arch=x64 --target=[your nw version]
+node node_modules/sharp/install/dll-copy
+```
+
+[http://docs.nwjs.io/en/latest/For%20Users/Advanced/Use%20Native%20Node%20Modules/](http://docs.nwjs.io/en/latest/For%20Users/Advanced/Use%20Native%20Node%20Modules/)
 
 ### Build tools
 
 * [gulp-responsive](https://www.npmjs.com/package/gulp-responsive)
 * [grunt-sharp](https://www.npmjs.com/package/grunt-sharp)
+
+### Coding tools
+
+* [Sharp TypeScript Types](https://www.npmjs.com/package/@types/sharp)
+
+### CLI tools
+
+* [sharp-cli](https://www.npmjs.com/package/sharp-cli)
+
+### Security
+
+Many users of this module process untrusted, user-supplied images,
+but there are aspects of security to consider when doing so.
+
+It is possible to compile libvips with support for various third-party image loaders.
+Each of these libraries has undergone differing levels of security testing.
+
+Whilst tools such as [American Fuzzy Lop](http://lcamtuf.coredump.cx/afl/)
+and [Valgrind](http://valgrind.org/) have been used to test
+the most popular web-based formats, as well as libvips itself,
+you are advised to perform your own testing and sandboxing.
+
+### Pre-compiled libvips binaries
+
+This module will attempt to download a pre-compiled bundle of libvips
+and its dependencies on Linux and Windows machines under either of these
+conditions:
+
+1. If a global installation of libvips that meets the
+minimum version requirement cannot be found;
+1. If `SHARP_IGNORE_GLOBAL_LIBVIPS` environment variable is set.
+
+```sh
+SHARP_IGNORE_GLOBAL_LIBVIPS=1 npm install sharp
+```
+
+Should you need to manually download and inspect these files,
+you can do so via
+[https://github.com/lovell/sharp-libvips/releases](https://github.com/lovell/sharp-libvips/releases)
+
+Should you wish to install these from your own location,
+set the `sharp_dist_base_url` npm config option, e.g.
+
+```sh
+npm config set sharp_dist_base_url "https://hostname/path/"
+npm install sharp
+```
+
+or set the `SHARP_DIST_BASE_URL` environment variable, e.g.
+
+```sh
+SHARP_DIST_BASE_URL="https://hostname/path/" npm install sharp
+```
+
+to use `https://hostname/path/libvips-x.y.z-platform.tar.gz`.
+
+### Licences
+
+This module is licensed under the terms of the
+[Apache 2.0 Licence](https://github.com/lovell/sharp/blob/master/LICENSE).
+
+The libraries downloaded and used by this module
+are done so under the terms of the following licences,
+all of which are compatible with the Apache 2.0 Licence.
+
+Use of libraries under the terms of the LGPLv3 is via the
+"any later version" clause of the LGPLv2 or LGPLv2.1.
+
+| Library       | Used under the terms of                                                                                  |
+|---------------|----------------------------------------------------------------------------------------------------------|
+| cairo         | Mozilla Public License 2.0                                                                               |
+| expat         | MIT Licence                                                                                              |
+| fontconfig    | [fontconfig Licence](https://cgit.freedesktop.org/fontconfig/tree/COPYING) (BSD-like)                    |
+| freetype      | [freetype Licence](http://git.savannah.gnu.org/cgit/freetype/freetype2.git/tree/docs/FTL.TXT) (BSD-like) |
+| fribidi       | LGPLv3                                                                                                   |
+| gettext       | LGPLv3                                                                                                   |
+| giflib        | MIT Licence                                                                                              |
+| glib          | LGPLv3                                                                                                   |
+| harfbuzz      | MIT Licence                                                                                              |
+| lcms          | MIT Licence                                                                                              |
+| libcroco      | LGPLv3                                                                                                   |
+| libexif       | LGPLv3                                                                                                   |
+| libffi        | MIT Licence                                                                                              |
+| libgsf        | LGPLv3                                                                                                   |
+| libjpeg-turbo | [zlib License, IJG License](https://github.com/libjpeg-turbo/libjpeg-turbo/blob/master/LICENSE.md)       |
+| libpng        | [libpng License](http://www.libpng.org/pub/png/src/libpng-LICENSE.txt)                                   |
+| librsvg       | LGPLv3                                                                                                   |
+| libtiff       | [libtiff License](http://www.libtiff.org/misc.html) (BSD-like)                                           |
+| libvips       | LGPLv3                                                                                                   |
+| libwebp       | New BSD License                                                                                          |
+| libxml2       | MIT Licence                                                                                              |
+| pango         | LGPLv3                                                                                                   |
+| pixman        | MIT Licence                                                                                              |
+| zlib          | [zlib Licence](https://github.com/madler/zlib/blob/master/zlib.h)                                        |

docs/performance.md

@@ -2,60 +2,59 @@
 
 ### Test environment
 
-* AWS EC2 [c4.xlarge](http://aws.amazon.com/ec2/instance-types/#c4) (4x E5-2666 v3 @2.90GHz)
+* AWS EC2 eu-west-1 [c5.large](https://aws.amazon.com/ec2/instance-types/c5/) (2x Xeon Platinum 8124M CPU @ 3.00GHz)
-* Amazon Linux 2015.09.1
+* Ubuntu 18.04 (hvm-ssd/ubuntu-bionic-18.04-amd64-server-20180912 ami-00035f41c82244dab)
-* Node.js v5.5.0
+* Node.js v10.11.0
 
 ### The contenders
 
-* [jimp](https://www.npmjs.com/package/jimp) v0.2.20 - Image processing in pure JavaScript. Bilinear interpolation only.
+* [jimp](https://www.npmjs.com/package/jimp) v0.5.3 - Image processing in pure JavaScript. Provides bicubic interpolation.
-* [lwip](https://www.npmjs.com/package/lwip) v0.0.8 - Wrapper around CImg, compiles dependencies from source.
+* [mapnik](https://www.npmjs.org/package/mapnik) v4.0.1 - Whilst primarily a map renderer, Mapnik contains bitmap image utilities.
-* [imagemagick-native](https://www.npmjs.com/package/imagemagick-native) @47c7329 - Wrapper around libmagick++, supports Buffers only.
+* [imagemagick-native](https://www.npmjs.com/package/imagemagick-native) v1.9.3 - Wrapper around libmagick++, supports Buffers only.
 * [imagemagick](https://www.npmjs.com/package/imagemagick) v0.1.3 - Supports filesystem only and "*has been unmaintained for a long time*".
-* [gm](https://www.npmjs.com/package/gm) v1.21.0 - Fully featured wrapper around GraphicsMagick's `gm` command line utility.
+* [gm](https://www.npmjs.com/package/gm) v1.23.1 - Fully featured wrapper around GraphicsMagick's `gm` command line utility.
-* sharp v0.13.0 / libvips v8.2.2 - Caching within libvips disabled to ensure a fair comparison.
+* sharp v0.21.0 / libvips v8.7.0 - Caching within libvips disabled to ensure a fair comparison.
 
 ### The task
 
-Decompress a 2725x2225 JPEG image, resize to 720x480 using bicubic interpolation (where available), then compress to JPEG.
+Decompress a 2725x2225 JPEG image,
+resize to 720x588 using Lanczos 3 resampling (where available),
+then compress to JPEG at a "quality" setting of 80.
 
 ### Results
 
 | Module             | Input  | Output | Ops/sec | Speed-up |
 | :----------------- | :----- | :----- | ------: | -------: |
-| jimp (bilinear)    | file   | file   |    1.04 |      1.0 |
+| jimp               | buffer | buffer |    0.71 |      1.0 |
-| jimp (bilinear)    | buffer | buffer |    1.07 |      1.0 |
+| mapnik             | buffer | buffer |    3.32 |      4.7 |
-| lwip               | file   | file   |    1.13 |      1.1 |
+| gm                 | buffer | buffer |    3.97 |      5.6 |
-| lwip               | buffer | buffer |    1.13 |      1.1 |
+| imagemagick-native | buffer | buffer |    4.06 |      5.7 |
-| imagemagick-native | buffer | buffer |    1.65 |      1.6 |
+| imagemagick        | file   | file   |    4.24 |      6.0 |
-| imagemagick        | file   | file   |    5.02 |      4.8 |
+| sharp              | stream | stream |   25.30 |     35.6 |
-| gm                 | buffer | buffer |    5.36 |      5.2 |
+| sharp              | file   | file   |   26.17 |     36.9 |
-| gm                 | file   | file   |    5.39 |      5.2 |
+| sharp              | buffer | buffer |   26.45 |     37.3 |
-| sharp              | stream | stream |   22.00 |     21.2 |
-| sharp              | file   | file   |   22.87 |     22.0 |
-| sharp              | file   | buffer |   23.03 |     22.1 |
-| sharp              | buffer | file   |   23.10 |     22.2 |
-| sharp              | buffer | buffer |   23.21 |     22.3 |
 
-Greater performance can be expected with caching enabled (default) and using 8+ core machines.
+Greater libvips performance can be expected with caching enabled (default)
+and using 8+ core machines, especially those with larger L1/L2 CPU caches.
 
 The I/O limits of the relevant (de)compression library will generally determine maximum throughput.
 
 ### Benchmark test prerequisites
 
-Requires both _ImageMagick_ and _GraphicsMagick_:
+Requires _ImageMagick_, _GraphicsMagick_ and _Mapnik_:
 
 ```sh
 brew install imagemagick
 brew install graphicsmagick
+brew install mapnik
 ```
 
 ```sh
-sudo apt-get install imagemagick libmagick++-dev graphicsmagick
+sudo apt-get install imagemagick libmagick++-dev graphicsmagick libmapnik-dev
 ```
 
 ```sh
-sudo yum install ImageMagick-devel ImageMagick-c++-devel GraphicsMagick
+sudo yum install ImageMagick-devel ImageMagick-c++-devel GraphicsMagick mapnik-devel
 ```
 
 ### Running the benchmark test

install/dll-copy.js

@@ -0,0 +1,35 @@
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+
+const copyFileSync = require('fs-copy-file-sync');
+const libvips = require('../lib/libvips');
+const npmLog = require('npmlog');
+
+if (process.platform === 'win32') {
+  const buildDir = path.join(__dirname, '..', 'build');
+  const buildReleaseDir = path.join(buildDir, 'Release');
+  npmLog.info('sharp', `Creating ${buildReleaseDir}`);
+  try {
+    libvips.mkdirSync(buildDir);
+    libvips.mkdirSync(buildReleaseDir);
+  } catch (err) {}
+  const vendorLibDir = path.join(__dirname, '..', 'vendor', 'lib');
+  npmLog.info('sharp', `Copying DLLs from ${vendorLibDir} to ${buildReleaseDir}`);
+  try {
+    fs
+      .readdirSync(vendorLibDir)
+      .filter(function (filename) {
+        return /\.dll$/.test(filename);
+      })
+      .forEach(function (filename) {
+        copyFileSync(
+          path.join(vendorLibDir, filename),
+          path.join(buildReleaseDir, filename)
+        );
+      });
+  } catch (err) {
+    npmLog.error('sharp', err.message);
+  }
+}

install/libvips.js

@@ -0,0 +1,103 @@
+'use strict';
+
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+
+const detectLibc = require('detect-libc');
+const npmLog = require('npmlog');
+const semver = require('semver');
+const simpleGet = require('simple-get');
+const tar = require('tar');
+const copyFileSync = require('fs-copy-file-sync');
+
+const agent = require('../lib/agent');
+const libvips = require('../lib/libvips');
+const platform = require('../lib/platform');
+
+const minimumLibvipsVersion = libvips.minimumLibvipsVersion;
+const distBaseUrl = process.env.npm_config_sharp_dist_base_url || process.env.SHARP_DIST_BASE_URL || `https://github.com/lovell/sharp-libvips/releases/download/v${minimumLibvipsVersion}/`;
+
+const fail = function (err) {
+  npmLog.error('sharp', err.message);
+  npmLog.error('sharp', 'Please see http://sharp.pixelplumbing.com/page/install');
+  process.exit(1);
+};
+
+const extractTarball = function (tarPath) {
+  const vendorPath = path.join(__dirname, '..', 'vendor');
+  libvips.mkdirSync(vendorPath);
+  tar
+    .extract({
+      file: tarPath,
+      cwd: vendorPath,
+      strict: true
+    })
+    .catch(fail);
+};
+
+try {
+  const useGlobalLibvips = libvips.useGlobalLibvips();
+  if (useGlobalLibvips) {
+    const globalLibvipsVersion = libvips.globalLibvipsVersion();
+    npmLog.info('sharp', `Detected globally-installed libvips v${globalLibvipsVersion}`);
+    npmLog.info('sharp', 'Building from source via node-gyp');
+    process.exit(1);
+  } else if (libvips.hasVendoredLibvips()) {
+    npmLog.info('sharp', `Using existing vendored libvips v${minimumLibvipsVersion}`);
+  } else {
+    // Is this arch/platform supported?
+    const arch = process.env.npm_config_arch || process.arch;
+    const platformAndArch = platform();
+    if (platformAndArch === 'win32-ia32') {
+      throw new Error('Windows x86 (32-bit) node.exe is not supported');
+    }
+    if (arch === 'ia32') {
+      throw new Error(`Intel Architecture 32-bit systems require manual installation of libvips >= ${minimumLibvipsVersion}`);
+    }
+    if (platformAndArch === 'freebsd-x64' || platformAndArch === 'openbsd-x64' || platformAndArch === 'sunos-x64') {
+      throw new Error(`BSD/SunOS systems require manual installation of libvips >= ${minimumLibvipsVersion}`);
+    }
+    if (detectLibc.family === detectLibc.GLIBC && detectLibc.version && semver.lt(`${detectLibc.version}.0`, '2.13.0')) {
+      throw new Error(`Use with glibc version ${detectLibc.version} requires manual installation of libvips >= ${minimumLibvipsVersion}`);
+    }
+    // Download to per-process temporary file
+    const tarFilename = ['libvips', minimumLibvipsVersion, platformAndArch].join('-') + '.tar.gz';
+    const tarPathCache = path.join(libvips.cachePath(), tarFilename);
+    if (fs.existsSync(tarPathCache)) {
+      npmLog.info('sharp', `Using cached ${tarPathCache}`);
+      extractTarball(tarPathCache);
+    } else {
+      const tarPathTemp = path.join(os.tmpdir(), `${process.pid}-${tarFilename}`);
+      const tmpFile = fs.createWriteStream(tarPathTemp);
+      const url = distBaseUrl + tarFilename;
+      npmLog.info('sharp', `Downloading ${url}`);
+      simpleGet({ url: url, agent: agent() }, function (err, response) {
+        if (err) {
+          throw err;
+        }
+        if (response.statusCode !== 200) {
+          throw new Error(`Status ${response.statusCode}`);
+        }
+        response
+          .on('error', fail)
+          .pipe(tmpFile);
+      });
+      tmpFile
+        .on('error', fail)
+        .on('close', function () {
+          try {
+            // Attempt to rename
+            fs.renameSync(tarPathTemp, tarPathCache);
+          } catch (err) {
+            // Fall back to copy and unlink
+            copyFileSync(tarPathTemp, tarPathCache);
+            fs.unlinkSync(tarPathTemp);
+          }
+          extractTarball(tarPathCache);
+        });
+    }
+  }
+} catch (err) {
+  fail(err);
+}

lib/agent.js

@@ -0,0 +1,37 @@
+'use strict';
+
+const url = require('url');
+const tunnelAgent = require('tunnel-agent');
+
+const is = require('./is');
+
+const proxies = [
+  'HTTPS_PROXY',
+  'https_proxy',
+  'HTTP_PROXY',
+  'http_proxy',
+  'npm_config_https_proxy',
+  'npm_config_proxy'
+];
+
+function env (key) {
+  return process.env[key];
+}
+
+module.exports = function () {
+  try {
+    const proxy = url.parse(proxies.map(env).find(is.string));
+    const tunnel = proxy.protocol === 'https:'
+      ? tunnelAgent.httpsOverHttps
+      : tunnelAgent.httpsOverHttp;
+    return tunnel({
+      proxy: {
+        port: Number(proxy.port),
+        host: proxy.hostname,
+        proxyAuth: proxy.auth
+      }
+    });
+  } catch (err) {
+    return null;
+  }
+};

lib/channel.js

@@ -0,0 +1,147 @@
+'use strict';
+
+const is = require('./is');
+
+/**
+ * Boolean operations for bandbool.
+ * @private
+ */
+const bool = {
+  and: 'and',
+  or: 'or',
+  eor: 'eor'
+};
+
+/**
+ * Remove alpha channel, if any. This is a no-op if the image does not have an alpha channel.
+ *
+ * @example
+ * sharp('rgba.png')
+ *   .removeAlpha()
+ *   .toFile('rgb.png', function(err, info) {
+ *     // rgb.png is a 3 channel image without an alpha channel
+ *   });
+ *
+ * @returns {Sharp}
+ */
+function removeAlpha () {
+  this.options.removeAlpha = true;
+  return this;
+}
+
+/**
+ * Ensure alpha channel, if missing. The added alpha channel will be fully opaque. This is a no-op if the image already has an alpha channel.
+ *
+ * @example
+ * sharp('rgb.jpg')
+ *   .ensureAlpha()
+ *   .toFile('rgba.png', function(err, info) {
+ *     // rgba.png is a 4 channel image with a fully opaque alpha channel
+ *   });
+ *
+ * @returns {Sharp}
+ */
+function ensureAlpha () {
+  this.options.ensureAlpha = true;
+  return this;
+}
+
+/**
+ * Extract a single channel from a multi-channel image.
+ *
+ * @example
+ * sharp(input)
+ *   .extractChannel('green')
+ *   .toFile('input_green.jpg', function(err, info) {
+ *     // info.channels === 1
+ *     // input_green.jpg contains the green channel of the input image
+ *    });
+ *
+ * @param {Number|String} channel - zero-indexed band number to extract, or `red`, `green` or `blue` as alternative to `0`, `1` or `2` respectively.
+ * @returns {Sharp}
+ * @throws {Error} Invalid channel
+ */
+function extractChannel (channel) {
+  if (channel === 'red') {
+    channel = 0;
+  } else if (channel === 'green') {
+    channel = 1;
+  } else if (channel === 'blue') {
+    channel = 2;
+  }
+  if (is.integer(channel) && is.inRange(channel, 0, 4)) {
+    this.options.extractChannel = channel;
+  } else {
+    throw new Error('Cannot extract invalid channel ' + channel);
+  }
+  return this;
+}
+
+/**
+ * Join one or more channels to the image.
+ * The meaning of the added channels depends on the output colourspace, set with `toColourspace()`.
+ * By default the output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+ * Channel ordering follows vips convention:
+ * - sRGB: 0: Red, 1: Green, 2: Blue, 3: Alpha.
+ * - CMYK: 0: Magenta, 1: Cyan, 2: Yellow, 3: Black, 4: Alpha.
+ *
+ * Buffers may be any of the image formats supported by sharp: JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data.
+ * For raw pixel input, the `options` object should contain a `raw` attribute, which follows the format of the attribute of the same name in the `sharp()` constructor.
+ *
+ * @param {Array<String|Buffer>|String|Buffer} images - one or more images (file paths, Buffers).
+ * @param {Object} options - image options, see `sharp()` constructor.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function joinChannel (images, options) {
+  if (Array.isArray(images)) {
+    images.forEach(function (image) {
+      this.options.joinChannelIn.push(this._createInputDescriptor(image, options));
+    }, this);
+  } else {
+    this.options.joinChannelIn.push(this._createInputDescriptor(images, options));
+  }
+  return this;
+}
+
+/**
+ * Perform a bitwise boolean operation on all input image channels (bands) to produce a single channel output image.
+ *
+ * @example
+ * sharp('3-channel-rgb-input.png')
+ *   .bandbool(sharp.bool.and)
+ *   .toFile('1-channel-output.png', function (err, info) {
+ *     // The output will be a single channel image where each pixel `P = R & G & B`.
+ *     // If `I(1,1) = [247, 170, 14] = [0b11110111, 0b10101010, 0b00001111]`
+ *     // then `O(1,1) = 0b11110111 & 0b10101010 & 0b00001111 = 0b00000010 = 2`.
+ *   });
+ *
+ * @param {String} boolOp - one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function bandbool (boolOp) {
+  if (is.string(boolOp) && is.inArray(boolOp, ['and', 'or', 'eor'])) {
+    this.options.bandBoolOp = boolOp;
+  } else {
+    throw new Error('Invalid bandbool operation ' + boolOp);
+  }
+  return this;
+}
+
+/**
+ * Decorate the Sharp prototype with channel-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  Object.assign(Sharp.prototype, {
+    // Public instance functions
+    removeAlpha,
+    ensureAlpha,
+    extractChannel,
+    joinChannel,
+    bandbool
+  });
+  // Class attributes
+  Sharp.bool = bool;
+};

lib/colour.js

@@ -0,0 +1,141 @@
+'use strict';
+
+const deprecate = require('util').deprecate;
+
+const color = require('color');
+const is = require('./is');
+
+/**
+ * Colourspaces.
+ * @private
+ */
+const colourspace = {
+  multiband: 'multiband',
+  'b-w': 'b-w',
+  bw: 'b-w',
+  cmyk: 'cmyk',
+  srgb: 'srgb'
+};
+
+/**
+ * @deprecated
+ * @private
+ */
+function background (rgba) {
+  const colour = color(rgba);
+  const background = [
+    colour.red(),
+    colour.green(),
+    colour.blue(),
+    Math.round(colour.alpha() * 255)
+  ];
+  this.options.resizeBackground = background;
+  this.options.extendBackground = background;
+  this.options.flattenBackground = background.slice(0, 3);
+  return this;
+}
+
+/**
+ * Tint the image using the provided chroma while preserving the image luminance.
+ * An alpha channel may be present and will be unchanged by the operation.
+ *
+ * @param {String|Object} rgb - parsed by the [color](https://www.npmjs.org/package/color) module to extract chroma values.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameter
+ */
+function tint (rgb) {
+  const colour = color(rgb);
+  this.options.tintA = colour.a();
+  this.options.tintB = colour.b();
+  return this;
+}
+
+/**
+ * Convert to 8-bit greyscale; 256 shades of grey.
+ * This is a linear operation. If the input image is in a non-linear colour space such as sRGB, use `gamma()` with `greyscale()` for the best results.
+ * By default the output image will be web-friendly sRGB and contain three (identical) color channels.
+ * This may be overridden by other sharp operations such as `toColourspace('b-w')`,
+ * which will produce an output image containing one color channel.
+ * An alpha channel may be present, and will be unchanged by the operation.
+ * @param {Boolean} [greyscale=true]
+ * @returns {Sharp}
+ */
+function greyscale (greyscale) {
+  this.options.greyscale = is.bool(greyscale) ? greyscale : true;
+  return this;
+}
+
+/**
+ * Alternative spelling of `greyscale`.
+ * @param {Boolean} [grayscale=true]
+ * @returns {Sharp}
+ */
+function grayscale (grayscale) {
+  return this.greyscale(grayscale);
+}
+
+/**
+ * Set the output colourspace.
+ * By default output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+ * @param {String} [colourspace] - output colourspace e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...](https://github.com/libvips/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568)
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function toColourspace (colourspace) {
+  if (!is.string(colourspace)) {
+    throw new Error('Invalid output colourspace ' + colourspace);
+  }
+  this.options.colourspace = colourspace;
+  return this;
+}
+
+/**
+ * Alternative spelling of `toColourspace`.
+ * @param {String} [colorspace] - output colorspace.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function toColorspace (colorspace) {
+  return this.toColourspace(colorspace);
+}
+
+/**
+ * Update a colour attribute of the this.options Object.
+ * @private
+ * @param {String} key
+ * @param {String|Object} val
+ * @throws {Error} Invalid key
+ */
+function _setColourOption (key, val) {
+  if (is.object(val) || is.string(val)) {
+    const colour = color(val);
+    this.options[key] = [
+      colour.red(),
+      colour.green(),
+      colour.blue(),
+      Math.round(colour.alpha() * 255)
+    ];
+  }
+}
+
+/**
+ * Decorate the Sharp prototype with colour-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  Object.assign(Sharp.prototype, {
+    // Public
+    tint,
+    greyscale,
+    grayscale,
+    toColourspace,
+    toColorspace,
+    // Private
+    _setColourOption
+  });
+  // Class attributes
+  Sharp.colourspace = colourspace;
+  Sharp.colorspace = colourspace;
+  // Deprecated
+  Sharp.prototype.background = deprecate(background, 'background(background) is deprecated, use resize({ background }), extend({ background }) or flatten({ background }) instead');
+};

lib/composite.js

@@ -0,0 +1,95 @@
+'use strict';
+
+const is = require('./is');
+
+/**
+ * Overlay (composite) an image over the processed (resized, extracted etc.) image.
+ *
+ * The overlay image must be the same size or smaller than the processed image.
+ * If both `top` and `left` options are provided, they take precedence over `gravity`.
+ *
+ * If the overlay image contains an alpha channel then composition with premultiplication will occur.
+ *
+ * @example
+ * sharp('input.png')
+ *   .rotate(180)
+ *   .resize(300)
+ *   .flatten( { background: '#ff6600' } )
+ *   .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
+ *   .sharpen()
+ *   .withMetadata()
+ *   .webp( { quality: 90 } )
+ *   .toBuffer()
+ *   .then(function(outputBuffer) {
+ *     // outputBuffer contains upside down, 300px wide, alpha channel flattened
+ *     // onto orange background, composited with overlay.png with SE gravity,
+ *     // sharpened, with metadata, 90% quality WebP image data. Phew!
+ *   });
+ *
+ * @param {(Buffer|String)} overlay - Buffer containing image data or String containing the path to an image file.
+ * @param {Object} [options]
+ * @param {String} [options.gravity='centre'] - gravity at which to place the overlay.
+ * @param {Number} [options.top] - the pixel offset from the top edge.
+ * @param {Number} [options.left] - the pixel offset from the left edge.
+ * @param {Boolean} [options.tile=false] - set to true to repeat the overlay image across the entire image with the given `gravity`.
+ * @param {Boolean} [options.cutout=false] - set to true to apply only the alpha channel of the overlay image to the input image, giving the appearance of one image being cut out of another.
+ * @param {Number} [options.density=72] - number representing the DPI for vector overlay image.
+ * @param {Object} [options.raw] - describes overlay when using raw pixel data.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels]
+ * @param {Object} [options.create] - describes a blank overlay to be created.
+ * @param {Number} [options.create.width]
+ * @param {Number} [options.create.height]
+ * @param {Number} [options.create.channels] - 3-4
+ * @param {String|Object} [options.create.background] - parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function overlayWith (overlay, options) {
+  this.options.overlay = this._createInputDescriptor(overlay, options, {
+    allowStream: false
+  });
+  if (is.object(options)) {
+    if (is.defined(options.tile)) {
+      if (is.bool(options.tile)) {
+        this.options.overlayTile = options.tile;
+      } else {
+        throw new Error('Invalid overlay tile ' + options.tile);
+      }
+    }
+    if (is.defined(options.cutout)) {
+      if (is.bool(options.cutout)) {
+        this.options.overlayCutout = options.cutout;
+      } else {
+        throw new Error('Invalid overlay cutout ' + options.cutout);
+      }
+    }
+    if (is.defined(options.left) || is.defined(options.top)) {
+      if (is.integer(options.left) && options.left >= 0 && is.integer(options.top) && options.top >= 0) {
+        this.options.overlayXOffset = options.left;
+        this.options.overlayYOffset = options.top;
+      } else {
+        throw new Error('Invalid overlay left ' + options.left + ' and/or top ' + options.top);
+      }
+    }
+    if (is.defined(options.gravity)) {
+      if (is.integer(options.gravity) && is.inRange(options.gravity, 0, 8)) {
+        this.options.overlayGravity = options.gravity;
+      } else if (is.string(options.gravity) && is.integer(this.constructor.gravity[options.gravity])) {
+        this.options.overlayGravity = this.constructor.gravity[options.gravity];
+      } else {
+        throw new Error('Unsupported overlay gravity ' + options.gravity);
+      }
+    }
+  }
+  return this;
+}
+
+/**
+ * Decorate the Sharp prototype with composite-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  Sharp.prototype.overlayWith = overlayWith;
+};

lib/constructor.js

@@ -0,0 +1,246 @@
+'use strict';
+
+const path = require('path');
+const util = require('util');
+const stream = require('stream');
+const events = require('events');
+const is = require('./is');
+
+require('./libvips').hasVendoredLibvips();
+const sharp = require('bindings')('sharp.node');
+
+// Use NODE_DEBUG=sharp to enable libvips warnings
+const debuglog = util.debuglog('sharp');
+
+/**
+ * @class Sharp
+ *
+ * Constructor factory to create an instance of `sharp`, to which further methods are chained.
+ *
+ * JPEG, PNG, WebP or TIFF format image data can be streamed out from this object.
+ * When using Stream based output, derived attributes are available from the `info` event.
+ *
+ * Implements the [stream.Duplex](http://nodejs.org/api/stream.html#stream_class_stream_duplex) class.
+ *
+ * @example
+ * sharp('input.jpg')
+ *   .resize(300, 200)
+ *   .toFile('output.jpg', function(err) {
+ *     // output.jpg is a 300 pixels wide and 200 pixels high image
+ *     // containing a scaled and cropped version of input.jpg
+ *   });
+ *
+ * @example
+ * // Read image data from readableStream,
+ * // resize to 300 pixels wide,
+ * // emit an 'info' event with calculated dimensions
+ * // and finally write image data to writableStream
+ * var transformer = sharp()
+ *   .resize(300)
+ *   .on('info', function(info) {
+ *     console.log('Image height is ' + info.height);
+ *   });
+ * readableStream.pipe(transformer).pipe(writableStream);
+ *
+ * @example
+ * // Create a blank 300x200 PNG image of semi-transluent red pixels
+ * sharp({
+ *   create: {
+ *     width: 300,
+ *     height: 200,
+ *     channels: 4,
+ *     background: { r: 255, g: 0, b: 0, alpha: 0.5 }
+ *   }
+ * })
+ * .png()
+ * .toBuffer()
+ * .then( ... );
+ *
+ * @param {(Buffer|String)} [input] - if present, can be
+ *  a Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
+ *  a String containing the path to an JPEG, PNG, WebP, GIF, SVG or TIFF image file.
+ *  JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data can be streamed into the object when not present.
+ * @param {Object} [options] - if present, is an Object with optional attributes.
+ * @param {Boolean} [options.failOnError=false] - by default apply a "best effort"
+ *  to decode images, even if the data is corrupt or invalid. Set this flag to true
+ *  if you'd rather halt processing and raise an error when loading invalid images.
+ * @param {Number} [options.density=72] - number representing the DPI for vector images.
+ * @param {Number} [options.page=0] - page number to extract for multi-page input (GIF, TIFF)
+ * @param {Object} [options.raw] - describes raw pixel input image data. See `raw()` for pixel ordering.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels] - 1-4
+ * @param {Object} [options.create] - describes a new image to be created.
+ * @param {Number} [options.create.width]
+ * @param {Number} [options.create.height]
+ * @param {Number} [options.create.channels] - 3-4
+ * @param {String|Object} [options.create.background] - parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const Sharp = function (input, options) {
+  if (arguments.length === 1 && !is.defined(input)) {
+    throw new Error('Invalid input');
+  }
+  if (!(this instanceof Sharp)) {
+    return new Sharp(input, options);
+  }
+  stream.Duplex.call(this);
+  this.options = {
+    // input options
+    sequentialRead: false,
+    limitInputPixels: Math.pow(0x3FFF, 2),
+    // ICC profiles
+    iccProfilePath: path.join(__dirname, 'icc') + path.sep,
+    // resize options
+    topOffsetPre: -1,
+    leftOffsetPre: -1,
+    widthPre: -1,
+    heightPre: -1,
+    topOffsetPost: -1,
+    leftOffsetPost: -1,
+    widthPost: -1,
+    heightPost: -1,
+    width: -1,
+    height: -1,
+    canvas: 'crop',
+    position: 0,
+    resizeBackground: [0, 0, 0, 255],
+    useExifOrientation: false,
+    angle: 0,
+    rotationAngle: 0,
+    rotationBackground: [0, 0, 0, 255],
+    rotateBeforePreExtract: false,
+    flip: false,
+    flop: false,
+    extendTop: 0,
+    extendBottom: 0,
+    extendLeft: 0,
+    extendRight: 0,
+    extendBackground: [0, 0, 0, 255],
+    withoutEnlargement: false,
+    kernel: 'lanczos3',
+    fastShrinkOnLoad: true,
+    // operations
+    tintA: 128,
+    tintB: 128,
+    flatten: false,
+    flattenBackground: [0, 0, 0],
+    negate: false,
+    medianSize: 0,
+    blurSigma: 0,
+    sharpenSigma: 0,
+    sharpenFlat: 1,
+    sharpenJagged: 2,
+    threshold: 0,
+    thresholdGrayscale: true,
+    trimThreshold: 0,
+    gamma: 0,
+    gammaOut: 0,
+    greyscale: false,
+    normalise: 0,
+    booleanBufferIn: null,
+    booleanFileIn: '',
+    joinChannelIn: [],
+    extractChannel: -1,
+    removeAlpha: false,
+    ensureAlpha: false,
+    colourspace: 'srgb',
+    // overlay
+    overlayGravity: 0,
+    overlayXOffset: -1,
+    overlayYOffset: -1,
+    overlayTile: false,
+    overlayCutout: false,
+    // output
+    fileOut: '',
+    formatOut: 'input',
+    streamOut: false,
+    withMetadata: false,
+    withMetadataOrientation: -1,
+    resolveWithObject: false,
+    // output format
+    jpegQuality: 80,
+    jpegProgressive: false,
+    jpegChromaSubsampling: '4:2:0',
+    jpegTrellisQuantisation: false,
+    jpegOvershootDeringing: false,
+    jpegOptimiseScans: false,
+    jpegOptimiseCoding: true,
+    jpegQuantisationTable: 0,
+    pngProgressive: false,
+    pngCompressionLevel: 9,
+    pngAdaptiveFiltering: false,
+    pngPalette: false,
+    pngQuality: 100,
+    pngColours: 256,
+    pngDither: 1,
+    webpQuality: 80,
+    webpAlphaQuality: 100,
+    webpLossless: false,
+    webpNearLossless: false,
+    tiffQuality: 80,
+    tiffCompression: 'jpeg',
+    tiffPredictor: 'horizontal',
+    tiffPyramid: false,
+    tiffSquash: false,
+    tiffTile: false,
+    tiffTileHeight: 256,
+    tiffTileWidth: 256,
+    tiffXres: 1.0,
+    tiffYres: 1.0,
+    tileSize: 256,
+    tileOverlap: 0,
+    linearA: 1,
+    linearB: 0,
+    // Function to notify of libvips warnings
+    debuglog: debuglog,
+    // Function to notify of queue length changes
+    queueListener: function (queueLength) {
+      queue.emit('change', queueLength);
+    }
+  };
+  this.options.input = this._createInputDescriptor(input, options, { allowStream: true });
+  return this;
+};
+util.inherits(Sharp, stream.Duplex);
+
+/**
+ * An EventEmitter that emits a `change` event when a task is either:
+ * - queued, waiting for _libuv_ to provide a worker thread
+ * - complete
+ * @member
+ * @example
+ * sharp.queue.on('change', function(queueLength) {
+ *   console.log('Queue contains ' + queueLength + ' task(s)');
+ * });
+ */
+const queue = new events.EventEmitter();
+Sharp.queue = queue;
+
+/**
+ * An Object containing nested boolean values representing the available input and output formats/methods.
+ * @example
+ * console.log(sharp.format);
+ * @returns {Object}
+ */
+Sharp.format = sharp.format();
+
+/**
+ * An Object containing the version numbers of libvips and its dependencies.
+ * @member
+ * @example
+ * console.log(sharp.versions);
+ */
+Sharp.versions = {
+  vips: sharp.libvipsVersion()
+};
+try {
+  Sharp.versions = require('../vendor/versions.json');
+} catch (err) {}
+
+/**
+ * Export constructor.
+ * @private
+ */
+module.exports = Sharp;

lib/index.js

@@ -0,0 +1,13 @@
+'use strict';
+
+const Sharp = require('./constructor');
+require('./input')(Sharp);
+require('./resize')(Sharp);
+require('./composite')(Sharp);
+require('./operation')(Sharp);
+require('./colour')(Sharp);
+require('./channel')(Sharp);
+require('./output')(Sharp);
+require('./utility')(Sharp);
+
+module.exports = Sharp;

lib/input.js

@@ -0,0 +1,380 @@
+'use strict';
+
+const color = require('color');
+const is = require('./is');
+const sharp = require('../build/Release/sharp.node');
+
+/**
+ * Create Object containing input and input-related options.
+ * @private
+ */
+function _createInputDescriptor (input, inputOptions, containerOptions) {
+  const inputDescriptor = { failOnError: false };
+  if (is.string(input)) {
+    // filesystem
+    inputDescriptor.file = input;
+  } else if (is.buffer(input)) {
+    // Buffer
+    inputDescriptor.buffer = input;
+  } else if (is.plainObject(input) && !is.defined(inputOptions)) {
+    // Plain Object descriptor, e.g. create
+    inputOptions = input;
+  } else if (!is.defined(input) && is.object(containerOptions) && containerOptions.allowStream) {
+    // Stream
+    inputDescriptor.buffer = [];
+  } else {
+    throw new Error('Unsupported input ' + typeof input);
+  }
+  if (is.object(inputOptions)) {
+    // Fail on error
+    if (is.defined(inputOptions.failOnError)) {
+      if (is.bool(inputOptions.failOnError)) {
+        inputDescriptor.failOnError = inputOptions.failOnError;
+      } else {
+        throw new Error('Invalid failOnError (boolean) ' + inputOptions.failOnError);
+      }
+    }
+    // Density
+    if (is.defined(inputOptions.density)) {
+      if (is.inRange(inputOptions.density, 1, 2400)) {
+        inputDescriptor.density = inputOptions.density;
+      } else {
+        throw new Error('Invalid density (1 to 2400) ' + inputOptions.density);
+      }
+    }
+    // Raw pixel input
+    if (is.defined(inputOptions.raw)) {
+      if (
+        is.object(inputOptions.raw) &&
+        is.integer(inputOptions.raw.width) && inputOptions.raw.width > 0 &&
+        is.integer(inputOptions.raw.height) && inputOptions.raw.height > 0 &&
+        is.integer(inputOptions.raw.channels) && is.inRange(inputOptions.raw.channels, 1, 4)
+      ) {
+        inputDescriptor.rawWidth = inputOptions.raw.width;
+        inputDescriptor.rawHeight = inputOptions.raw.height;
+        inputDescriptor.rawChannels = inputOptions.raw.channels;
+      } else {
+        throw new Error('Expected width, height and channels for raw pixel input');
+      }
+    }
+    // Page input for multi-page TIFF
+    if (is.defined(inputOptions.page)) {
+      if (is.integer(inputOptions.page) && is.inRange(inputOptions.page, 0, 100000)) {
+        inputDescriptor.page = inputOptions.page;
+      }
+    }
+    // Create new image
+    if (is.defined(inputOptions.create)) {
+      if (
+        is.object(inputOptions.create) &&
+        is.integer(inputOptions.create.width) && inputOptions.create.width > 0 &&
+        is.integer(inputOptions.create.height) && inputOptions.create.height > 0 &&
+        is.integer(inputOptions.create.channels) && is.inRange(inputOptions.create.channels, 3, 4) &&
+        is.defined(inputOptions.create.background)
+      ) {
+        inputDescriptor.createWidth = inputOptions.create.width;
+        inputDescriptor.createHeight = inputOptions.create.height;
+        inputDescriptor.createChannels = inputOptions.create.channels;
+        const background = color(inputOptions.create.background);
+        inputDescriptor.createBackground = [
+          background.red(),
+          background.green(),
+          background.blue(),
+          Math.round(background.alpha() * 255)
+        ];
+        delete inputDescriptor.buffer;
+      } else {
+        throw new Error('Expected width, height, channels and background to create a new input image');
+      }
+    }
+  } else if (is.defined(inputOptions)) {
+    throw new Error('Invalid input options ' + inputOptions);
+  }
+  return inputDescriptor;
+}
+
+/**
+ * Handle incoming Buffer chunk on Writable Stream.
+ * @private
+ * @param {Buffer} chunk
+ * @param {String} encoding - unused
+ * @param {Function} callback
+ */
+function _write (chunk, encoding, callback) {
+  /* istanbul ignore else */
+  if (Array.isArray(this.options.input.buffer)) {
+    /* istanbul ignore else */
+    if (is.buffer(chunk)) {
+      if (this.options.input.buffer.length === 0) {
+        const that = this;
+        this.on('finish', function () {
+          that.streamInFinished = true;
+        });
+      }
+      this.options.input.buffer.push(chunk);
+      callback();
+    } else {
+      callback(new Error('Non-Buffer data on Writable Stream'));
+    }
+  } else {
+    callback(new Error('Unexpected data on Writable Stream'));
+  }
+}
+
+/**
+ * Flattens the array of chunks accumulated in input.buffer.
+ * @private
+ */
+function _flattenBufferIn () {
+  if (this._isStreamInput()) {
+    this.options.input.buffer = Buffer.concat(this.options.input.buffer);
+  }
+}
+
+/**
+ * Are we expecting Stream-based input?
+ * @private
+ * @returns {Boolean}
+ */
+function _isStreamInput () {
+  return Array.isArray(this.options.input.buffer);
+}
+
+/**
+ * Take a "snapshot" of the Sharp instance, returning a new instance.
+ * Cloned instances inherit the input of their parent instance.
+ * This allows multiple output Streams and therefore multiple processing pipelines to share a single input Stream.
+ *
+ * @example
+ * const pipeline = sharp().rotate();
+ * pipeline.clone().resize(800, 600).pipe(firstWritableStream);
+ * pipeline.clone().extract({ left: 20, top: 20, width: 100, height: 100 }).pipe(secondWritableStream);
+ * readableStream.pipe(pipeline);
+ * // firstWritableStream receives auto-rotated, resized readableStream
+ * // secondWritableStream receives auto-rotated, extracted region of readableStream
+ *
+ * @returns {Sharp}
+ */
+function clone () {
+  const that = this;
+  // Clone existing options
+  const clone = this.constructor.call();
+  clone.options = Object.assign({}, this.options);
+  // Pass 'finish' event to clone for Stream-based input
+  if (this._isStreamInput()) {
+    this.on('finish', function () {
+      // Clone inherits input data
+      that._flattenBufferIn();
+      clone.options.bufferIn = that.options.bufferIn;
+      clone.emit('finish');
+    });
+  }
+  return clone;
+}
+
+/**
+ * Fast access to (uncached) image metadata without decoding any compressed image data.
+ * A Promises/A+ promise is returned when `callback` is not provided.
+ *
+ * - `format`: Name of decoder used to decompress image data e.g. `jpeg`, `png`, `webp`, `gif`, `svg`
+ * - `size`: Total size of image in bytes, for Stream and Buffer input only
+ * - `width`: Number of pixels wide (EXIF orientation is not taken into consideration)
+ * - `height`: Number of pixels high (EXIF orientation is not taken into consideration)
+ * - `space`: Name of colour space interpretation e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...](https://github.com/libvips/libvips/blob/master/libvips/iofuncs/enumtypes.c#L636)
+ * - `channels`: Number of bands e.g. `3` for sRGB, `4` for CMYK
+ * - `depth`: Name of pixel depth format e.g. `uchar`, `char`, `ushort`, `float` [...](https://github.com/libvips/libvips/blob/master/libvips/iofuncs/enumtypes.c#L672)
+ * - `density`: Number of pixels per inch (DPI), if present
+ * - `chromaSubsampling`: String containing JPEG chroma subsampling, `4:2:0` or `4:4:4` for RGB, `4:2:0:4` or `4:4:4:4` for CMYK
+ * - `isProgressive`: Boolean indicating whether the image is interlaced using a progressive scan
+ * - `pages`: Number of pages this TIFF, GIF or PDF image contains.
+ * - `pageHeight`: Number of pixels high each page in this PDF image will be.
+ * - `hasProfile`: Boolean indicating the presence of an embedded ICC profile
+ * - `hasAlpha`: Boolean indicating the presence of an alpha transparency channel
+ * - `orientation`: Number value of the EXIF Orientation header, if present
+ * - `exif`: Buffer containing raw EXIF data, if present
+ * - `icc`: Buffer containing raw [ICC](https://www.npmjs.com/package/icc) profile data, if present
+ * - `iptc`: Buffer containing raw IPTC data, if present
+ * - `xmp`: Buffer containing raw XMP data, if present
+ *
+ * @example
+ * const image = sharp(inputJpg);
+ * image
+ *   .metadata()
+ *   .then(function(metadata) {
+ *     return image
+ *       .resize(Math.round(metadata.width / 2))
+ *       .webp()
+ *       .toBuffer();
+ *   })
+ *   .then(function(data) {
+ *     // data contains a WebP image half the width and height of the original JPEG
+ *   });
+ *
+ * @param {Function} [callback] - called with the arguments `(err, metadata)`
+ * @returns {Promise<Object>|Sharp}
+ */
+function metadata (callback) {
+  const that = this;
+  if (is.fn(callback)) {
+    if (this._isStreamInput()) {
+      this.on('finish', function () {
+        that._flattenBufferIn();
+        sharp.metadata(that.options, callback);
+      });
+    } else {
+      sharp.metadata(this.options, callback);
+    }
+    return this;
+  } else {
+    if (this._isStreamInput()) {
+      return new Promise(function (resolve, reject) {
+        that.on('finish', function () {
+          that._flattenBufferIn();
+          sharp.metadata(that.options, function (err, metadata) {
+            if (err) {
+              reject(err);
+            } else {
+              resolve(metadata);
+            }
+          });
+        });
+      });
+    } else {
+      return new Promise(function (resolve, reject) {
+        sharp.metadata(that.options, function (err, metadata) {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(metadata);
+          }
+        });
+      });
+    }
+  }
+}
+
+/**
+ * Access to pixel-derived image statistics for every channel in the image.
+ * A Promise is returned when `callback` is not provided.
+ *
+ * - `channels`: Array of channel statistics for each channel in the image. Each channel statistic contains
+ *     - `min` (minimum value in the channel)
+ *     - `max` (maximum value in the channel)
+ *     - `sum` (sum of all values in a channel)
+ *     - `squaresSum` (sum of squared values in a channel)
+ *     - `mean` (mean of the values in a channel)
+ *     - `stdev` (standard deviation for the values in a channel)
+ *     - `minX` (x-coordinate of one of the pixel where the minimum lies)
+ *     - `minY` (y-coordinate of one of the pixel where the minimum lies)
+ *     - `maxX` (x-coordinate of one of the pixel where the maximum lies)
+ *     - `maxY` (y-coordinate of one of the pixel where the maximum lies)
+ * - `isOpaque`: Value to identify if the image is opaque or transparent, based on the presence and use of alpha channel
+ * - `entropy`: Histogram-based estimation of greyscale entropy, discarding alpha channel if any (experimental)
+ *
+ * @example
+ * const image = sharp(inputJpg);
+ * image
+ *   .stats()
+ *   .then(function(stats) {
+ *      // stats contains the channel-wise statistics array and the isOpaque value
+ *   });
+ *
+ * @param {Function} [callback] - called with the arguments `(err, stats)`
+ * @returns {Promise<Object>}
+ */
+function stats (callback) {
+  const that = this;
+  if (is.fn(callback)) {
+    if (this._isStreamInput()) {
+      this.on('finish', function () {
+        that._flattenBufferIn();
+        sharp.stats(that.options, callback);
+      });
+    } else {
+      sharp.stats(this.options, callback);
+    }
+    return this;
+  } else {
+    if (this._isStreamInput()) {
+      return new Promise(function (resolve, reject) {
+        that.on('finish', function () {
+          that._flattenBufferIn();
+          sharp.stats(that.options, function (err, stats) {
+            if (err) {
+              reject(err);
+            } else {
+              resolve(stats);
+            }
+          });
+        });
+      });
+    } else {
+      return new Promise(function (resolve, reject) {
+        sharp.stats(that.options, function (err, stats) {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(stats);
+          }
+        });
+      });
+    }
+  }
+}
+
+/**
+ * Do not process input images where the number of pixels (width * height) exceeds this limit.
+ * Assumes image dimensions contained in the input metadata can be trusted.
+ * The default limit is 268402689 (0x3FFF * 0x3FFF) pixels.
+ * @param {(Number|Boolean)} limit - an integral Number of pixels, zero or false to remove limit, true to use default limit.
+ * @returns {Sharp}
+ * @throws {Error} Invalid limit
+*/
+function limitInputPixels (limit) {
+  // if we pass in false we represent the integer as 0 to disable
+  if (limit === false) {
+    limit = 0;
+  } else if (limit === true) {
+    limit = Math.pow(0x3FFF, 2);
+  }
+  if (is.integer(limit) && limit >= 0) {
+    this.options.limitInputPixels = limit;
+  } else {
+    throw is.invalidParameterError('limitInputPixels', 'integer', limit);
+  }
+  return this;
+}
+
+/**
+ * An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`.
+ * This will reduce memory usage and can improve performance on some systems.
+ *
+ * The default behaviour *before* function call is `false`, meaning the libvips access method is not sequential.
+ *
+ * @param {Boolean} [sequentialRead=true]
+ * @returns {Sharp}
+ */
+function sequentialRead (sequentialRead) {
+  this.options.sequentialRead = is.bool(sequentialRead) ? sequentialRead : true;
+  return this;
+}
+
+/**
+ * Decorate the Sharp prototype with input-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  Object.assign(Sharp.prototype, {
+    // Private
+    _createInputDescriptor,
+    _write,
+    _flattenBufferIn,
+    _isStreamInput,
+    // Public
+    clone,
+    metadata,
+    stats,
+    limitInputPixels,
+    sequentialRead
+  });
+};

lib/is.js

@@ -0,0 +1,119 @@
+'use strict';
+
+/**
+ * Is this value defined and not null?
+ * @private
+ */
+const defined = function (val) {
+  return typeof val !== 'undefined' && val !== null;
+};
+
+/**
+ * Is this value an object?
+ * @private
+ */
+const object = function (val) {
+  return typeof val === 'object';
+};
+
+/**
+ * Is this value a plain object?
+ * @private
+ */
+const plainObject = function (val) {
+  return object(val) && Object.prototype.toString.call(val) === '[object Object]';
+};
+
+/**
+ * Is this value a function?
+ * @private
+ */
+const fn = function (val) {
+  return typeof val === 'function';
+};
+
+/**
+ * Is this value a boolean?
+ * @private
+ */
+const bool = function (val) {
+  return typeof val === 'boolean';
+};
+
+/**
+ * Is this value a Buffer object?
+ * @private
+ */
+const buffer = function (val) {
+  return object(val) && val instanceof Buffer;
+};
+
+/**
+ * Is this value a non-empty string?
+ * @private
+ */
+const string = function (val) {
+  return typeof val === 'string' && val.length > 0;
+};
+
+/**
+ * Is this value a real number?
+ * @private
+ */
+const number = function (val) {
+  return typeof val === 'number' && !Number.isNaN(val);
+};
+
+/**
+ * Is this value an integer?
+ * @private
+ */
+const integer = function (val) {
+  return number(val) && val % 1 === 0;
+};
+
+/**
+ * Is this value within an inclusive given range?
+ * @private
+ */
+const inRange = function (val, min, max) {
+  return val >= min && val <= max;
+};
+
+/**
+ * Is this value within the elements of an array?
+ * @private
+ */
+const inArray = function (val, list) {
+  return list.indexOf(val) !== -1;
+};
+
+/**
+ * Create an Error with a message relating to an invalid parameter.
+ *
+ * @param {String} name - parameter name.
+ * @param {String} expected - description of the type/value/range expected.
+ * @param {*} actual - the value received.
+ * @returns {Error} Containing the formatted message.
+ * @private
+ */
+const invalidParameterError = function (name, expected, actual) {
+  return new Error(
+    `Expected ${expected} for ${name} but received ${actual} of type ${typeof actual}`
+  );
+};
+
+module.exports = {
+  defined: defined,
+  object: object,
+  plainObject: plainObject,
+  fn: fn,
+  bool: bool,
+  buffer: buffer,
+  string: string,
+  number: number,
+  integer: integer,
+  inRange: inRange,
+  inArray: inArray,
+  invalidParameterError: invalidParameterError
+};

lib/libvips.js

@@ -0,0 +1,95 @@
+'use strict';
+
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const spawnSync = require('child_process').spawnSync;
+const semver = require('semver');
+const platform = require('./platform');
+
+const env = process.env;
+const minimumLibvipsVersion = env.npm_package_config_libvips || require('../package.json').config.libvips;
+
+const spawnSyncOptions = {
+  encoding: 'utf8',
+  shell: true
+};
+
+const mkdirSync = function (dirPath) {
+  try {
+    fs.mkdirSync(dirPath);
+  } catch (err) {
+    if (err.code !== 'EEXIST') {
+      throw err;
+    }
+  }
+};
+
+const cachePath = function () {
+  const npmCachePath = env.npm_config_cache || (env.APPDATA ? path.join(env.APPDATA, 'npm-cache') : path.join(os.homedir(), '.npm'));
+  mkdirSync(npmCachePath);
+  const libvipsCachePath = path.join(npmCachePath, '_libvips');
+  mkdirSync(libvipsCachePath);
+  return libvipsCachePath;
+};
+
+const globalLibvipsVersion = function () {
+  if (process.platform !== 'win32') {
+    const globalLibvipsVersion = spawnSync(`PKG_CONFIG_PATH="${pkgConfigPath()}" pkg-config --modversion vips-cpp`, spawnSyncOptions).stdout || '';
+    return globalLibvipsVersion.trim();
+  } else {
+    return '';
+  }
+};
+
+const hasVendoredLibvips = function () {
+  const currentPlatformId = platform();
+  const vendorPath = path.join(__dirname, '..', 'vendor');
+  let vendorVersionId;
+  let vendorPlatformId;
+  try {
+    vendorVersionId = require(path.join(vendorPath, 'versions.json')).vips;
+    vendorPlatformId = require(path.join(vendorPath, 'platform.json'));
+  } catch (err) {}
+  if (vendorVersionId && vendorVersionId !== minimumLibvipsVersion) {
+    throw new Error(`Found vendored libvips v${vendorVersionId} but require v${minimumLibvipsVersion}. Please remove the 'node_modules/sharp/vendor' directory and run 'npm install'.`);
+  }
+  if (vendorPlatformId) {
+    if (currentPlatformId === vendorPlatformId) {
+      return true;
+    } else {
+      throw new Error(`'${vendorPlatformId}' binaries cannot be used on the '${currentPlatformId}' platform. Please remove the 'node_modules/sharp/vendor' directory and run 'npm install'.`);
+    }
+  }
+  return false;
+};
+
+const pkgConfigPath = function () {
+  if (process.platform !== 'win32') {
+    const brewPkgConfigPath = spawnSync('which brew >/dev/null 2>&1 && eval $(brew --env) && echo $PKG_CONFIG_LIBDIR', spawnSyncOptions).stdout || '';
+    return [brewPkgConfigPath.trim(), env.PKG_CONFIG_PATH, '/usr/local/lib/pkgconfig', '/usr/lib/pkgconfig']
+      .filter(function (p) { return !!p; })
+      .join(':');
+  } else {
+    return '';
+  }
+};
+
+const useGlobalLibvips = function () {
+  if (Boolean(env.SHARP_IGNORE_GLOBAL_LIBVIPS) === true) {
+    return false;
+  }
+
+  const globalVipsVersion = globalLibvipsVersion();
+  return !!globalVipsVersion && semver.gte(globalVipsVersion, minimumLibvipsVersion);
+};
+
+module.exports = {
+  minimumLibvipsVersion: minimumLibvipsVersion,
+  cachePath: cachePath,
+  globalLibvipsVersion: globalLibvipsVersion,
+  hasVendoredLibvips: hasVendoredLibvips,
+  pkgConfigPath: pkgConfigPath,
+  useGlobalLibvips: useGlobalLibvips,
+  mkdirSync: mkdirSync
+};

lib/operation.js

@@ -0,0 +1,441 @@
+'use strict';
+
+const color = require('color');
+const is = require('./is');
+
+/**
+ * Rotate the output image by either an explicit angle
+ * or auto-orient based on the EXIF `Orientation` tag.
+ *
+ * If an angle is provided, it is converted to a valid positive degree rotation.
+ * For example, `-450` will produce a 270deg rotation.
+ *
+ * When rotating by an angle other than a multiple of 90,
+ * the background colour can be provided with the `background` option.
+ *
+ * If no angle is provided, it is determined from the EXIF data.
+ * Mirroring is supported and may infer the use of a flip operation.
+ *
+ * The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
+ *
+ * Method order is important when both rotating and extracting regions,
+ * for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`.
+ *
+ * @example
+ * const pipeline = sharp()
+ *   .rotate()
+ *   .resize(null, 200)
+ *   .toBuffer(function (err, outputBuffer, info) {
+ *     // outputBuffer contains 200px high JPEG image data,
+ *     // auto-rotated using EXIF Orientation tag
+ *     // info.width and info.height contain the dimensions of the resized image
+ *   });
+ * readableStream.pipe(pipeline);
+ *
+ * @param {Number} [angle=auto] angle of rotation.
+ * @param {Object} [options] - if present, is an Object with optional attributes.
+ * @param {String|Object} [options.background="#000000"] parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function rotate (angle, options) {
+  if (!is.defined(angle)) {
+    this.options.useExifOrientation = true;
+  } else if (is.integer(angle) && !(angle % 90)) {
+    this.options.angle = angle;
+  } else if (is.number(angle)) {
+    this.options.rotationAngle = angle;
+    if (is.object(options) && options.background) {
+      const backgroundColour = color(options.background);
+      this.options.rotationBackground = [
+        backgroundColour.red(),
+        backgroundColour.green(),
+        backgroundColour.blue(),
+        Math.round(backgroundColour.alpha() * 255)
+      ];
+    }
+  } else {
+    throw new Error('Unsupported angle: must be a number.');
+  }
+  return this;
+}
+
+/**
+ * Flip the image about the vertical Y axis. This always occurs after rotation, if any.
+ * The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
+ * @param {Boolean} [flip=true]
+ * @returns {Sharp}
+ */
+function flip (flip) {
+  this.options.flip = is.bool(flip) ? flip : true;
+  return this;
+}
+
+/**
+ * Flop the image about the horizontal X axis. This always occurs after rotation, if any.
+ * The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
+ * @param {Boolean} [flop=true]
+ * @returns {Sharp}
+ */
+function flop (flop) {
+  this.options.flop = is.bool(flop) ? flop : true;
+  return this;
+}
+
+/**
+ * Sharpen the image.
+ * When used without parameters, performs a fast, mild sharpen of the output image.
+ * When a `sigma` is provided, performs a slower, more accurate sharpen of the L channel in the LAB colour space.
+ * Separate control over the level of sharpening in "flat" and "jagged" areas is available.
+ *
+ * @param {Number} [sigma] - the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+ * @param {Number} [flat=1.0] - the level of sharpening to apply to "flat" areas.
+ * @param {Number} [jagged=2.0] - the level of sharpening to apply to "jagged" areas.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function sharpen (sigma, flat, jagged) {
+  if (!is.defined(sigma)) {
+    // No arguments: default to mild sharpen
+    this.options.sharpenSigma = -1;
+  } else if (is.bool(sigma)) {
+    // Boolean argument: apply mild sharpen?
+    this.options.sharpenSigma = sigma ? -1 : 0;
+  } else if (is.number(sigma) && is.inRange(sigma, 0.01, 10000)) {
+    // Numeric argument: specific sigma
+    this.options.sharpenSigma = sigma;
+    // Control over flat areas
+    if (is.defined(flat)) {
+      if (is.number(flat) && is.inRange(flat, 0, 10000)) {
+        this.options.sharpenFlat = flat;
+      } else {
+        throw new Error('Invalid sharpen level for flat areas (0.0 - 10000.0) ' + flat);
+      }
+    }
+    // Control over jagged areas
+    if (is.defined(jagged)) {
+      if (is.number(jagged) && is.inRange(jagged, 0, 10000)) {
+        this.options.sharpenJagged = jagged;
+      } else {
+        throw new Error('Invalid sharpen level for jagged areas (0.0 - 10000.0) ' + jagged);
+      }
+    }
+  } else {
+    throw new Error('Invalid sharpen sigma (0.01 - 10000) ' + sigma);
+  }
+  return this;
+}
+
+/**
+ * Apply median filter.
+ * When used without parameters the default window is 3x3.
+ * @param {Number} [size=3] square mask size: size x size
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function median (size) {
+  if (!is.defined(size)) {
+    // No arguments: default to 3x3
+    this.options.medianSize = 3;
+  } else if (is.integer(size) && is.inRange(size, 1, 1000)) {
+    // Numeric argument: specific sigma
+    this.options.medianSize = size;
+  } else {
+    throw new Error('Invalid median size ' + size);
+  }
+  return this;
+}
+
+/**
+ * Blur the image.
+ * When used without parameters, performs a fast, mild blur of the output image.
+ * When a `sigma` is provided, performs a slower, more accurate Gaussian blur.
+ * @param {Number} [sigma] a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function blur (sigma) {
+  if (!is.defined(sigma)) {
+    // No arguments: default to mild blur
+    this.options.blurSigma = -1;
+  } else if (is.bool(sigma)) {
+    // Boolean argument: apply mild blur?
+    this.options.blurSigma = sigma ? -1 : 0;
+  } else if (is.number(sigma) && is.inRange(sigma, 0.3, 1000)) {
+    // Numeric argument: specific sigma
+    this.options.blurSigma = sigma;
+  } else {
+    throw new Error('Invalid blur sigma (0.3 - 1000.0) ' + sigma);
+  }
+  return this;
+}
+
+/**
+ * Merge alpha transparency channel, if any, with a background.
+ * @param {Object} [options]
+ * @param {String|Object} [options.background={r: 0, g: 0, b: 0}] - background colour, parsed by the [color](https://www.npmjs.org/package/color) module, defaults to black.
+ * @returns {Sharp}
+ */
+function flatten (options) {
+  this.options.flatten = is.bool(options) ? options : true;
+  if (is.object(options)) {
+    this._setColourOption('flattenBackground', options.background);
+  }
+  return this;
+}
+
+/**
+ * Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma`
+ * then increasing the encoding (brighten) post-resize at a factor of `gamma`.
+ * This can improve the perceived brightness of a resized image in non-linear colour spaces.
+ * JPEG and WebP input images will not take advantage of the shrink-on-load performance optimisation
+ * when applying a gamma correction.
+ *
+ * Supply a second argument to use a different output gamma value, otherwise the first value is used in both cases.
+ *
+ * @param {Number} [gamma=2.2] value between 1.0 and 3.0.
+ * @param {Number} [gammaOut] value between 1.0 and 3.0. (optional, defaults to same as `gamma`)
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function gamma (gamma, gammaOut) {
+  if (!is.defined(gamma)) {
+    // Default gamma correction of 2.2 (sRGB)
+    this.options.gamma = 2.2;
+  } else if (is.number(gamma) && is.inRange(gamma, 1, 3)) {
+    this.options.gamma = gamma;
+  } else {
+    throw new Error('Invalid gamma correction (1.0 to 3.0) ' + gamma);
+  }
+  if (!is.defined(gammaOut)) {
+    // Default gamma correction for output is same as input
+    this.options.gammaOut = this.options.gamma;
+  } else if (is.number(gammaOut) && is.inRange(gammaOut, 1, 3)) {
+    this.options.gammaOut = gammaOut;
+  } else {
+    throw new Error('Invalid output gamma correction (1.0 to 3.0) ' + gammaOut);
+  }
+  return this;
+}
+
+/**
+ * Produce the "negative" of the image.
+ * @param {Boolean} [negate=true]
+ * @returns {Sharp}
+ */
+function negate (negate) {
+  this.options.negate = is.bool(negate) ? negate : true;
+  return this;
+}
+
+/**
+ * Enhance output image contrast by stretching its luminance to cover the full dynamic range.
+ * @param {Boolean} [normalise=true]
+ * @returns {Sharp}
+ */
+function normalise (normalise) {
+  this.options.normalise = is.bool(normalise) ? normalise : true;
+  return this;
+}
+
+/**
+ * Alternative spelling of normalise.
+ * @param {Boolean} [normalize=true]
+ * @returns {Sharp}
+ */
+function normalize (normalize) {
+  return this.normalise(normalize);
+}
+
+/**
+ * Convolve the image with the specified kernel.
+ *
+ * @example
+ * sharp(input)
+ *   .convolve({
+ *     width: 3,
+ *     height: 3,
+ *     kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1]
+ *   })
+ *   .raw()
+ *   .toBuffer(function(err, data, info) {
+ *     // data contains the raw pixel data representing the convolution
+ *     // of the input image with the horizontal Sobel operator
+ *   });
+ *
+ * @param {Object} kernel
+ * @param {Number} kernel.width - width of the kernel in pixels.
+ * @param {Number} kernel.height - width of the kernel in pixels.
+ * @param {Array<Number>} kernel.kernel - Array of length `width*height` containing the kernel values.
+ * @param {Number} [kernel.scale=sum] - the scale of the kernel in pixels.
+ * @param {Number} [kernel.offset=0] - the offset of the kernel in pixels.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function convolve (kernel) {
+  if (!is.object(kernel) || !Array.isArray(kernel.kernel) ||
+      !is.integer(kernel.width) || !is.integer(kernel.height) ||
+      !is.inRange(kernel.width, 3, 1001) || !is.inRange(kernel.height, 3, 1001) ||
+      kernel.height * kernel.width !== kernel.kernel.length
+  ) {
+    // must pass in a kernel
+    throw new Error('Invalid convolution kernel');
+  }
+  // Default scale is sum of kernel values
+  if (!is.integer(kernel.scale)) {
+    kernel.scale = kernel.kernel.reduce(function (a, b) {
+      return a + b;
+    }, 0);
+  }
+  // Clip scale to a minimum value of 1
+  if (kernel.scale < 1) {
+    kernel.scale = 1;
+  }
+  if (!is.integer(kernel.offset)) {
+    kernel.offset = 0;
+  }
+  this.options.convKernel = kernel;
+  return this;
+}
+
+/**
+ * Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
+ * @param {Number} [threshold=128] - a value in the range 0-255 representing the level at which the threshold will be applied.
+ * @param {Object} [options]
+ * @param {Boolean} [options.greyscale=true] - convert to single channel greyscale.
+ * @param {Boolean} [options.grayscale=true] - alternative spelling for greyscale.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function threshold (threshold, options) {
+  if (!is.defined(threshold)) {
+    this.options.threshold = 128;
+  } else if (is.bool(threshold)) {
+    this.options.threshold = threshold ? 128 : 0;
+  } else if (is.integer(threshold) && is.inRange(threshold, 0, 255)) {
+    this.options.threshold = threshold;
+  } else {
+    throw new Error('Invalid threshold (0 to 255) ' + threshold);
+  }
+  if (!is.object(options) || options.greyscale === true || options.grayscale === true) {
+    this.options.thresholdGrayscale = true;
+  } else {
+    this.options.thresholdGrayscale = false;
+  }
+  return this;
+}
+
+/**
+ * Perform a bitwise boolean operation with operand image.
+ *
+ * This operation creates an output image where each pixel is the result of
+ * the selected bitwise boolean `operation` between the corresponding pixels of the input images.
+ *
+ * @param {Buffer|String} operand - Buffer containing image data or String containing the path to an image file.
+ * @param {String} operator - one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+ * @param {Object} [options]
+ * @param {Object} [options.raw] - describes operand when using raw pixel data.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function boolean (operand, operator, options) {
+  this.options.boolean = this._createInputDescriptor(operand, options);
+  if (is.string(operator) && is.inArray(operator, ['and', 'or', 'eor'])) {
+    this.options.booleanOp = operator;
+  } else {
+    throw new Error('Invalid boolean operator ' + operator);
+  }
+  return this;
+}
+
+/**
+ * Apply the linear formula a * input + b to the image (levels adjustment)
+ * @param {Number} [a=1.0] multiplier
+ * @param {Number} [b=0.0] offset
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function linear (a, b) {
+  if (!is.defined(a)) {
+    this.options.linearA = 1.0;
+  } else if (is.number(a)) {
+    this.options.linearA = a;
+  } else {
+    throw new Error('Invalid linear transform multiplier ' + a);
+  }
+
+  if (!is.defined(b)) {
+    this.options.linearB = 0.0;
+  } else if (is.number(b)) {
+    this.options.linearB = b;
+  } else {
+    throw new Error('Invalid linear transform offset ' + b);
+  }
+
+  return this;
+}
+
+/**
+ * Recomb the image with the specified matrix.
+ *
+ * @example
+ * sharp(input)
+ *   .recomb([
+ *    [0.3588, 0.7044, 0.1368],
+ *    [0.2990, 0.5870, 0.1140],
+ *    [0.2392, 0.4696, 0.0912],
+ *   ])
+ *   .raw()
+ *   .toBuffer(function(err, data, info) {
+ *     // data contains the raw pixel data after applying the recomb
+ *     // With this example input, a sepia filter has been applied
+ *   });
+ *
+ * @param {Array<Array<Number>>} 3x3 Recombination matrix
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function recomb (inputMatrix) {
+  if (!Array.isArray(inputMatrix) || inputMatrix.length !== 3 ||
+      inputMatrix[0].length !== 3 ||
+      inputMatrix[1].length !== 3 ||
+      inputMatrix[2].length !== 3
+  ) {
+    // must pass in a kernel
+    throw new Error('Invalid Recomb Matrix');
+  }
+  this.options.recombMatrix = [
+    inputMatrix[0][0], inputMatrix[0][1], inputMatrix[0][2],
+    inputMatrix[1][0], inputMatrix[1][1], inputMatrix[1][2],
+    inputMatrix[2][0], inputMatrix[2][1], inputMatrix[2][2]
+  ].map(Number);
+  return this;
+}
+
+/**
+ * Decorate the Sharp prototype with operation-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  Object.assign(Sharp.prototype, {
+    rotate,
+    flip,
+    flop,
+    sharpen,
+    median,
+    blur,
+    flatten,
+    gamma,
+    negate,
+    normalise,
+    normalize,
+    convolve,
+    threshold,
+    boolean,
+    linear,
+    recomb
+  });
+};

lib/output.js

@@ -0,0 +1,732 @@
+'use strict';
+
+const is = require('./is');
+const sharp = require('../build/Release/sharp.node');
+
+/**
+ * Write output image data to a file.
+ *
+ * If an explicit output format is not selected, it will be inferred from the extension,
+ * with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
+ * Note that raw pixel data is only supported for buffer output.
+ *
+ * A `Promise` is returned when `callback` is not provided.
+ *
+ * @example
+ * sharp(input)
+ *   .toFile('output.png', (err, info) => { ... });
+ *
+ * @example
+ * sharp(input)
+ *   .toFile('output.png')
+ *   .then(info => { ... })
+ *   .catch(err => { ... });
+ *
+ * @param {String} fileOut - the path to write the image data to.
+ * @param {Function} [callback] - called on completion with two arguments `(err, info)`.
+ * `info` contains the output image `format`, `size` (bytes), `width`, `height`,
+ * `channels` and `premultiplied` (indicating if premultiplication was used).
+ * When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
+ * @returns {Promise<Object>} - when no callback is provided
+ * @throws {Error} Invalid parameters
+ */
+function toFile (fileOut, callback) {
+  if (!fileOut || fileOut.length === 0) {
+    const errOutputInvalid = new Error('Invalid output');
+    if (is.fn(callback)) {
+      callback(errOutputInvalid);
+    } else {
+      return Promise.reject(errOutputInvalid);
+    }
+  } else {
+    if (this.options.input.file === fileOut) {
+      const errOutputIsInput = new Error('Cannot use same file for input and output');
+      if (is.fn(callback)) {
+        callback(errOutputIsInput);
+      } else {
+        return Promise.reject(errOutputIsInput);
+      }
+    } else {
+      this.options.fileOut = fileOut;
+      return this._pipeline(callback);
+    }
+  }
+  return this;
+}
+
+/**
+ * Write output to a Buffer.
+ * JPEG, PNG, WebP, TIFF and RAW output are supported.
+ * By default, the format will match the input image, except GIF and SVG input which become PNG output.
+ *
+ * `callback`, if present, gets three arguments `(err, data, info)` where:
+ * - `err` is an error, if any.
+ * - `data` is the output image data.
+ * - `info` contains the output image `format`, `size` (bytes), `width`, `height`,
+ * `channels` and `premultiplied` (indicating if premultiplication was used).
+ * When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
+ *
+ * A `Promise` is returned when `callback` is not provided.
+ *
+ * @example
+ * sharp(input)
+ *   .toBuffer((err, data, info) => { ... });
+ *
+ * @example
+ * sharp(input)
+ *   .toBuffer()
+ *   .then(data => { ... })
+ *   .catch(err => { ... });
+ *
+ * @example
+ * sharp(input)
+ *   .toBuffer({ resolveWithObject: true })
+ *   .then(({ data, info }) => { ... })
+ *   .catch(err => { ... });
+ *
+ * @param {Object} [options]
+ * @param {Boolean} [options.resolveWithObject] Resolve the Promise with an Object containing `data` and `info` properties instead of resolving only with `data`.
+ * @param {Function} [callback]
+ * @returns {Promise<Buffer>} - when no callback is provided
+ */
+function toBuffer (options, callback) {
+  if (is.object(options)) {
+    if (is.bool(options.resolveWithObject)) {
+      this.options.resolveWithObject = options.resolveWithObject;
+    }
+  }
+  return this._pipeline(is.fn(options) ? options : callback);
+}
+
+/**
+ * Include all metadata (EXIF, XMP, IPTC) from the input image in the output image.
+ * The default behaviour, when `withMetadata` is not used, is to strip all metadata and convert to the device-independent sRGB colour space.
+ * This will also convert to and add a web-friendly sRGB ICC profile.
+ *
+ * @example
+ * sharp('input.jpg')
+ *   .withMetadata()
+ *   .toFile('output-with-metadata.jpg')
+ *   .then(info => { ... });
+ *
+ * @param {Object} [withMetadata]
+ * @param {Number} [withMetadata.orientation] value between 1 and 8, used to update the EXIF `Orientation` tag.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function withMetadata (withMetadata) {
+  this.options.withMetadata = is.bool(withMetadata) ? withMetadata : true;
+  if (is.object(withMetadata)) {
+    if (is.defined(withMetadata.orientation)) {
+      if (is.integer(withMetadata.orientation) && is.inRange(withMetadata.orientation, 1, 8)) {
+        this.options.withMetadataOrientation = withMetadata.orientation;
+      } else {
+        throw new Error('Invalid orientation (1 to 8) ' + withMetadata.orientation);
+      }
+    }
+  }
+  return this;
+}
+
+/**
+ * Use these JPEG options for output image.
+ *
+ * @example
+ * // Convert any input to very high quality JPEG output
+ * const data = await sharp(input)
+ *   .jpeg({
+ *     quality: 100,
+ *     chromaSubsampling: '4:4:4'
+ *   })
+ *   .toBuffer();
+ *
+ * @param {Object} [options] - output options
+ * @param {Number} [options.quality=80] - quality, integer 1-100
+ * @param {Boolean} [options.progressive=false] - use progressive (interlace) scan
+ * @param {String} [options.chromaSubsampling='4:2:0'] - set to '4:4:4' to prevent chroma subsampling when quality <= 90
+ * @param {Boolean} [options.trellisQuantisation=false] - apply trellis quantisation, requires mozjpeg
+ * @param {Boolean} [options.overshootDeringing=false] - apply overshoot deringing, requires mozjpeg
+ * @param {Boolean} [options.optimiseScans=false] - optimise progressive scans, forces progressive, requires mozjpeg
+ * @param {Boolean} [options.optimizeScans=false] - alternative spelling of optimiseScans
+ * @param {Boolean} [options.optimiseCoding=true] - optimise Huffman coding tables
+ * @param {Boolean} [options.optimizeCoding=true] - alternative spelling of optimiseCoding
+ * @param {Number} [options.quantisationTable=0] - quantization table to use, integer 0-8, requires mozjpeg
+ * @param {Number} [options.quantizationTable=0] - alternative spelling of quantisationTable
+ * @param {Boolean} [options.force=true] - force JPEG output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+function jpeg (options) {
+  if (is.object(options)) {
+    if (is.defined(options.quality)) {
+      if (is.integer(options.quality) && is.inRange(options.quality, 1, 100)) {
+        this.options.jpegQuality = options.quality;
+      } else {
+        throw new Error('Invalid quality (integer, 1-100) ' + options.quality);
+      }
+    }
+    if (is.defined(options.progressive)) {
+      this._setBooleanOption('jpegProgressive', options.progressive);
+    }
+    if (is.defined(options.chromaSubsampling)) {
+      if (is.string(options.chromaSubsampling) && is.inArray(options.chromaSubsampling, ['4:2:0', '4:4:4'])) {
+        this.options.jpegChromaSubsampling = options.chromaSubsampling;
+      } else {
+        throw new Error('Invalid chromaSubsampling (4:2:0, 4:4:4) ' + options.chromaSubsampling);
+      }
+    }
+    const trellisQuantisation = is.bool(options.trellisQuantization) ? options.trellisQuantization : options.trellisQuantisation;
+    if (is.defined(trellisQuantisation)) {
+      this._setBooleanOption('jpegTrellisQuantisation', trellisQuantisation);
+    }
+    if (is.defined(options.overshootDeringing)) {
+      this._setBooleanOption('jpegOvershootDeringing', options.overshootDeringing);
+    }
+    const optimiseScans = is.bool(options.optimizeScans) ? options.optimizeScans : options.optimiseScans;
+    if (is.defined(optimiseScans)) {
+      this._setBooleanOption('jpegOptimiseScans', optimiseScans);
+      if (optimiseScans) {
+        this.options.jpegProgressive = true;
+      }
+    }
+    const optimiseCoding = is.bool(options.optimizeCoding) ? options.optimizeCoding : options.optimiseCoding;
+    if (is.defined(optimiseCoding)) {
+      this._setBooleanOption('jpegOptimiseCoding', optimiseCoding);
+    }
+    const quantisationTable = is.number(options.quantizationTable) ? options.quantizationTable : options.quantisationTable;
+    if (is.defined(quantisationTable)) {
+      if (is.integer(quantisationTable) && is.inRange(quantisationTable, 0, 8)) {
+        this.options.jpegQuantisationTable = quantisationTable;
+      } else {
+        throw new Error('Invalid quantisation table (integer, 0-8) ' + quantisationTable);
+      }
+    }
+  }
+  return this._updateFormatOut('jpeg', options);
+}
+
+/**
+ * Use these PNG options for output image.
+ *
+ * PNG output is always full colour at 8 or 16 bits per pixel.
+ * Indexed PNG input at 1, 2 or 4 bits per pixel is converted to 8 bits per pixel.
+ *
+ * @example
+ * // Convert any input to PNG output
+ * const data = await sharp(input)
+ *   .png()
+ *   .toBuffer();
+ *
+ * @param {Object} [options]
+ * @param {Boolean} [options.progressive=false] - use progressive (interlace) scan
+ * @param {Number} [options.compressionLevel=9] - zlib compression level, 0-9
+ * @param {Boolean} [options.adaptiveFiltering=false] - use adaptive row filtering
+ * @param {Boolean} [options.palette=false] - quantise to a palette-based image with alpha transparency support, requires libimagequant
+ * @param {Number} [options.quality=100] - use the lowest number of colours needed to achieve given quality, requires libimagequant
+ * @param {Number} [options.colours=256] - maximum number of palette entries, requires libimagequant
+ * @param {Number} [options.colors=256] - alternative spelling of `options.colours`, requires libimagequant
+ * @param {Number} [options.dither=1.0] - level of Floyd-Steinberg error diffusion, requires libimagequant
+ * @param {Boolean} [options.force=true] - force PNG output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+function png (options) {
+  if (is.object(options)) {
+    if (is.defined(options.progressive)) {
+      this._setBooleanOption('pngProgressive', options.progressive);
+    }
+    if (is.defined(options.compressionLevel)) {
+      if (is.integer(options.compressionLevel) && is.inRange(options.compressionLevel, 0, 9)) {
+        this.options.pngCompressionLevel = options.compressionLevel;
+      } else {
+        throw new Error('Invalid compressionLevel (integer, 0-9) ' + options.compressionLevel);
+      }
+    }
+    if (is.defined(options.adaptiveFiltering)) {
+      this._setBooleanOption('pngAdaptiveFiltering', options.adaptiveFiltering);
+    }
+    if (is.defined(options.palette)) {
+      this._setBooleanOption('pngPalette', options.palette);
+      if (this.options.pngPalette) {
+        if (is.defined(options.quality)) {
+          if (is.integer(options.quality) && is.inRange(options.quality, 0, 100)) {
+            this.options.pngQuality = options.quality;
+          } else {
+            throw is.invalidParameterError('quality', 'integer between 0 and 100', options.quality);
+          }
+        }
+        const colours = options.colours || options.colors;
+        if (is.defined(colours)) {
+          if (is.integer(colours) && is.inRange(colours, 2, 256)) {
+            this.options.pngColours = colours;
+          } else {
+            throw is.invalidParameterError('colours', 'integer between 2 and 256', colours);
+          }
+        }
+        if (is.defined(options.dither)) {
+          if (is.number(options.dither) && is.inRange(options.dither, 0, 1)) {
+            this.options.pngDither = options.dither;
+          } else {
+            throw is.invalidParameterError('dither', 'number between 0.0 and 1.0', options.dither);
+          }
+        }
+      }
+    }
+  }
+  return this._updateFormatOut('png', options);
+}
+
+/**
+ * Use these WebP options for output image.
+ *
+ * @example
+ * // Convert any input to lossless WebP output
+ * const data = await sharp(input)
+ *   .webp({ lossless: true })
+ *   .toBuffer();
+ *
+ * @param {Object} [options] - output options
+ * @param {Number} [options.quality=80] - quality, integer 1-100
+ * @param {Number} [options.alphaQuality=100] - quality of alpha layer, integer 0-100
+ * @param {Boolean} [options.lossless=false] - use lossless compression mode
+ * @param {Boolean} [options.nearLossless=false] - use near_lossless compression mode
+ * @param {Boolean} [options.force=true] - force WebP output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+function webp (options) {
+  if (is.object(options) && is.defined(options.quality)) {
+    if (is.integer(options.quality) && is.inRange(options.quality, 1, 100)) {
+      this.options.webpQuality = options.quality;
+    } else {
+      throw new Error('Invalid quality (integer, 1-100) ' + options.quality);
+    }
+  }
+  if (is.object(options) && is.defined(options.alphaQuality)) {
+    if (is.integer(options.alphaQuality) && is.inRange(options.alphaQuality, 0, 100)) {
+      this.options.webpAlphaQuality = options.alphaQuality;
+    } else {
+      throw new Error('Invalid webp alpha quality (integer, 0-100) ' + options.alphaQuality);
+    }
+  }
+  if (is.object(options) && is.defined(options.lossless)) {
+    this._setBooleanOption('webpLossless', options.lossless);
+  }
+  if (is.object(options) && is.defined(options.nearLossless)) {
+    this._setBooleanOption('webpNearLossless', options.nearLossless);
+  }
+  return this._updateFormatOut('webp', options);
+}
+
+/**
+ * Use these TIFF options for output image.
+ *
+ * @example
+ * // Convert SVG input to LZW-compressed, 1 bit per pixel TIFF output
+ * sharp('input.svg')
+ *   .tiff({
+ *     compression: 'lzw',
+ *     squash: true
+ *   })
+ *   .toFile('1-bpp-output.tiff')
+ *   .then(info => { ... });
+ *
+ * @param {Object} [options] - output options
+ * @param {Number} [options.quality=80] - quality, integer 1-100
+ * @param {Boolean} [options.force=true] - force TIFF output, otherwise attempt to use input format
+ * @param {Boolean} [options.compression='jpeg'] - compression options: lzw, deflate, jpeg, ccittfax4
+ * @param {Boolean} [options.predictor='horizontal'] - compression predictor options: none, horizontal, float
+ * @param {Boolean} [options.pyramid=false] - write an image pyramid
+ * @param {Boolean} [options.tile=false] - write a tiled tiff
+ * @param {Boolean} [options.tileWidth=256] - horizontal tile size
+ * @param {Boolean} [options.tileHeight=256] - vertical tile size
+ * @param {Number} [options.xres=1.0] - horizontal resolution in pixels/mm
+ * @param {Number} [options.yres=1.0] - vertical resolution in pixels/mm
+ * @param {Boolean} [options.squash=false] - squash 8-bit images down to 1 bit
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+function tiff (options) {
+  if (is.object(options)) {
+    if (is.defined(options.quality)) {
+      if (is.integer(options.quality) && is.inRange(options.quality, 1, 100)) {
+        this.options.tiffQuality = options.quality;
+      } else {
+        throw new Error('Invalid quality (integer, 1-100) ' + options.quality);
+      }
+    }
+    if (is.defined(options.squash)) {
+      if (is.bool(options.squash)) {
+        this.options.tiffSquash = options.squash;
+      } else {
+        throw new Error('Invalid Value for squash ' + options.squash + ' Only Boolean Values allowed for options.squash.');
+      }
+    }
+    // tiling
+    if (is.defined(options.tile)) {
+      if (is.bool(options.tile)) {
+        this.options.tiffTile = options.tile;
+      } else {
+        throw new Error('Invalid Value for tile ' + options.tile + ' Only Boolean values allowed for options.tile');
+      }
+    }
+    if (is.defined(options.tileWidth)) {
+      if (is.number(options.tileWidth) && options.tileWidth > 0) {
+        this.options.tiffTileWidth = options.tileWidth;
+      } else {
+        throw new Error('Invalid Value for tileWidth ' + options.tileWidth + ' Only positive numeric values allowed for options.tileWidth');
+      }
+    }
+    if (is.defined(options.tileHeight)) {
+      if (is.number(options.tileHeight) && options.tileHeight > 0) {
+        this.options.tiffTileHeight = options.tileHeight;
+      } else {
+        throw new Error('Invalid Value for tileHeight ' + options.tileHeight + ' Only positive numeric values allowed for options.tileHeight');
+      }
+    }
+    // pyramid
+    if (is.defined(options.pyramid)) {
+      if (is.bool(options.pyramid)) {
+        this.options.tiffPyramid = options.pyramid;
+      } else {
+        throw new Error('Invalid Value for pyramid ' + options.pyramid + ' Only Boolean values allowed for options.pyramid');
+      }
+    }
+    // resolution
+    if (is.defined(options.xres)) {
+      if (is.number(options.xres)) {
+        this.options.tiffXres = options.xres;
+      } else {
+        throw new Error('Invalid Value for xres ' + options.xres + ' Only numeric values allowed for options.xres');
+      }
+    }
+    if (is.defined(options.yres)) {
+      if (is.number(options.yres)) {
+        this.options.tiffYres = options.yres;
+      } else {
+        throw new Error('Invalid Value for yres ' + options.yres + ' Only numeric values allowed for options.yres');
+      }
+    }
+    // compression
+    if (is.defined(options.compression)) {
+      if (is.string(options.compression) && is.inArray(options.compression, ['lzw', 'deflate', 'jpeg', 'ccittfax4', 'none'])) {
+        this.options.tiffCompression = options.compression;
+      } else {
+        const message = `Invalid compression option "${options.compression}". Should be one of: lzw, deflate, jpeg, ccittfax4, none`;
+        throw new Error(message);
+      }
+    }
+    // predictor
+    if (is.defined(options.predictor)) {
+      if (is.string(options.predictor) && is.inArray(options.predictor, ['none', 'horizontal', 'float'])) {
+        this.options.tiffPredictor = options.predictor;
+      } else {
+        const message = `Invalid predictor option "${options.predictor}". Should be one of: none, horizontal, float`;
+        throw new Error(message);
+      }
+    }
+  }
+  return this._updateFormatOut('tiff', options);
+}
+
+/**
+ * Force output to be raw, uncompressed uint8 pixel data.
+ *
+ * @example
+ * // Extract raw RGB pixel data from JPEG input
+ * const { data, info } = await sharp('input.jpg')
+ *   .raw()
+ *   .toBuffer({ resolveWithObject: true });
+ *
+ * @returns {Sharp}
+ */
+function raw () {
+  return this._updateFormatOut('raw');
+}
+
+/**
+ * Force output to a given format.
+ *
+ * @example
+ * // Convert any input to PNG output
+ * const data = await sharp(input)
+ *   .toFormat('png')
+ *   .toBuffer();
+ *
+ * @param {(String|Object)} format - as a String or an Object with an 'id' attribute
+ * @param {Object} options - output options
+ * @returns {Sharp}
+ * @throws {Error} unsupported format or options
+ */
+function toFormat (format, options) {
+  if (is.object(format) && is.string(format.id)) {
+    format = format.id;
+  }
+  if (format === 'jpg') format = 'jpeg';
+  if (!is.inArray(format, ['jpeg', 'png', 'webp', 'tiff', 'raw'])) {
+    throw new Error('Unsupported output format ' + format);
+  }
+  return this[format](options);
+}
+
+/**
+ * Use tile-based deep zoom (image pyramid) output.
+ * Set the format and options for tile images via the `toFormat`, `jpeg`, `png` or `webp` functions.
+ * Use a `.zip` or `.szi` file extension with `toFile` to write to a compressed archive file format.
+ *
+ * Warning: multiple sharp instances concurrently producing tile output can expose a possible race condition in some versions of libgsf.
+ *
+ * @example
+ *  sharp('input.tiff')
+ *   .png()
+ *   .tile({
+ *     size: 512
+ *   })
+ *   .toFile('output.dz', function(err, info) {
+ *     // output.dzi is the Deep Zoom XML definition
+ *     // output_files contains 512x512 tiles grouped by zoom level
+ *   });
+ *
+ * @param {Object} [tile]
+ * @param {Number} [tile.size=256] tile size in pixels, a value between 1 and 8192.
+ * @param {Number} [tile.overlap=0] tile overlap in pixels, a value between 0 and 8192.
+ * @param {Number} [tile.angle=0] tile angle of rotation, must be a multiple of 90.
+ * @param {String} [tile.depth] how deep to make the pyramid, possible values are `onepixel`, `onetile` or `one`, default based on layout.
+ * @param {String} [tile.container='fs'] tile container, with value `fs` (filesystem) or `zip` (compressed file).
+ * @param {String} [tile.layout='dz'] filesystem layout, possible values are `dz`, `zoomify` or `google`.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function tile (tile) {
+  if (is.object(tile)) {
+    // Size of square tiles, in pixels
+    if (is.defined(tile.size)) {
+      if (is.integer(tile.size) && is.inRange(tile.size, 1, 8192)) {
+        this.options.tileSize = tile.size;
+      } else {
+        throw new Error('Invalid tile size (1 to 8192) ' + tile.size);
+      }
+    }
+    // Overlap of tiles, in pixels
+    if (is.defined(tile.overlap)) {
+      if (is.integer(tile.overlap) && is.inRange(tile.overlap, 0, 8192)) {
+        if (tile.overlap > this.options.tileSize) {
+          throw new Error('Tile overlap ' + tile.overlap + ' cannot be larger than tile size ' + this.options.tileSize);
+        }
+        this.options.tileOverlap = tile.overlap;
+      } else {
+        throw new Error('Invalid tile overlap (0 to 8192) ' + tile.overlap);
+      }
+    }
+    // Container
+    if (is.defined(tile.container)) {
+      if (is.string(tile.container) && is.inArray(tile.container, ['fs', 'zip'])) {
+        this.options.tileContainer = tile.container;
+      } else {
+        throw new Error('Invalid tile container ' + tile.container);
+      }
+    }
+    // Layout
+    if (is.defined(tile.layout)) {
+      if (is.string(tile.layout) && is.inArray(tile.layout, ['dz', 'google', 'zoomify'])) {
+        this.options.tileLayout = tile.layout;
+      } else {
+        throw new Error('Invalid tile layout ' + tile.layout);
+      }
+    }
+
+    // Angle of rotation,
+    if (is.defined(tile.angle)) {
+      if (is.integer(tile.angle) && !(tile.angle % 90)) {
+        this.options.tileAngle = tile.angle;
+      } else {
+        throw new Error('Unsupported angle: angle must be a positive/negative multiple of 90 ' + tile.angle);
+      }
+    }
+
+    // Depth of tiles
+    if (is.defined(tile.depth)) {
+      if (is.string(tile.depth) && is.inArray(tile.depth, ['onepixel', 'onetile', 'one'])) {
+        this.options.tileDepth = tile.depth;
+      } else {
+        throw new Error("Invalid tile depth '" + tile.depth + "', should be one of 'onepixel', 'onetile' or 'one'");
+      }
+    }
+  }
+  // Format
+  if (is.inArray(this.options.formatOut, ['jpeg', 'png', 'webp'])) {
+    this.options.tileFormat = this.options.formatOut;
+  } else if (this.options.formatOut !== 'input') {
+    throw new Error('Invalid tile format ' + this.options.formatOut);
+  }
+
+  return this._updateFormatOut('dz');
+}
+
+/**
+ * Update the output format unless options.force is false,
+ * in which case revert to input format.
+ * @private
+ * @param {String} formatOut
+ * @param {Object} [options]
+ * @param {Boolean} [options.force=true] - force output format, otherwise attempt to use input format
+ * @returns {Sharp}
+ */
+function _updateFormatOut (formatOut, options) {
+  if (!(is.object(options) && options.force === false)) {
+    this.options.formatOut = formatOut;
+  }
+  return this;
+}
+
+/**
+ * Update a Boolean attribute of the this.options Object.
+ * @private
+ * @param {String} key
+ * @param {Boolean} val
+ * @throws {Error} Invalid key
+ */
+function _setBooleanOption (key, val) {
+  if (is.bool(val)) {
+    this.options[key] = val;
+  } else {
+    throw new Error('Invalid ' + key + ' (boolean) ' + val);
+  }
+}
+
+/**
+ * Called by a WriteableStream to notify us it is ready for data.
+ * @private
+ */
+function _read () {
+  if (!this.options.streamOut) {
+    this.options.streamOut = true;
+    this._pipeline();
+  }
+}
+
+/**
+ * Invoke the C++ image processing pipeline
+ * Supports callback, stream and promise variants
+ * @private
+ */
+function _pipeline (callback) {
+  const that = this;
+  if (typeof callback === 'function') {
+    // output=file/buffer
+    if (this._isStreamInput()) {
+      // output=file/buffer, input=stream
+      this.on('finish', function () {
+        that._flattenBufferIn();
+        sharp.pipeline(that.options, callback);
+      });
+    } else {
+      // output=file/buffer, input=file/buffer
+      sharp.pipeline(this.options, callback);
+    }
+    return this;
+  } else if (this.options.streamOut) {
+    // output=stream
+    if (this._isStreamInput()) {
+      // output=stream, input=stream
+      if (this.streamInFinished) {
+        this._flattenBufferIn();
+        sharp.pipeline(this.options, function (err, data, info) {
+          if (err) {
+            that.emit('error', err);
+          } else {
+            that.emit('info', info);
+            that.push(data);
+          }
+          that.push(null);
+        });
+      } else {
+        this.on('finish', function () {
+          that._flattenBufferIn();
+          sharp.pipeline(that.options, function (err, data, info) {
+            if (err) {
+              that.emit('error', err);
+            } else {
+              that.emit('info', info);
+              that.push(data);
+            }
+            that.push(null);
+          });
+        });
+      }
+    } else {
+      // output=stream, input=file/buffer
+      sharp.pipeline(this.options, function (err, data, info) {
+        if (err) {
+          that.emit('error', err);
+        } else {
+          that.emit('info', info);
+          that.push(data);
+        }
+        that.push(null);
+      });
+    }
+    return this;
+  } else {
+    // output=promise
+    if (this._isStreamInput()) {
+      // output=promise, input=stream
+      return new Promise(function (resolve, reject) {
+        that.on('finish', function () {
+          that._flattenBufferIn();
+          sharp.pipeline(that.options, function (err, data, info) {
+            if (err) {
+              reject(err);
+            } else {
+              if (that.options.resolveWithObject) {
+                resolve({ data: data, info: info });
+              } else {
+                resolve(data);
+              }
+            }
+          });
+        });
+      });
+    } else {
+      // output=promise, input=file/buffer
+      return new Promise(function (resolve, reject) {
+        sharp.pipeline(that.options, function (err, data, info) {
+          if (err) {
+            reject(err);
+          } else {
+            if (that.options.resolveWithObject) {
+              resolve({ data: data, info: info });
+            } else {
+              resolve(data);
+            }
+          }
+        });
+      });
+    }
+  }
+}
+
+/**
+ * Decorate the Sharp prototype with output-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  Object.assign(Sharp.prototype, {
+    // Public
+    toFile,
+    toBuffer,
+    withMetadata,
+    jpeg,
+    png,
+    webp,
+    tiff,
+    raw,
+    toFormat,
+    tile,
+    // Private
+    _updateFormatOut,
+    _setBooleanOption,
+    _read,
+    _pipeline
+  });
+};

lib/platform.js

@@ -0,0 +1,18 @@
+'use strict';
+
+const detectLibc = require('detect-libc');
+
+module.exports = function () {
+  const arch = process.env.npm_config_arch || process.arch;
+  const platform = process.env.npm_config_platform || process.platform;
+  const libc = (platform === 'linux' && detectLibc.isNonGlibcLinux) ? detectLibc.family : '';
+
+  const platformId = [`${platform}${libc}`];
+  if (arch === 'arm' || arch === 'armhf' || arch === 'arm64') {
+    const armVersion = (arch === 'arm64') ? '8' : process.env.npm_config_armv || process.config.variables.arm_version || '6';
+    platformId.push(`armv${armVersion}`);
+  } else {
+    platformId.push(arch);
+  }
+  return platformId.join('-');
+};

lib/resize.js

@@ -0,0 +1,491 @@
+'use strict';
+
+const deprecate = require('util').deprecate;
+const is = require('./is');
+
+/**
+ * Weighting to apply when using contain/cover fit.
+ * @member
+ * @private
+ */
+const gravity = {
+  center: 0,
+  centre: 0,
+  north: 1,
+  east: 2,
+  south: 3,
+  west: 4,
+  northeast: 5,
+  southeast: 6,
+  southwest: 7,
+  northwest: 8
+};
+
+/**
+ * Position to apply when using contain/cover fit.
+ * @member
+ * @private
+ */
+const position = {
+  top: 1,
+  right: 2,
+  bottom: 3,
+  left: 4,
+  'right top': 5,
+  'right bottom': 6,
+  'left bottom': 7,
+  'left top': 8
+};
+
+/**
+ * Strategies for automagic cover behaviour.
+ * @member
+ * @private
+ */
+const strategy = {
+  entropy: 16,
+  attention: 17
+};
+
+/**
+ * Reduction kernels.
+ * @member
+ * @private
+ */
+const kernel = {
+  nearest: 'nearest',
+  cubic: 'cubic',
+  mitchell: 'mitchell',
+  lanczos2: 'lanczos2',
+  lanczos3: 'lanczos3'
+};
+
+/**
+ * Methods by which an image can be resized to fit the provided dimensions.
+ * @member
+ * @private
+ */
+const fit = {
+  contain: 'contain',
+  cover: 'cover',
+  fill: 'fill',
+  inside: 'inside',
+  outside: 'outside'
+};
+
+/**
+ * Map external fit property to internal canvas property.
+ * @member
+ * @private
+ */
+const mapFitToCanvas = {
+  contain: 'embed',
+  cover: 'crop',
+  fill: 'ignore_aspect',
+  inside: 'max',
+  outside: 'min'
+};
+
+/**
+ * Resize image to `width`, `height` or `width x height`.
+ *
+ * When both a `width` and `height` are provided, the possible methods by which the image should **fit** these are:
+ * - `cover`: Crop to cover both provided dimensions (the default).
+ * - `contain`: Embed within both provided dimensions.
+ * - `fill`: Ignore the aspect ratio of the input and stretch to both provided dimensions.
+ * - `inside`: Preserving aspect ratio, resize the image to be as large as possible while ensuring its dimensions are less than or equal to both those specified.
+ * - `outside`: Preserving aspect ratio, resize the image to be as small as possible while ensuring its dimensions are greater than or equal to both those specified.
+ * Some of these values are based on the [object-fit](https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit) CSS property.
+ *
+ * When using a `fit` of `cover` or `contain`, the default **position** is `centre`. Other options are:
+ * - `sharp.position`: `top`, `right top`, `right`, `right bottom`, `bottom`, `left bottom`, `left`, `left top`.
+ * - `sharp.gravity`: `north`, `northeast`, `east`, `southeast`, `south`, `southwest`, `west`, `northwest`, `center` or `centre`.
+ * - `sharp.strategy`: `cover` only, dynamically crop using either the `entropy` or `attention` strategy.
+ * Some of these values are based on the [object-position](https://developer.mozilla.org/en-US/docs/Web/CSS/object-position) CSS property.
+ *
+ * The experimental strategy-based approach resizes so one dimension is at its target length
+ * then repeatedly ranks edge regions, discarding the edge with the lowest score based on the selected strategy.
+ * - `entropy`: focus on the region with the highest [Shannon entropy](https://en.wikipedia.org/wiki/Entropy_%28information_theory%29).
+ * - `attention`: focus on the region with the highest luminance frequency, colour saturation and presence of skin tones.
+ *
+ * Possible interpolation kernels are:
+ * - `nearest`: Use [nearest neighbour interpolation](http://en.wikipedia.org/wiki/Nearest-neighbor_interpolation).
+ * - `cubic`: Use a [Catmull-Rom spline](https://en.wikipedia.org/wiki/Centripetal_Catmull%E2%80%93Rom_spline).
+ * - `mitchell`: Use a [Mitchell-Netravali spline](https://www.cs.utexas.edu/~fussell/courses/cs384g-fall2013/lectures/mitchell/Mitchell.pdf).
+ * - `lanczos2`: Use a [Lanczos kernel](https://en.wikipedia.org/wiki/Lanczos_resampling#Lanczos_kernel) with `a=2`.
+ * - `lanczos3`: Use a Lanczos kernel with `a=3` (the default).
+ *
+ * @example
+ * sharp(input)
+ *   .resize({ width: 100 })
+ *   .toBuffer()
+ *   .then(data => {
+ *     // 100 pixels wide, auto-scaled height
+ *   });
+ *
+ * @example
+ * sharp(input)
+ *   .resize({ height: 100 })
+ *   .toBuffer()
+ *   .then(data => {
+ *     // 100 pixels high, auto-scaled width
+ *   });
+ *
+ * @example
+ * sharp(input)
+ *   .resize(200, 300, {
+ *     kernel: sharp.kernel.nearest,
+ *     fit: 'contain',
+ *     position: 'right top',
+ *     background: { r: 255, g: 255, b: 255, alpha: 0.5 }
+ *   })
+ *   .toFile('output.png')
+ *   .then(() => {
+ *     // output.png is a 200 pixels wide and 300 pixels high image
+ *     // containing a nearest-neighbour scaled version
+ *     // contained within the north-east corner of a semi-transparent white canvas
+ *   });
+ *
+ * @example
+ * const transformer = sharp()
+ *   .resize({
+ *     width: 200,
+ *     height: 200,
+ *     fit: sharp.fit.cover,
+ *     position: sharp.strategy.entropy
+ *   });
+ * // Read image data from readableStream
+ * // Write 200px square auto-cropped image data to writableStream
+ * readableStream
+ *   .pipe(transformer)
+ *   .pipe(writableStream);
+ *
+ * @example
+ * sharp(input)
+ *   .resize(200, 200, {
+ *     fit: sharp.fit.inside,
+ *     withoutEnlargement: true
+ *   })
+ *   .toFormat('jpeg')
+ *   .toBuffer()
+ *   .then(function(outputBuffer) {
+ *     // outputBuffer contains JPEG image data
+ *     // no wider and no higher than 200 pixels
+ *     // and no larger than the input image
+ *   });
+ *
+ * @param {Number} [width] - pixels wide the resultant image should be. Use `null` or `undefined` to auto-scale the width to match the height.
+ * @param {Number} [height] - pixels high the resultant image should be. Use `null` or `undefined` to auto-scale the height to match the width.
+ * @param {Object} [options]
+ * @param {String} [options.width] - alternative means of specifying `width`. If both are present this take priority.
+ * @param {String} [options.height] - alternative means of specifying `height`. If both are present this take priority.
+ * @param {String} [options.fit='cover'] - how the image should be resized to fit both provided dimensions, one of `cover`, `contain`, `fill`, `inside` or `outside`.
+ * @param {String} [options.position='centre'] - position, gravity or strategy to use when `fit` is `cover` or `contain`.
+ * @param {String|Object} [options.background={r: 0, g: 0, b: 0, alpha: 1}] - background colour when using a `fit` of `contain`, parsed by the [color](https://www.npmjs.org/package/color) module, defaults to black without transparency.
+ * @param {String} [options.kernel='lanczos3'] - the kernel to use for image reduction.
+ * @param {Boolean} [options.withoutEnlargement=false] - do not enlarge if the width *or* height are already less than the specified dimensions, equivalent to GraphicsMagick's `>` geometry option.
+ * @param {Boolean} [options.fastShrinkOnLoad=true] - take greater advantage of the JPEG and WebP shrink-on-load feature, which can lead to a slight moiré pattern on some images.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function resize (width, height, options) {
+  if (is.defined(width)) {
+    if (is.object(width) && !is.defined(options)) {
+      options = width;
+    } else if (is.integer(width) && width > 0) {
+      this.options.width = width;
+    } else {
+      throw is.invalidParameterError('width', 'positive integer', width);
+    }
+  } else {
+    this.options.width = -1;
+  }
+  if (is.defined(height)) {
+    if (is.integer(height) && height > 0) {
+      this.options.height = height;
+    } else {
+      throw is.invalidParameterError('height', 'positive integer', height);
+    }
+  } else {
+    this.options.height = -1;
+  }
+  if (is.object(options)) {
+    // Width
+    if (is.integer(options.width) && options.width > 0) {
+      this.options.width = options.width;
+    }
+    // Height
+    if (is.integer(options.height) && options.height > 0) {
+      this.options.height = options.height;
+    }
+    // Fit
+    if (is.defined(options.fit)) {
+      const canvas = mapFitToCanvas[options.fit];
+      if (is.string(canvas)) {
+        this.options.canvas = canvas;
+      } else {
+        throw is.invalidParameterError('fit', 'valid fit', options.fit);
+      }
+    }
+    // Position
+    if (is.defined(options.position)) {
+      const pos = is.integer(options.position)
+        ? options.position
+        : strategy[options.position] || position[options.position] || gravity[options.position];
+      if (is.integer(pos) && (is.inRange(pos, 0, 8) || is.inRange(pos, 16, 17))) {
+        this.options.position = pos;
+      } else {
+        throw is.invalidParameterError('position', 'valid position/gravity/strategy', options.position);
+      }
+    }
+    // Background
+    if (is.defined(options.background)) {
+      this._setColourOption('resizeBackground', options.background);
+    }
+    // Kernel
+    if (is.defined(options.kernel)) {
+      if (is.string(kernel[options.kernel])) {
+        this.options.kernel = kernel[options.kernel];
+      } else {
+        throw is.invalidParameterError('kernel', 'valid kernel name', options.kernel);
+      }
+    }
+    // Without enlargement
+    if (is.defined(options.withoutEnlargement)) {
+      this._setBooleanOption('withoutEnlargement', options.withoutEnlargement);
+    }
+    // Shrink on load
+    if (is.defined(options.fastShrinkOnLoad)) {
+      this._setBooleanOption('fastShrinkOnLoad', options.fastShrinkOnLoad);
+    }
+  }
+  return this;
+}
+
+/**
+ * Extends/pads the edges of the image with the provided background colour.
+ * This operation will always occur after resizing and extraction, if any.
+ *
+ * @example
+ * // Resize to 140 pixels wide, then add 10 transparent pixels
+ * // to the top, left and right edges and 20 to the bottom edge
+ * sharp(input)
+ *   .resize(140)
+ *   .extend({
+ *     top: 10,
+ *     bottom: 20,
+ *     left: 10,
+ *     right: 10
+ *     background: { r: 0, g: 0, b: 0, alpha: 0 }
+ *   })
+ *   ...
+ *
+ * @param {(Number|Object)} extend - single pixel count to add to all edges or an Object with per-edge counts
+ * @param {Number} [extend.top]
+ * @param {Number} [extend.left]
+ * @param {Number} [extend.bottom]
+ * @param {Number} [extend.right]
+ * @param {String|Object} [extend.background={r: 0, g: 0, b: 0, alpha: 1}] - background colour, parsed by the [color](https://www.npmjs.org/package/color) module, defaults to black without transparency.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+*/
+function extend (extend) {
+  if (is.integer(extend) && extend > 0) {
+    this.options.extendTop = extend;
+    this.options.extendBottom = extend;
+    this.options.extendLeft = extend;
+    this.options.extendRight = extend;
+  } else if (
+    is.object(extend) &&
+    is.integer(extend.top) && extend.top >= 0 &&
+    is.integer(extend.bottom) && extend.bottom >= 0 &&
+    is.integer(extend.left) && extend.left >= 0 &&
+    is.integer(extend.right) && extend.right >= 0
+  ) {
+    this.options.extendTop = extend.top;
+    this.options.extendBottom = extend.bottom;
+    this.options.extendLeft = extend.left;
+    this.options.extendRight = extend.right;
+    this._setColourOption('extendBackground', extend.background);
+  } else {
+    throw new Error('Invalid edge extension ' + extend);
+  }
+  return this;
+}
+
+/**
+ * Extract a region of the image.
+ *
+ * - Use `extract` before `resize` for pre-resize extraction.
+ * - Use `extract` after `resize` for post-resize extraction.
+ * - Use `extract` before and after for both.
+ *
+ * @example
+ * sharp(input)
+ *   .extract({ left: left, top: top, width: width, height: height })
+ *   .toFile(output, function(err) {
+ *     // Extract a region of the input image, saving in the same format.
+ *   });
+ * @example
+ * sharp(input)
+ *   .extract({ left: leftOffsetPre, top: topOffsetPre, width: widthPre, height: heightPre })
+ *   .resize(width, height)
+ *   .extract({ left: leftOffsetPost, top: topOffsetPost, width: widthPost, height: heightPost })
+ *   .toFile(output, function(err) {
+ *     // Extract a region, resize, then extract from the resized image
+ *   });
+ *
+ * @param {Object} options
+ * @param {Number} options.left - zero-indexed offset from left edge
+ * @param {Number} options.top - zero-indexed offset from top edge
+ * @param {Number} options.width - dimension of extracted image
+ * @param {Number} options.height - dimension of extracted image
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function extract (options) {
+  const suffix = this.options.width === -1 && this.options.height === -1 ? 'Pre' : 'Post';
+  ['left', 'top', 'width', 'height'].forEach(function (name) {
+    const value = options[name];
+    if (is.integer(value) && value >= 0) {
+      this.options[name + (name === 'left' || name === 'top' ? 'Offset' : '') + suffix] = value;
+    } else {
+      throw new Error('Non-integer value for ' + name + ' of ' + value);
+    }
+  }, this);
+  // Ensure existing rotation occurs before pre-resize extraction
+  if (suffix === 'Pre' && ((this.options.angle % 360) !== 0 || this.options.useExifOrientation === true)) {
+    this.options.rotateBeforePreExtract = true;
+  }
+  return this;
+}
+
+/**
+ * Trim "boring" pixels from all edges that contain values similar to the top-left pixel.
+ * The `info` response Object will contain `trimOffsetLeft` and `trimOffsetTop` properties.
+ * @param {Number} [threshold=10] the allowed difference from the top-left pixel, a number greater than zero.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+function trim (threshold) {
+  if (!is.defined(threshold)) {
+    this.options.trimThreshold = 10;
+  } else if (is.number(threshold) && threshold > 0) {
+    this.options.trimThreshold = threshold;
+  } else {
+    throw is.invalidParameterError('threshold', 'number greater than zero', threshold);
+  }
+  return this;
+}
+
+// Deprecated functions
+
+/**
+ * @deprecated
+ * @private
+ */
+function crop (crop) {
+  this.options.canvas = 'crop';
+  if (!is.defined(crop)) {
+    // Default
+    this.options.position = gravity.center;
+  } else if (is.integer(crop) && is.inRange(crop, 0, 8)) {
+    // Gravity (numeric)
+    this.options.position = crop;
+  } else if (is.string(crop) && is.integer(gravity[crop])) {
+    // Gravity (string)
+    this.options.position = gravity[crop];
+  } else if (is.integer(crop) && crop >= strategy.entropy) {
+    // Strategy
+    this.options.position = crop;
+  } else if (is.string(crop) && is.integer(strategy[crop])) {
+    // Strategy (string)
+    this.options.position = strategy[crop];
+  } else {
+    throw is.invalidParameterError('crop', 'valid crop id/name/strategy', crop);
+  }
+  return this;
+}
+
+/**
+ * @deprecated
+ * @private
+ */
+function embed (embed) {
+  this.options.canvas = 'embed';
+  if (!is.defined(embed)) {
+    // Default
+    this.options.position = gravity.center;
+  } else if (is.integer(embed) && is.inRange(embed, 0, 8)) {
+    // Gravity (numeric)
+    this.options.position = embed;
+  } else if (is.string(embed) && is.integer(gravity[embed])) {
+    // Gravity (string)
+    this.options.position = gravity[embed];
+  } else {
+    throw is.invalidParameterError('embed', 'valid embed id/name', embed);
+  }
+  return this;
+}
+
+/**
+ * @deprecated
+ * @private
+ */
+function max () {
+  this.options.canvas = 'max';
+  return this;
+}
+
+/**
+ * @deprecated
+ * @private
+ */
+function min () {
+  this.options.canvas = 'min';
+  return this;
+}
+
+/**
+ * @deprecated
+ * @private
+ */
+function ignoreAspectRatio () {
+  this.options.canvas = 'ignore_aspect';
+  return this;
+}
+
+/**
+ * @deprecated
+ * @private
+*/
+function withoutEnlargement (withoutEnlargement) {
+  this.options.withoutEnlargement = is.bool(withoutEnlargement) ? withoutEnlargement : true;
+  return this;
+}
+
+/**
+ * Decorate the Sharp prototype with resize-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  Object.assign(Sharp.prototype, {
+    resize,
+    extend,
+    extract,
+    trim
+  });
+  // Class attributes
+  Sharp.gravity = gravity;
+  Sharp.strategy = strategy;
+  Sharp.kernel = kernel;
+  Sharp.fit = fit;
+  Sharp.position = position;
+  // Deprecated functions, to be removed in v0.22.0
+  Sharp.prototype.crop = deprecate(crop, 'crop(position) is deprecated, use resize({ fit: "cover", position }) instead');
+  Sharp.prototype.embed = deprecate(embed, 'embed(position) is deprecated, use resize({ fit: "contain", position }) instead');
+  Sharp.prototype.max = deprecate(max, 'max() is deprecated, use resize({ fit: "inside" }) instead');
+  Sharp.prototype.min = deprecate(min, 'min() is deprecated, use resize({ fit: "outside" }) instead');
+  Sharp.prototype.ignoreAspectRatio = deprecate(ignoreAspectRatio, 'ignoreAspectRatio() is deprecated, use resize({ fit: "fill" }) instead');
+  Sharp.prototype.withoutEnlargement = deprecate(withoutEnlargement, 'withoutEnlargement() is deprecated, use resize({ withoutEnlargement: true }) instead');
+};

lib/utility.js

@@ -0,0 +1,113 @@
+'use strict';
+
+const is = require('./is');
+const sharp = require('../build/Release/sharp.node');
+
+/**
+ * Gets or, when options are provided, sets the limits of _libvips'_ operation cache.
+ * Existing entries in the cache will be trimmed after any change in limits.
+ * This method always returns cache statistics,
+ * useful for determining how much working memory is required for a particular task.
+ *
+ * @example
+ * const stats = sharp.cache();
+ * @example
+ * sharp.cache( { items: 200 } );
+ * sharp.cache( { files: 0 } );
+ * sharp.cache(false);
+ *
+ * @param {Object|Boolean} [options=true] - Object with the following attributes, or Boolean where true uses default cache settings and false removes all caching
+ * @param {Number} [options.memory=50] - is the maximum memory in MB to use for this cache
+ * @param {Number} [options.files=20] - is the maximum number of files to hold open
+ * @param {Number} [options.items=100] - is the maximum number of operations to cache
+ * @returns {Object}
+ */
+function cache (options) {
+  if (is.bool(options)) {
+    if (options) {
+      // Default cache settings of 50MB, 20 files, 100 items
+      return sharp.cache(50, 20, 100);
+    } else {
+      return sharp.cache(0, 0, 0);
+    }
+  } else if (is.object(options)) {
+    return sharp.cache(options.memory, options.files, options.items);
+  } else {
+    return sharp.cache();
+  }
+}
+cache(true);
+
+/**
+ * Gets or, when a concurrency is provided, sets
+ * the number of threads _libvips'_ should create to process each image.
+ * The default value is the number of CPU cores.
+ * A value of `0` will reset to this default.
+ *
+ * The maximum number of images that can be processed in parallel
+ * is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
+ *
+ * This method always returns the current concurrency.
+ *
+ * @example
+ * const threads = sharp.concurrency(); // 4
+ * sharp.concurrency(2); // 2
+ * sharp.concurrency(0); // 4
+ *
+ * @param {Number} [concurrency]
+ * @returns {Number} concurrency
+ */
+function concurrency (concurrency) {
+  return sharp.concurrency(is.integer(concurrency) ? concurrency : null);
+}
+
+/**
+ * Provides access to internal task counters.
+ * - queue is the number of tasks this module has queued waiting for _libuv_ to provide a worker thread from its pool.
+ * - process is the number of resize tasks currently being processed.
+ *
+ * @example
+ * const counters = sharp.counters(); // { queue: 2, process: 4 }
+ *
+ * @returns {Object}
+ */
+function counters () {
+  return sharp.counters();
+}
+
+/**
+ * Get and set use of SIMD vector unit instructions.
+ * Requires libvips to have been compiled with liborc support.
+ *
+ * Improves the performance of `resize`, `blur` and `sharpen` operations
+ * by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM NEON.
+ *
+ * @example
+ * const simd = sharp.simd();
+ * // simd is `true` if the runtime use of liborc is currently enabled
+ * @example
+ * const simd = sharp.simd(false);
+ * // prevent libvips from using liborc at runtime
+ *
+ * @param {Boolean} [simd=true]
+ * @returns {Boolean}
+ */
+function simd (simd) {
+  return sharp.simd(is.bool(simd) ? simd : null);
+}
+simd(true);
+
+/**
+ * Decorate the Sharp class with utility-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  [
+    cache,
+    concurrency,
+    counters,
+    simd
+  ].forEach(function (f) {
+    Sharp[f.name] = f;
+  });
+};

mkdocs.yml

@@ -1,17 +1,27 @@
 site_name: sharp
-site_url: http://sharp.dimens.io/
+site_url: https://sharp.pixelplumbing.com/
 repo_url: https://github.com/lovell/sharp
-site_description: The fastest Node.js module for resizing JPEG, PNG, WebP and TIFF images. Uses the libvips library.
+site_description: High performance Node.js image processing, the fastest module to resize JPEG, PNG, WebP and TIFF images
-copyright: <a href="https://dimens.io/">dimens.io</a>
+copyright: <a href="https://pixelplumbing.com/">pixelplumbing.com</a>
-google_analytics: ['UA-13034748-12', 'sharp.dimens.io']
+google_analytics: ['UA-13034748-12', 'sharp.pixelplumbing.com']
 theme: readthedocs
+extra_css:
+  - css/extra.css
 markdown_extensions:
   - toc:
       permalink: True
-dev_addr: 0.0.0.0:10101
 pages:
   - Home: index.md
   - Installation: install.md
-  - API: api.md
+  - API:
+    - Constructor: api-constructor.md
+    - Input: api-input.md
+    - Output: api-output.md
+    - "Resizing images": api-resize.md
+    - "Compositing images": api-composite.md
+    - "Image operations": api-operation.md
+    - "Colour manipulation": api-colour.md
+    - "Channel manipulation": api-channel.md
+    - Utilities: api-utility.md
   - Performance: performance.md
   - Changelog: changelog.md

package.json

@@ -1,7 +1,9 @@
 {
   "name": "sharp",
-  "version": "0.14.1",
+  "description": "High performance Node.js image processing, the fastest module to resize JPEG, PNG, WebP and TIFF images",
+  "version": "0.21.2",
   "author": "Lovell Fuller <npm@lovell.info>",
+  "homepage": "https://github.com/lovell/sharp",
   "contributors": [
     "Pierre Inglebert <pierre.inglebert@gmail.com>",
     "Jonathan Ong <jonathanrichardong@gmail.com>",
@@ -22,18 +24,54 @@
     "John Tobin <john@limelightmobileinc.com>",
     "Kenton Gray <kentongray@gmail.com>",
     "Felix Bünemann <Felix.Buenemann@gmail.com>",
-    "Samy Al Zahrani <samyalzahrany@gmail.com>"
+    "Samy Al Zahrani <samyalzahrany@gmail.com>",
+    "Chintan Thakkar <lemnisk8@gmail.com>",
+    "F. Orlando Galashan <frulo@gmx.de>",
+    "Kleis Auke Wolthuizen <info@kleisauke.nl>",
+    "Matt Hirsch <mhirsch@media.mit.edu>",
+    "Matthias Thoemmes <thoemmes@gmail.com>",
+    "Patrick Paskaris <patrick@paskaris.gr>",
+    "Jérémy Lal <kapouer@melix.org>",
+    "Rahul Nanwani <r.nanwani@gmail.com>",
+    "Alice Monday <alice0meta@gmail.com>",
+    "Kristo Jorgenson <kristo.jorgenson@gmail.com>",
+    "YvesBos <yves_bos@outlook.com>",
+    "Guy Maliar <guy@tailorbrands.com>",
+    "Nicolas Coden <nicolas@ncoden.fr>",
+    "Matt Parrish <matt.r.parrish@gmail.com>",
+    "Marcel Bretschneider <marcel.bretschneider@gmail.com>",
+    "Matthew McEachen <matthew+github@mceachen.org>",
+    "Jarda Kotěšovec <jarda.kotesovec@gmail.com>",
+    "Kenric D'Souza <kenric.dsouza@gmail.com>",
+    "Oleh Aleinyk <oleg.aleynik@gmail.com>",
+    "Marcel Bretschneider <marcel.bretschneider@gmail.com>",
+    "Andrea Bianco <andrea.bianco@unibas.ch>",
+    "Rik Heywood <rik@rik.org>",
+    "Thomas Parisot <hi@oncletom.io>",
+    "Nathan Graves <nathanrgraves+github@gmail.com>",
+    "Tom Lokhorst <tom@lokhorst.eu>",
+    "Espen Hovlandsdal <espen@hovlandsdal.com>",
+    "Sylvain Dumont <sylvain.dumont35@gmail.com>",
+    "Alun Davies <alun.owain.davies@googlemail.com>",
+    "Aidan Hoolachan <ajhoolachan21@gmail.com>",
+    "Axel Eirola <axel.eirola@iki.fi>",
+    "Freezy <freezy@xbmc.org>",
+    "Daiz <taneli.vatanen@gmail.com>",
+    "Julian Aubourg <j@ubourg.net>",
+    "Keith Belovay <keith@picthrive.com>",
+    "Michael B. Klein <mbklein@gmail.com>"
   ],
-  "description": "High performance Node.js module to resize JPEG, PNG, WebP and TIFF images using the libvips library",
   "scripts": {
-    "clean": "rm -rf node_modules/ build/ include/ lib/ coverage/ test/fixtures/output.*",
+    "install": "(node install/libvips && node install/dll-copy && prebuild-install) || (node-gyp rebuild && node install/dll-copy)",
-    "test": "VIPS_WARNING=0 node ./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha -- --slow=5000 --timeout=30000 ./test/unit/*.js",
+    "clean": "rm -rf node_modules/ build/ vendor/ .nyc_output/ coverage/ test/fixtures/output.*",
-    "test-win": "node ./node_modules/mocha/bin/mocha --slow=5000 --timeout=60000 ./test/unit/*.js",
+    "test": "semistandard && cc && npm run test-unit && npm run test-licensing && prebuild-ci",
+    "test-unit": "nyc --reporter=lcov --branches=99 mocha --slow=5000 --timeout=60000 ./test/unit/*.js",
+    "test-licensing": "license-checker --production --summary --onlyAllow=\"Apache-2.0;BSD;ISC;MIT\"",
+    "test-coverage": "./test/coverage/report.sh",
     "test-leak": "./test/leak/leak.sh",
-    "test-packaging": "./packaging/test.sh",
+    "docs": "for m in constructor input resize composite operation colour channel output utility; do documentation build --shallow --format=md --markdown-toc=false lib/$m.js >docs/api-$m.md; done"
-    "test-clean": "rm -rf coverage/ test/fixtures/output.* && npm install && npm test"
   },
-  "main": "index.js",
+  "main": "lib/index.js",
   "repository": {
     "type": "git",
     "url": "git://github.com/lovell/sharp"
@@ -43,39 +81,65 @@
     "png",
     "webp",
     "tiff",
+    "gif",
+    "svg",
     "dzi",
+    "image",
     "resize",
     "thumbnail",
     "crop",
+    "embed",
     "libvips",
     "vips"
   ],
   "dependencies": {
-    "bluebird": "^3.3.5",
+    "bindings": "^1.3.1",
-    "color": "^0.11.1",
+    "color": "^3.1.0",
-    "nan": "^2.2.1",
+    "detect-libc": "^1.0.3",
-    "semver": "^5.1.0",
+    "fs-copy-file-sync": "^1.1.1",
-    "request": "^2.71.0",
+    "nan": "^2.12.1",
-    "tar": "^2.2.1"
+    "npmlog": "^4.1.2",
+    "prebuild-install": "^5.2.2",
+    "semver": "^5.6.0",
+    "simple-get": "^3.0.3",
+    "tar": "^4.4.8",
+    "tunnel-agent": "^0.6.0"
   },
   "devDependencies": {
-    "async": "^1.5.2",
+    "async": "^2.6.1",
-    "bufferutil": "^1.2.1",
+    "cc": "^1.0.2",
-    "coveralls": "^2.11.9",
+    "decompress-zip": "^0.3.1",
-    "exif-reader": "^1.0.0",
+    "documentation": "^9.1.1",
-    "icc": "^0.0.2",
+    "exif-reader": "^1.0.2",
-    "istanbul": "^0.4.3",
+    "icc": "^1.0.0",
-    "mocha": "^2.4.5",
+    "license-checker": "^25.0.1",
-    "mocha-jshint": "^2.3.1",
+    "mocha": "^5.2.0",
-    "node-cpplint": "^0.4.0",
+    "mock-fs": "^4.7.0",
-    "rimraf": "^2.5.2",
+    "nyc": "^13.1.0",
-    "unzip": "^0.1.11"
+    "prebuild": "^8.1.2",
+    "prebuild-ci": "^2.3.0",
+    "rimraf": "^2.6.3",
+    "semistandard": "^13.0.1"
   },
   "license": "Apache-2.0",
   "config": {
-    "libvips": "8.2.3"
+    "libvips": "8.7.0"
   },
   "engines": {
-    "node": ">=0.10"
+    "node": ">=6"
+  },
+  "semistandard": {
+    "env": [
+      "mocha"
+    ]
+  },
+  "cc": {
+    "linelength": "120",
+    "filter": [
+      "build/c++11",
+      "build/include",
+      "runtime/indentation_namespace",
+      "runtime/references"
+    ]
   }
 }

packaging/arm-build.sh

@@ -1,34 +0,0 @@
-#!/bin/sh
-
-if [ $# -lt 1 ]; then
-  echo "Usage: $0 IP"
-  echo "Build libvips for ARM using Docker, where IP is"
-  echo "the address of a Raspberry Pi running HypriotOS"
-  exit 1
-fi
-IP="$1"
-
-echo "Verifying connectivity to $IP"
-if ! ping -c 1 $IP; then
-  echo "Could not connect to $IP"
-  exit 1
-fi
-
-if ! type sshpass >/dev/null; then
-  echo "Please install sshpass"
-  exit 1
-fi
-
-export SSHPASS=hypriot
-
-echo "Copying arm/Dockerfile and arm/build.sh to device"
-sshpass -e scp -o PreferredAuthentications=password -r arm root@${IP}:/root
-
-echo "Building Raspbian-based container"
-sshpass -e ssh -o PreferredAuthentications=password -t root@${IP} "docker build -t vips-dev-arm arm"
-
-echo "Running arm/build.sh within container"
-sshpass -e ssh -o PreferredAuthentications=password -t root@${IP} "docker run -i -t --rm -v \${PWD}/arm:/arm vips-dev-arm sh -c 'cd /arm && ./build.sh' | tee arm/build.log"
-
-echo "Copying resultant tar.gz file from device"
-sshpass -e scp -o PreferredAuthentications=password root@${IP}:/root/arm/*.tar.gz .

packaging/arm-test.sh

@@ -1,28 +0,0 @@
-#!/bin/sh
-
-if [ $# -lt 1 ]; then
-  echo "Usage: $0 IP"
-  echo "Test sharp on ARM using Docker, where IP is"
-  echo "the address of a Raspberry Pi running HypriotOS"
-  exit 1
-fi
-IP="$1"
-
-echo "Verifying connectivity to $IP"
-if ! ping -c 1 $IP; then
-  echo "Could not connect to $IP"
-  exit 1
-fi
-
-if ! type sshpass >/dev/null; then
-  echo "Please install sshpass"
-  exit 1
-fi
-
-export SSHPASS=hypriot
-
-echo "Copying sharp source to device"
-sshpass -e scp -o PreferredAuthentications=password -r ../../sharp root@${IP}:/root/sharp
-
-echo "Compile and test within container"
-sshpass -e ssh -o PreferredAuthentications=password -t root@${IP} "docker run -i -t --rm -v \${PWD}/sharp:/s hypriot/rpi-node:5 sh -c 'cd /s && npm install --unsafe-perm && npm test'"

packaging/arm/Dockerfile

@@ -1,5 +0,0 @@
-FROM resin/rpi-raspbian:jessie
-MAINTAINER Lovell Fuller <npm@lovell.info>
-
-# Build dependencies
-RUN apt-get update && apt-get install -y build-essential autoconf libtool nasm gtk-doc-tools texinfo curl

packaging/arm/build.sh

@@ -1,137 +0,0 @@
-#!/bin/sh
-
-# To be run inside a Raspbian container
-
-# Working directories
-DEPS=/deps
-TARGET=/target
-mkdir ${DEPS}
-mkdir ${TARGET}
-
-# Common build paths and flags
-export PKG_CONFIG_PATH="${PKG_CONFIG_PATH}:${TARGET}/lib/pkgconfig"
-export PATH="${PATH}:${TARGET}/bin"
-export CPPFLAGS="-I${TARGET}/include"
-export LDFLAGS="-L${TARGET}/lib"
-export CFLAGS="-O3"
-export CXXFLAGS="-O3"
-
-# Dependency version numbers
-VERSION_ZLIB=1.2.8
-VERSION_FFI=3.2.1
-VERSION_GLIB=2.47.6
-VERSION_XML2=2.9.3
-VERSION_GSF=1.14.34
-VERSION_EXIF=0.6.21
-VERSION_LCMS2=2.7
-VERSION_GM=1.3.23
-VERSION_JPEG=1.4.2
-VERSION_PNG16=1.6.21
-VERSION_WEBP=0.5.0
-VERSION_TIFF=4.0.6
-VERSION_ORC=0.4.25
-VERSION_VIPS=8.2.3
-
-mkdir ${DEPS}/zlib
-curl -Ls http://zlib.net/zlib-${VERSION_ZLIB}.tar.xz | tar xJC ${DEPS}/zlib --strip-components=1
-cd ${DEPS}/zlib
-./configure --prefix=${TARGET} && make install
-rm ${TARGET}/lib/libz.a
-
-mkdir ${DEPS}/ffi
-curl -Ls ftp://sourceware.org/pub/libffi/libffi-${VERSION_FFI}.tar.gz | tar xzC ${DEPS}/ffi --strip-components=1
-cd ${DEPS}/ffi
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-builddir && make install-strip
-
-mkdir ${DEPS}/glib
-curl -Ls https://download.gnome.org/sources/glib/2.47/glib-${VERSION_GLIB}.tar.xz | tar xJC ${DEPS}/glib --strip-components=1
-cd ${DEPS}/glib
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --with-pcre=internal && make install-strip
-
-mkdir ${DEPS}/xml2
-curl -Ls http://xmlsoft.org/sources/libxml2-${VERSION_XML2}.tar.gz | tar xzC ${DEPS}/xml2 --strip-components=1
-cd ${DEPS}/xml2
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --without-python --with-zlib=${TARGET} && make install-strip
-
-mkdir ${DEPS}/gsf
-curl -Ls https://download.gnome.org/sources/libgsf/1.14/libgsf-${VERSION_GSF}.tar.xz | tar xJC ${DEPS}/gsf --strip-components=1
-cd ${DEPS}/gsf
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-mkdir ${DEPS}/exif
-curl -Ls http://heanet.dl.sourceforge.net/project/libexif/libexif/${VERSION_EXIF}/libexif-${VERSION_EXIF}.tar.bz2 | tar xjC ${DEPS}/exif --strip-components=1
-cd ${DEPS}/exif
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-mkdir ${DEPS}/lcms2
-curl -Ls http://heanet.dl.sourceforge.net/project/lcms/lcms/${VERSION_LCMS2}/lcms2-${VERSION_LCMS2}.tar.gz | tar xzC ${DEPS}/lcms2 --strip-components=1
-cd ${DEPS}/lcms2
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-mkdir ${DEPS}/gm
-curl -Ls http://heanet.dl.sourceforge.net/project/graphicsmagick/graphicsmagick/${VERSION_GM}/GraphicsMagick-${VERSION_GM}.tar.xz | tar xJC ${DEPS}/gm --strip-components=1
-cd ${DEPS}/gm
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --without-magick-plus-plus && make install-strip
-
-mkdir ${DEPS}/jpeg
-curl -Ls http://heanet.dl.sourceforge.net/project/libjpeg-turbo/${VERSION_JPEG}/libjpeg-turbo-${VERSION_JPEG}.tar.gz | tar xzC ${DEPS}/jpeg --strip-components=1
-cd ${DEPS}/jpeg
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --with-jpeg8 --without-turbojpeg && make install-strip
-
-mkdir ${DEPS}/png16
-curl -Ls http://heanet.dl.sourceforge.net/project/libpng/libpng16/${VERSION_PNG16}/libpng-${VERSION_PNG16}.tar.xz | tar xJC ${DEPS}/png16 --strip-components=1
-cd ${DEPS}/png16
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-mkdir ${DEPS}/webp
-curl -Ls http://downloads.webmproject.org/releases/webp/libwebp-${VERSION_WEBP}.tar.gz | tar xzC ${DEPS}/webp --strip-components=1
-cd ${DEPS}/webp
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-mkdir ${DEPS}/tiff
-curl -Ls http://download.osgeo.org/libtiff/tiff-${VERSION_TIFF}.tar.gz | tar xzC ${DEPS}/tiff --strip-components=1
-cd ${DEPS}/tiff
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-rm ${TARGET}/lib/libtiffxx*
-
-mkdir ${DEPS}/orc
-curl -Ls http://gstreamer.freedesktop.org/data/src/orc/orc-${VERSION_ORC}.tar.xz | tar xJC ${DEPS}/orc --strip-components=1
-cd ${DEPS}/orc
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-mkdir ${DEPS}/vips
-curl -Ls http://www.vips.ecs.soton.ac.uk/supported/8.2/vips-${VERSION_VIPS}.tar.gz | tar xzC ${DEPS}/vips --strip-components=1
-cd ${DEPS}/vips
-./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --disable-debug --disable-introspection --without-python --without-fftw --with-magickpackage=GraphicsMagick \
-  --with-zip-includes=${TARGET}/include --with-zip-libraries=${TARGET}/lib \
-  --with-jpeg-includes=${TARGET}/include --with-jpeg-libraries=${TARGET}/lib \
-  && make install-strip
-
-# Remove the old C++ bindings
-cd ${TARGET}/include
-rm -rf vips/vipsc++.h vips/vipscpp.h
-cd ${TARGET}/lib
-rm -rf pkgconfig .libs *.la libvipsCC*
-
-# Create JSON file of version numbers
-cd ${TARGET}
-echo "{\n\
-  \"exif\": \"${VERSION_EXIF}\",\n\
-  \"ffi\": \"${VERSION_FFI}\",\n\
-  \"glib\": \"${VERSION_GLIB}\",\n\
-  \"gsf\": \"${VERSION_GSF}\",\n\
-  \"jpeg\": \"${VERSION_JPEG}\",\n\
-  \"lcms\": \"${VERSION_LCMS2}\",\n\
-  \"gm\": \"${VERSION_GM}\",\n\
-  \"orc\": \"${VERSION_ORC}\",\n\
-  \"png\": \"${VERSION_PNG16}\",\n\
-  \"tiff\": \"${VERSION_TIFF}\",\n\
-  \"vips\": \"${VERSION_VIPS}\"\n\
-  \"webp\": \"${VERSION_WEBP}\",\n\
-  \"xml\": \"${VERSION_XML2}\",\n\
-  \"zlib\": \"${VERSION_ZLIB}\",\n\
-}" >lib/versions.json
-
-# Create .tar.gz
-GZIP=-9 tar czf /arm/libvips-${VERSION_VIPS}-arm.tar.gz include lib

packaging/build.sh

@@ -1,30 +0,0 @@
-#!/bin/sh
-
-VERSION_VIPS=8.2.3
-
-# Is docker available?
-
-if ! type docker >/dev/null; then
-  echo "Please install docker"
-  exit 1
-fi
-
-# TODO: docker v1.9.0 will allow build-time args - https://github.com/docker/docker/pull/15182
-
-# Windows
-
-docker build -t vips-dev-win win
-WIN_CONTAINER_ID=$(docker run -d vips-dev-win)
-docker cp "${WIN_CONTAINER_ID}:/libvips-${VERSION_VIPS}-win.tar.gz" .
-docker rm "${WIN_CONTAINER_ID}"
-
-# Linux
-
-docker build -t vips-dev-lin lin
-LIN_CONTAINER_ID=$(docker run -d vips-dev-lin)
-docker cp "${LIN_CONTAINER_ID}:/libvips-${VERSION_VIPS}-lin.tar.gz" .
-docker rm "${LIN_CONTAINER_ID}"
-
-# Checksums
-
-sha256sum *.tar.gz

packaging/lin/Dockerfile

@@ -1,139 +0,0 @@
-FROM debian:wheezy
-MAINTAINER Lovell Fuller <npm@lovell.info>
-
-# Build dependencies
-RUN apt-get update && apt-get install -y build-essential autoconf libtool nasm gtk-doc-tools texinfo
-
-# Create working directories
-ENV DEPS=/deps \
-    TARGET=/target
-RUN mkdir ${DEPS} && mkdir ${TARGET}
-
-# Common build paths and flags
-ENV PKG_CONFIG_PATH=${PKG_CONFIG_PATH}:${TARGET}/lib/pkgconfig \
-    PATH=${PATH}:${TARGET}/bin \
-    CPPFLAGS=-I${TARGET}/include \
-    LDFLAGS=-L${TARGET}/lib \
-    CFLAGS="-O3" \
-    CXXFLAGS="-O3"
-
-# Dependency version numbers
-ENV VERSION_ZLIB=1.2.8 \
-    VERSION_FFI=3.2.1 \
-    VERSION_GLIB=2.47.6 \
-    VERSION_XML2=2.9.3 \
-    VERSION_GSF=1.14.34 \
-    VERSION_EXIF=0.6.21 \
-    VERSION_LCMS2=2.7 \
-    VERSION_GM=1.3.23 \
-    VERSION_JPEG=1.4.2 \
-    VERSION_PNG16=1.6.21 \
-    VERSION_WEBP=0.5.0 \
-    VERSION_TIFF=4.0.6 \
-    VERSION_ORC=0.4.25 \
-    VERSION_VIPS=8.2.3
-
-RUN mkdir ${DEPS}/zlib
-RUN curl -Ls http://zlib.net/zlib-${VERSION_ZLIB}.tar.xz | tar xJC ${DEPS}/zlib --strip-components=1
-WORKDIR ${DEPS}/zlib
-RUN ./configure --prefix=${TARGET} && make install
-RUN rm ${TARGET}/lib/libz.a
-
-RUN mkdir ${DEPS}/ffi
-RUN curl -Ls ftp://sourceware.org/pub/libffi/libffi-${VERSION_FFI}.tar.gz | tar xzC ${DEPS}/ffi --strip-components=1
-WORKDIR ${DEPS}/ffi
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-builddir && make install-strip
-
-RUN mkdir ${DEPS}/glib
-RUN curl -Ls https://download.gnome.org/sources/glib/2.47/glib-${VERSION_GLIB}.tar.xz | tar xJC ${DEPS}/glib --strip-components=1
-WORKDIR ${DEPS}/glib
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --with-pcre=internal && make install-strip
-
-RUN mkdir ${DEPS}/xml2
-RUN curl -Ls http://xmlsoft.org/sources/libxml2-${VERSION_XML2}.tar.gz | tar xzC ${DEPS}/xml2 --strip-components=1
-WORKDIR ${DEPS}/xml2
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --without-python --with-zlib=${TARGET} && make install-strip
-
-RUN mkdir ${DEPS}/gsf
-RUN curl -Ls https://download.gnome.org/sources/libgsf/1.14/libgsf-${VERSION_GSF}.tar.xz | tar xJC ${DEPS}/gsf --strip-components=1
-WORKDIR ${DEPS}/gsf
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-RUN mkdir ${DEPS}/exif
-RUN curl -Ls http://heanet.dl.sourceforge.net/project/libexif/libexif/${VERSION_EXIF}/libexif-${VERSION_EXIF}.tar.bz2 | tar xjC ${DEPS}/exif --strip-components=1
-WORKDIR ${DEPS}/exif
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-RUN mkdir ${DEPS}/lcms2
-RUN curl -Ls http://heanet.dl.sourceforge.net/project/lcms/lcms/${VERSION_LCMS2}/lcms2-${VERSION_LCMS2}.tar.gz | tar xzC ${DEPS}/lcms2 --strip-components=1
-WORKDIR ${DEPS}/lcms2
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-RUN mkdir ${DEPS}/gm
-RUN curl -Ls http://heanet.dl.sourceforge.net/project/graphicsmagick/graphicsmagick/${VERSION_GM}/GraphicsMagick-${VERSION_GM}.tar.xz | tar xJC ${DEPS}/gm --strip-components=1
-WORKDIR ${DEPS}/gm
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --without-magick-plus-plus && make install-strip
-
-RUN mkdir ${DEPS}/jpeg
-RUN curl -Ls http://heanet.dl.sourceforge.net/project/libjpeg-turbo/${VERSION_JPEG}/libjpeg-turbo-${VERSION_JPEG}.tar.gz | tar xzC ${DEPS}/jpeg --strip-components=1
-WORKDIR ${DEPS}/jpeg
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --with-jpeg8 --without-turbojpeg && make install-strip
-
-RUN mkdir ${DEPS}/png16
-RUN curl -Ls http://heanet.dl.sourceforge.net/project/libpng/libpng16/${VERSION_PNG16}/libpng-${VERSION_PNG16}.tar.xz | tar xJC ${DEPS}/png16 --strip-components=1
-WORKDIR ${DEPS}/png16
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-RUN mkdir ${DEPS}/webp
-RUN curl -Ls http://downloads.webmproject.org/releases/webp/libwebp-${VERSION_WEBP}.tar.gz | tar xzC ${DEPS}/webp --strip-components=1
-WORKDIR ${DEPS}/webp
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-RUN mkdir ${DEPS}/tiff
-RUN curl -Ls http://download.osgeo.org/libtiff/tiff-${VERSION_TIFF}.tar.gz | tar xzC ${DEPS}/tiff --strip-components=1
-WORKDIR ${DEPS}/tiff
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-RUN rm ${TARGET}/lib/libtiffxx*
-
-RUN mkdir ${DEPS}/orc
-RUN curl -Ls http://gstreamer.freedesktop.org/data/src/orc/orc-${VERSION_ORC}.tar.xz | tar xJC ${DEPS}/orc --strip-components=1
-WORKDIR ${DEPS}/orc
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking && make install-strip
-
-RUN mkdir ${DEPS}/vips
-RUN curl -Ls http://www.vips.ecs.soton.ac.uk/supported/8.2/vips-${VERSION_VIPS}.tar.gz | tar xzC ${DEPS}/vips --strip-components=1
-WORKDIR ${DEPS}/vips
-RUN ./configure --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --disable-debug --disable-introspection --without-python --without-fftw --with-magickpackage=GraphicsMagick \
-  --with-zip-includes=${TARGET}/include --with-zip-libraries=${TARGET}/lib \
-  --with-jpeg-includes=${TARGET}/include --with-jpeg-libraries=${TARGET}/lib \
-  && make install-strip
-
-# Remove the old C++ bindings
-WORKDIR ${TARGET}/include
-RUN rm -rf vips/vipsc++.h vips/vipscpp.h
-WORKDIR ${TARGET}/lib
-RUN rm -rf pkgconfig .libs *.la libvipsCC*
-
-# Create JSON file of version numbers
-WORKDIR ${TARGET}
-RUN echo "{\n\
-  \"exif\": \"${VERSION_EXIF}\",\n\
-  \"ffi\": \"${VERSION_FFI}\",\n\
-  \"glib\": \"${VERSION_GLIB}\",\n\
-  \"gsf\": \"${VERSION_GSF}\",\n\
-  \"jpeg\": \"${VERSION_JPEG}\",\n\
-  \"lcms\": \"${VERSION_LCMS2}\",\n\
-  \"gm\": \"${VERSION_GM}\",\n\
-  \"orc\": \"${VERSION_ORC}\",\n\
-  \"png\": \"${VERSION_PNG16}\",\n\
-  \"tiff\": \"${VERSION_TIFF}\",\n\
-  \"vips\": \"${VERSION_VIPS}\"\n\
-  \"webp\": \"${VERSION_WEBP}\",\n\
-  \"xml\": \"${VERSION_XML2}\",\n\
-  \"zlib\": \"${VERSION_ZLIB}\",\n\
-}" >lib/versions.json
-
-# Create .tar.gz
-WORKDIR ${TARGET}
-RUN GZIP=-9 tar czf /libvips-${VERSION_VIPS}-lin.tar.gz include lib

packaging/test.sh

@@ -1,57 +0,0 @@
-#!/bin/sh
-
-# Verify docker is available
-if ! type docker >/dev/null; then
-  echo "Please install docker"
-  exit 1
-fi
-
-test="npm run clean; npm install --unsafe-perm; npm test"
-
-# Debian 7, 8
-# Ubuntu 12.04, 14.04
-for dist in wheezy jessie precise trusty; do
-  echo "Testing $dist..."
-  if docker run -i -t --rm -v $PWD:/v -e "NODE_ENV=development" nodesource/$dist:0.12 >packaging/$dist.log 2>&1 sh -c "cd /v; ./packaging/test/debian.sh; $test";
-  then echo "$dist OK"
-  else echo "$dist fail" && cat packaging/$dist.log
-  fi
-done
-
-# Centos 6
-echo "Testing centos6..."
-if docker run -i -t --rm -v $PWD:/v -e "NODE_ENV=development" nodesource/centos6:0.12 >packaging/centos6.log 2>&1 sh -c "cd /v; source ./packaging/test/centos6.sh; ./preinstall.sh; $test";
-then echo "centos6 OK"
-else echo "centos6 fail" && cat packaging/centos6.log
-fi
-
-# Centos 7
-# Fedora 20, 21
-for dist in centos7 fedora20 fedora21; do
-  echo "Testing $dist..."
-  if docker run -i -t --rm -v $PWD:/v -e "NODE_ENV=development" nodesource/$dist:0.12 >packaging/$dist.log 2>&1 sh -c "cd /v; $test";
-  then echo "$dist OK"
-  else echo "$dist fail" && cat packaging/$dist.log
-  fi
-done
-
-# openSUSE 13.2
-echo "Testing opensuse..."
-if docker run -i -t --rm -v $PWD:/v opensuse:13.2 >packaging/opensuse.log 2>&1 /bin/sh -c "cd /v; ./packaging/test/opensuse.sh; $test";
-then echo "opensuse OK"
-else echo "opensuse fail" && cat packaging/opensuse.log
-fi
-
-# Archlinux 2015.06.01
-echo "Testing archlinux..."
-if docker run -i -t --rm -v $PWD:/v base/archlinux:2015.06.01 >packaging/archlinux.log 2>&1 sh -c "cd /v; ./packaging/test/archlinux.sh; $test";
-then echo "archlinux OK"
-else echo "archlinux fail" && cat packaging/archlinux.log
-fi
-
-# Alpine
-echo "Testing alpine..."
-if docker run -i -t --rm -v $PWD:/v -e "SHARP_TEST_WITHOUT_CACHE=0" alpine:edge >packaging/alpine.log 2>&1 sh -c "cd /v; ./packaging/test/alpine.sh; $test";
-then echo "alpine OK"
-else echo "alpine fail" && cat packaging/alpine.log
-fi

packaging/test/alpine.sh

@@ -1,7 +0,0 @@
-#!/bin/sh
-
-# Install build dependencies
-apk add --update make gcc g++ python nodejs
-
-# Install libvips with build headers and dependencies
-apk add libvips-dev --update --repository https://s3.amazonaws.com/wjordan-apk --allow-untrusted

packaging/test/archlinux.sh

@@ -1,5 +0,0 @@
-#!/bin/sh
-
-# Install Node.js on Archlinux
-pacman -Sy --noconfirm gcc make python2 nodejs npm | cat
-ln -s /usr/bin/python2 /usr/bin/python

packaging/test/centos6.sh

@@ -1,8 +0,0 @@
-#!/bin/sh
-
-# Install C++11 compatible version of g++ on Centos 6
-curl -o /etc/yum.repos.d/devtools-1.1.repo http://people.centos.org/tru/devtools-1.1/devtools-1.1.repo
-yum install -y devtoolset-1.1
-export CC=/opt/centos/devtoolset-1.1/root/usr/bin/gcc
-export CPP=/opt/centos/devtoolset-1.1/root/usr/bin/cpp
-export CXX=/opt/centos/devtoolset-1.1/root/usr/bin/c++

packaging/test/debian.sh

@@ -1,5 +0,0 @@
-#!/bin/sh
-
-# Install pkg-config on Debian/Ubuntu
-apt-get update
-apt-get install -y pkg-config

packaging/test/opensuse.sh

@@ -1,7 +0,0 @@
-#!/bin/sh
-
-# Install Node.js on openSUSE 13.2
-zypper addrepo http://download.opensuse.org/repositories/devel:languages:nodejs/openSUSE_13.2/devel:languages:nodejs.repo
-zypper --gpg-auto-import-keys refresh
-zypper --non-interactive install gcc-c++ make nodejs-devel npm
-npm install -g npm

packaging/win/Dockerfile

@@ -1,20 +0,0 @@
-FROM ubuntu:precise
-MAINTAINER Lovell Fuller <npm@lovell.info>
-
-RUN apt-get update && apt-get install -y curl zip
-
-ENV VERSION_VIPS=8.2.3
-
-# Fetch and unzip
-RUN mkdir /vips
-WORKDIR /vips
-RUN curl -O http://www.vips.ecs.soton.ac.uk/supported/8.2/win32/vips-dev-w64-8.2.zip
-RUN unzip vips-dev-w64-8.2.zip
-
-# Clean and zip
-WORKDIR /vips/vips-dev-8.2
-RUN rm bin/libvipsCC-42.dll bin/libvips-cpp-42.dll bin/libgsf-win32-1-114.dll bin/libstdc++-6.dll
-RUN cp bin/*.dll lib/
-RUN cp -r lib64/* lib/
-
-RUN GZIP=-9 tar czf /libvips-${VERSION_VIPS}-win.tar.gz include lib/glib-2.0 lib/libvips.lib lib/libglib-2.0.lib lib/libgobject-2.0.lib lib/*.dll

preinstall.sh

@@ -1,322 +0,0 @@
-#!/bin/sh
-
-# This script is no longer required on most
-# 64-bit Linux systems when using sharp v0.12.0+
-
-# See http://sharp.dimens.io/page/install#linux
-
-# If you really need this script, it will attempt to
-# globally install libvips if not already available.
-
-# Supports:
-# * Debian Linux
-#   * Debian 7, 8
-#   * Ubuntu 12.04, 14.04, 14.10, 15.04, 15.10
-#   * Mint 13, 17
-#   * Elementary 0.3
-# * Red Hat Linux
-#   * RHEL/Centos/Scientific 6, 7
-#   * Fedora 21, 22, 23
-#   * Amazon Linux 2015.03, 2015.09
-# * OpenSuse 13
-
-vips_version_minimum=8.2.3
-vips_version_latest_major_minor=8.2
-vips_version_latest_patch=3
-
-openslide_version_minimum=3.4.0
-openslide_version_latest_major_minor=3.4
-openslide_version_latest_patch=1
-
-install_libvips_from_source() {
-  echo "Compiling libvips $vips_version_latest_major_minor.$vips_version_latest_patch from source"
-  curl -O http://www.vips.ecs.soton.ac.uk/supported/$vips_version_latest_major_minor/vips-$vips_version_latest_major_minor.$vips_version_latest_patch.tar.gz
-  tar zvxf vips-$vips_version_latest_major_minor.$vips_version_latest_patch.tar.gz
-  cd vips-$vips_version_latest_major_minor.$vips_version_latest_patch
-  ./configure --disable-debug --disable-docs --disable-static --disable-introspection --disable-dependency-tracking --enable-cxx=yes --without-python --without-orc --without-fftw $1
-  make
-  make install
-  cd ..
-  rm -rf vips-$vips_version_latest_major_minor.$vips_version_latest_patch
-  rm vips-$vips_version_latest_major_minor.$vips_version_latest_patch.tar.gz
-  ldconfig
-  echo "Installed libvips $(PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig:/usr/lib/pkgconfig pkg-config --modversion vips)"
-}
-
-install_libopenslide_from_source() {
-  echo "Compiling openslide $openslide_version_latest_major_minor.$openslide_version_latest_patch from source"
-  curl -O -L https://github.com/openslide/openslide/releases/download/v$openslide_version_latest_major_minor.$openslide_version_latest_patch/openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch.tar.gz
-  tar xzvf openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch.tar.gz
-  cd openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch
-  PKG_CONFIG_PATH=$pkg_config_path ./configure $1
-  make
-  make install
-  cd ..
-  rm -rf openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch
-  rm openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch.tar.gz
-  ldconfig
-  echo "Installed libopenslide $openslide_version_latest_major_minor.$openslide_version_latest_patch"
-}
-
-sorry() {
-  echo "Sorry, I don't yet know how to install lib$1 on $2"
-  exit 1
-}
-
-pkg_config_path="$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig:/usr/lib/pkgconfig"
-
-check_if_library_exists() {
-  PKG_CONFIG_PATH=$pkg_config_path pkg-config --exists $1
-  if [ $? -eq 0 ]; then
-    version_found=$(PKG_CONFIG_PATH=$pkg_config_path pkg-config --modversion $1)
-    PKG_CONFIG_PATH=$pkg_config_path pkg-config --atleast-version=$2 $1
-    if [ $? -eq 0 ]; then
-      # Found suitable version of libvips
-      echo "Found lib$1 $version_found"
-      return 1
-    fi
-    echo "Found lib$1 $version_found but require $2"
-  else
-    echo "Could not find lib$1 using a PKG_CONFIG_PATH of '$pkg_config_path'"
-  fi
-  return 0
-}
-
-enable_openslide=0
-# Is libvips already installed, and is it at least the minimum required version?
-if [ $# -eq 1 ]; then
-  if [ "$1" = "--with-openslide" ]; then
-    echo "Installing vips with openslide support"
-    enable_openslide=1
-  else
-    echo "Sorry, $1 is not supported. Did you mean --with-openslide?"
-    exit 1
-  fi
-fi
-
-if ! type pkg-config >/dev/null; then
-  sorry "vips" "a system without pkg-config"
-fi
-
-openslide_exists=0
-if [ $enable_openslide -eq 1 ]; then
-  check_if_library_exists "openslide" "$openslide_version_minimum"
-  openslide_exists=$?
-fi
-
-check_if_library_exists "vips" "$vips_version_minimum"
-vips_exists=$?
-if [ $vips_exists -eq 1 ] && [ $enable_openslide -eq 1 ]; then
-  if [ $openslide_exists -eq 1 ]; then
-    # Check if vips compiled with openslide support
-    vips_with_openslide=`vips list classes | grep -i opensli`
-    if [ -z $vips_with_openslide ]; then
-      echo "Vips compiled without openslide support."
-    else
-      exit 0
-    fi
-  fi
-elif [ $vips_exists -eq 1 ] && [ $enable_openslide -eq 0 ]; then
-  exit 0
-fi
-
-# Verify root/sudo access
-if [ "$(id -u)" -ne "0" ]; then
-  echo "Sorry, I need root/sudo access to continue"
-  exit 1
-fi
-
-# Deprecation warning
-if [ "$(arch)" == "x86_64" ]; then
-  echo "This script is no longer required on most 64-bit Linux systems when using sharp v0.12.0+"
-fi
-
-# OS-specific installations of libopenslide follows
-# Either openslide does not exist, or vips is installed without openslide support
-if [ $enable_openslide -eq 1 ] && [ -z $vips_with_openslide ] && [ $openslide_exists -eq 0 ]; then
-  if [ -f /etc/debian_version ]; then
-    # Debian Linux
-    DISTRO=$(lsb_release -c -s)
-    echo "Detected Debian Linux '$DISTRO'"
-    case "$DISTRO" in
-      jessie|vivid|wily)
-        # Debian 8, Ubuntu 15
-        echo "Installing libopenslide via apt-get"
-        apt-get install -y libopenslide-dev
-        ;;
-      trusty|utopic|qiana|rebecca|rafaela|freya)
-        # Ubuntu 14, Mint 17
-        echo "Installing libopenslide dependencies via apt-get"
-        apt-get install -y automake build-essential curl zlib1g-dev libopenjpeg-dev libpng12-dev libjpeg-dev libtiff5-dev libgdk-pixbuf2.0-dev libxml2-dev libsqlite3-dev libcairo2-dev libglib2.0-dev sqlite3 libsqlite3-dev
-        install_libopenslide_from_source
-        ;;
-      precise|wheezy|maya)
-        # Debian 7, Ubuntu 12.04, Mint 13
-        echo "Installing libopenslide dependencies via apt-get"
-        apt-get install -y automake build-essential curl zlib1g-dev libopenjpeg-dev libpng12-dev libjpeg-dev libtiff5-dev libgdk-pixbuf2.0-dev libxml2-dev libsqlite3-dev libcairo2-dev libglib2.0-dev sqlite3 libsqlite3-dev
-        install_libopenslide_from_source
-        ;;
-      *)
-        # Unsupported Debian-based OS
-        sorry "openslide" "Debian-based $DISTRO"
-        ;;
-    esac
-  elif [ -f /etc/redhat-release ]; then
-    # Red Hat Linux
-    RELEASE=$(cat /etc/redhat-release)
-    echo "Detected Red Hat Linux '$RELEASE'"
-    case $RELEASE in
-      "Red Hat Enterprise Linux release 7."*|"CentOS Linux release 7."*|"Scientific Linux release 7."*)
-        # RHEL/CentOS 7
-        echo "Installing libopenslide dependencies via yum"
-        yum groupinstall -y "Development Tools"
-        yum install -y tar curl libpng-devel libjpeg-devel libxml2-devel zlib-devel openjpeg-devel libtiff-devel gdk-pixbuf2-devel sqlite-devel cairo-devel glib2-devel
-        install_libopenslide_from_source "--prefix=/usr"
-        ;;
-      "Red Hat Enterprise Linux release 6."*|"CentOS release 6."*|"Scientific Linux release 6."*)
-        # RHEL/CentOS 6
-        echo "Installing libopenslide dependencies via yum"
-        yum groupinstall -y "Development Tools"
-        yum install -y tar curl libpng-devel libjpeg-devel libxml2-devel zlib-devel openjpeg-devel libtiff-devel gdk-pixbuf2-devel sqlite-devel cairo-devel glib2-devel
-        install_libopenslide_from_source "--prefix=/usr"
-        ;;
-      "Fedora release 21 "*|"Fedora release 22 "*)
-        # Fedora 21, 22
-        echo "Installing libopenslide via yum"
-        yum install -y openslide-devel
-        ;;
-      *)
-        # Unsupported RHEL-based OS
-        sorry "openslide" "$RELEASE"
-        ;;
-    esac
-  elif [ -f /etc/os-release ]; then
-    RELEASE=$(cat /etc/os-release | grep VERSION)
-    echo "Detected OpenSuse Linux '$RELEASE'"
-    case $RELEASE in
-      *"13.2"*)
-      echo "Installing libopenslide via zypper"
-      zypper --gpg-auto-import-keys install -y libopenslide-devel
-      ;;
-    esac
-  elif [ -f /etc/SuSE-brand ]; then
-    RELEASE=$(cat /etc/SuSE-brand | grep VERSION)
-    echo "Detected OpenSuse Linux '$RELEASE'"
-    case $RELEASE in
-      *"13.1")
-      echo "Installing libopenslide dependencies via zypper"
-      zypper --gpg-auto-import-keys install -y --type pattern devel_basis
-      zypper --gpg-auto-import-keys install -y tar curl libpng16-devel libjpeg-turbo libjpeg8-devel libxml2-devel zlib-devel openjpeg-devel libtiff-devel libgdk_pixbuf-2_0-0 sqlite3-devel cairo-devel glib2-devel
-      install_libopenslide_from_source
-      ;;
-    esac
-  else
-    # Unsupported OS
-    sorry "openslide" "$(uname -a)"
-  fi
-fi
-
-# OS-specific installations of libvips follows
-
-if [ -f /etc/debian_version ]; then
-  # Debian Linux
-  DISTRO=$(lsb_release -c -s)
-  echo "Detected Debian Linux '$DISTRO'"
-  case "$DISTRO" in
-    jessie|trusty|utopic|vivid|wily|xenial|qiana|rebecca|rafaela|freya)
-      # Debian 8, Ubuntu 14.04+, Mint 17
-      echo "Installing libvips dependencies via apt-get"
-      apt-get install -y automake build-essential gobject-introspection gtk-doc-tools libglib2.0-dev libjpeg-dev libpng12-dev libwebp-dev libtiff5-dev libexif-dev libgsf-1-dev liblcms2-dev libxml2-dev swig libmagickcore-dev curl
-      install_libvips_from_source
-      ;;
-    precise|wheezy|maya)
-      # Debian 7, Ubuntu 12.04, Mint 13
-      echo "Installing libvips dependencies via apt-get"
-      add-apt-repository -y ppa:lyrasis/precise-backports
-      apt-get update
-      apt-get install -y automake build-essential gobject-introspection gtk-doc-tools libglib2.0-dev libjpeg-dev libpng12-dev libwebp-dev libtiff4-dev libexif-dev libgsf-1-dev liblcms2-dev libxml2-dev swig libmagickcore-dev curl
-      install_libvips_from_source
-      ;;
-    *)
-      # Unsupported Debian-based OS
-      sorry "vips" "Debian-based $DISTRO"
-      ;;
-  esac
-elif [ -f /etc/redhat-release ]; then
-  # Red Hat Linux
-  RELEASE=$(cat /etc/redhat-release)
-  echo "Detected Red Hat Linux '$RELEASE'"
-  case $RELEASE in
-    "Red Hat Enterprise Linux release 7."*|"CentOS Linux release 7."*|"Scientific Linux release 7."*)
-      # RHEL/CentOS 7
-      echo "Installing libvips dependencies via yum"
-      yum groupinstall -y "Development Tools"
-      yum install -y tar curl gtk-doc libxml2-devel libjpeg-turbo-devel libpng-devel libtiff-devel libexif-devel libgsf-devel lcms2-devel ImageMagick-devel gobject-introspection-devel libwebp-devel
-      install_libvips_from_source "--prefix=/usr"
-      ;;
-    "Red Hat Enterprise Linux release 6."*|"CentOS release 6."*|"Scientific Linux release 6."*)
-      # RHEL/CentOS 6
-      echo "Installing libvips dependencies via yum"
-      yum groupinstall -y "Development Tools"
-      yum install -y tar curl gtk-doc libxml2-devel libjpeg-turbo-devel libpng-devel libtiff-devel libexif-devel libgsf-devel lcms-devel ImageMagick-devel
-      yum install -y http://li.nux.ro/download/nux/dextop/el6/x86_64/nux-dextop-release-0-2.el6.nux.noarch.rpm
-      yum install -y --enablerepo=nux-dextop gobject-introspection-devel
-      yum install -y http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
-      yum install -y --enablerepo=remi libwebp-devel
-      install_libvips_from_source "--prefix=/usr"
-      ;;
-    "Fedora"*)
-      # Fedora 21, 22, 23
-      echo "Installing libvips dependencies via yum"
-      yum groupinstall -y "Development Tools"
-      yum install -y gcc-c++ gtk-doc libxml2-devel libjpeg-turbo-devel libpng-devel libtiff-devel libexif-devel lcms-devel ImageMagick-devel gobject-introspection-devel libwebp-devel curl
-      install_libvips_from_source "--prefix=/usr"
-      ;;
-    *)
-      # Unsupported RHEL-based OS
-      sorry "vips" "$RELEASE"
-      ;;
-  esac
-elif [ -f /etc/system-release ]; then
-  # Probably Amazon Linux
-  RELEASE=$(cat /etc/system-release)
-  case $RELEASE in
-    "Amazon Linux AMI release 2015.03"|"Amazon Linux AMI release 2015.09")
-      # Amazon Linux
-      echo "Detected '$RELEASE'"
-      echo "Installing libvips dependencies via yum"
-      yum groupinstall -y "Development Tools"
-      yum install -y gtk-doc libxml2-devel libjpeg-turbo-devel libpng-devel libtiff-devel libexif-devel libgsf-devel lcms2-devel ImageMagick-devel gobject-introspection-devel libwebp-devel curl
-      install_libvips_from_source "--prefix=/usr"
-      ;;
-    *)
-      # Unsupported Amazon Linux version
-      sorry "vips" "$RELEASE"
-      ;;
-  esac
-elif [ -f /etc/os-release ]; then
-  RELEASE=$(cat /etc/os-release | grep VERSION)
-  echo "Detected OpenSuse Linux '$RELEASE'"
-  case $RELEASE in
-    *"13.2"*)
-    echo "Installing libvips dependencies via zypper"
-    zypper --gpg-auto-import-keys install -y --type pattern devel_basis
-    zypper --gpg-auto-import-keys install -y tar curl gtk-doc libxml2-devel libjpeg-turbo libjpeg8-devel libpng16-devel libtiff-devel libexif-devel liblcms2-devel ImageMagick-devel gobject-introspection-devel libwebp-devel
-    install_libvips_from_source
-    ;;
-  esac
-elif [ -f /etc/SuSE-brand ]; then
-  RELEASE=$(cat /etc/SuSE-brand | grep VERSION)
-  echo "Detected OpenSuse Linux '$RELEASE'"
-  case $RELEASE in
-    *"13.1")
-    echo "Installing libvips dependencies via zypper"
-    zypper --gpg-auto-import-keys install -y --type pattern devel_basis
-    zypper --gpg-auto-import-keys install -y tar curl gtk-doc libxml2-devel libjpeg-turbo libjpeg8-devel libpng16-devel libtiff-devel libexif-devel liblcms2-devel ImageMagick-devel gobject-introspection-devel libwebp-devel
-    install_libvips_from_source
-    ;;
-  esac
-else
-  # Unsupported OS
-  sorry "vips" "$(uname -a)"
-fi

src/common.cc

@@ -1,32 +1,90 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #include <cstdlib>
 #include <string>
 #include <string.h>
+#include <vector>
+#include <queue>
+#include <mutex>
+
+#include <node.h>
+#include <node_buffer.h>
+#include <nan.h>
 #include <vips/vips8>
 
 #include "common.h"
 
-// Verify platform and compiler compatibility
-
-#if (VIPS_MAJOR_VERSION < 8 || (VIPS_MAJOR_VERSION == 8 && VIPS_MINOR_VERSION < 2))
-#error libvips version 8.2.0+ required - see sharp.dimens.io/page/install
-#endif
-
-#if ((!defined(__clang__)) && defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)))
-#error GCC version 4.6+ is required for C++11 features - see sharp.dimens.io/page/install#prerequisites
-#endif
-
-#if (defined(__clang__) && defined(__has_feature))
-#if (!__has_feature(cxx_range_for))
-#error clang version 3.0+ is required for C++11 features - see sharp.dimens.io/page/install#prerequisites
-#endif
-#endif
-
-#define EXIF_IFD0_ORIENTATION "exif-ifd0-Orientation"
-
 using vips::VImage;
 
 namespace sharp {
 
+  // Convenience methods to access the attributes of a v8::Object
+  bool HasAttr(v8::Handle<v8::Object> obj, std::string attr) {
+    return Nan::Has(obj, Nan::New(attr).ToLocalChecked()).FromJust();
+  }
+  std::string AttrAsStr(v8::Handle<v8::Object> obj, std::string attr) {
+    return *Nan::Utf8String(Nan::Get(obj, Nan::New(attr).ToLocalChecked()).ToLocalChecked());
+  }
+  std::vector<double> AttrAsRgba(v8::Handle<v8::Object> obj, std::string attr) {
+    v8::Local<v8::Object> background = AttrAs<v8::Object>(obj, attr);
+    std::vector<double> rgba(4);
+    for (unsigned int i = 0; i < 4; i++) {
+      rgba[i] = AttrTo<double>(background, i);
+    }
+    return rgba;
+  }
+
+  // Create an InputDescriptor instance from a v8::Object describing an input image
+  InputDescriptor* CreateInputDescriptor(
+    v8::Handle<v8::Object> input, std::vector<v8::Local<v8::Object>> &buffersToPersist
+  ) {
+    Nan::HandleScope();
+    InputDescriptor *descriptor = new InputDescriptor;
+    if (HasAttr(input, "file")) {
+      descriptor->file = AttrAsStr(input, "file");
+    } else if (HasAttr(input, "buffer")) {
+      v8::Local<v8::Object> buffer = AttrAs<v8::Object>(input, "buffer");
+      descriptor->bufferLength = node::Buffer::Length(buffer);
+      descriptor->buffer = node::Buffer::Data(buffer);
+      buffersToPersist.push_back(buffer);
+    }
+    descriptor->failOnError = AttrTo<bool>(input, "failOnError");
+    // Density for vector-based input
+    if (HasAttr(input, "density")) {
+      descriptor->density = AttrTo<double>(input, "density");
+    }
+    // Raw pixel input
+    if (HasAttr(input, "rawChannels")) {
+      descriptor->rawChannels = AttrTo<uint32_t>(input, "rawChannels");
+      descriptor->rawWidth = AttrTo<uint32_t>(input, "rawWidth");
+      descriptor->rawHeight = AttrTo<uint32_t>(input, "rawHeight");
+    }
+    // Page input for multi-page TIFF
+    if (HasAttr(input, "page")) {
+      descriptor->page = AttrTo<uint32_t>(input, "page");
+    }
+    // Create new image
+    if (HasAttr(input, "createChannels")) {
+      descriptor->createChannels = AttrTo<uint32_t>(input, "createChannels");
+      descriptor->createWidth = AttrTo<uint32_t>(input, "createWidth");
+      descriptor->createHeight = AttrTo<uint32_t>(input, "createHeight");
+      descriptor->createBackground = AttrAsRgba(input, "createBackground");
+    }
+    return descriptor;
+  }
+
   // How many tasks are in the queue?
   volatile int counterQueue = 0;
 
@@ -55,6 +113,9 @@ namespace sharp {
   bool IsDzZip(std::string const &str) {
     return EndsWith(str, ".zip") || EndsWith(str, ".ZIP") || EndsWith(str, ".szi") || EndsWith(str, ".SZI");
   }
+  bool IsV(std::string const &str) {
+    return EndsWith(str, ".v") || EndsWith(str, ".V") || EndsWith(str, ".vips") || EndsWith(str, ".VIPS");
+  }
 
   /*
     Provide a string identifier for the given image type.
@@ -66,10 +127,14 @@ namespace sharp {
       case ImageType::PNG: id = "png"; break;
       case ImageType::WEBP: id = "webp"; break;
       case ImageType::TIFF: id = "tiff"; break;
+      case ImageType::GIF: id = "gif"; break;
+      case ImageType::SVG: id = "svg"; break;
+      case ImageType::PDF: id = "pdf"; break;
       case ImageType::MAGICK: id = "magick"; break;
       case ImageType::OPENSLIDE: id = "openslide"; break;
       case ImageType::PPM: id = "ppm"; break;
       case ImageType::FITS: id = "fits"; break;
+      case ImageType::VIPS: id = "v"; break;
       case ImageType::RAW: id = "raw"; break;
       case ImageType::UNKNOWN: id = "unknown"; break;
     }
@@ -92,6 +157,12 @@ namespace sharp {
         imageType = ImageType::WEBP;
       } else if (EndsWith(loader, "TiffBuffer")) {
         imageType = ImageType::TIFF;
+      } else if (EndsWith(loader, "GifBuffer")) {
+        imageType = ImageType::GIF;
+      } else if (EndsWith(loader, "SvgBuffer")) {
+        imageType = ImageType::SVG;
+      } else if (EndsWith(loader, "PdfBuffer")) {
+        imageType = ImageType::PDF;
       } else if (EndsWith(loader, "MagickBuffer")) {
         imageType = ImageType::MAGICK;
       }
@@ -117,10 +188,18 @@ namespace sharp {
         imageType = ImageType::OPENSLIDE;
       } else if (EndsWith(loader, "TiffFile")) {
         imageType = ImageType::TIFF;
+      } else if (EndsWith(loader, "GifFile")) {
+        imageType = ImageType::GIF;
+      } else if (EndsWith(loader, "SvgFile")) {
+        imageType = ImageType::SVG;
+      } else if (EndsWith(loader, "PdfFile")) {
+        imageType = ImageType::PDF;
       } else if (EndsWith(loader, "Ppm")) {
         imageType = ImageType::PPM;
       } else if (EndsWith(loader, "Fits")) {
         imageType = ImageType::FITS;
+      } else if (EndsWith(loader, "Vips")) {
+        imageType = ImageType::VIPS;
       } else if (EndsWith(loader, "Magick") || EndsWith(loader, "MagickFile")) {
         imageType = ImageType::MAGICK;
       }
@@ -128,6 +207,97 @@ namespace sharp {
     return imageType;
   }
 
+  /*
+    Open an image from the given InputDescriptor (filesystem, compressed buffer, raw pixel data)
+  */
+  std::tuple<VImage, ImageType> OpenInput(InputDescriptor *descriptor, VipsAccess accessMethod) {
+    VImage image;
+    ImageType imageType;
+    if (descriptor->buffer != nullptr) {
+      if (descriptor->rawChannels > 0) {
+        // Raw, uncompressed pixel data
+        image = VImage::new_from_memory(descriptor->buffer, descriptor->bufferLength,
+          descriptor->rawWidth, descriptor->rawHeight, descriptor->rawChannels, VIPS_FORMAT_UCHAR);
+        if (descriptor->rawChannels < 3) {
+          image.get_image()->Type = VIPS_INTERPRETATION_B_W;
+        } else {
+          image.get_image()->Type = VIPS_INTERPRETATION_sRGB;
+        }
+        imageType = ImageType::RAW;
+      } else {
+        // Compressed data
+        imageType = DetermineImageType(descriptor->buffer, descriptor->bufferLength);
+        if (imageType != ImageType::UNKNOWN) {
+          try {
+            vips::VOption *option = VImage::option()
+              ->set("access", accessMethod)
+              ->set("fail", descriptor->failOnError);
+            if (imageType == ImageType::SVG || imageType == ImageType::PDF) {
+              option->set("dpi", descriptor->density);
+            }
+            if (imageType == ImageType::MAGICK) {
+              option->set("density", std::to_string(descriptor->density).data());
+            }
+            if (imageType == ImageType::TIFF) {
+             option->set("page", descriptor->page);
+            }
+            image = VImage::new_from_buffer(descriptor->buffer, descriptor->bufferLength, nullptr, option);
+            if (imageType == ImageType::SVG || imageType == ImageType::PDF || imageType == ImageType::MAGICK) {
+              SetDensity(image, descriptor->density);
+            }
+          } catch (vips::VError const &err) {
+            throw vips::VError(std::string("Input buffer has corrupt header: ") + err.what());
+          }
+        } else {
+          throw vips::VError("Input buffer contains unsupported image format");
+        }
+      }
+    } else {
+      if (descriptor->createChannels > 0) {
+        // Create new image
+        std::vector<double> background = {
+          descriptor->createBackground[0],
+          descriptor->createBackground[1],
+          descriptor->createBackground[2]
+        };
+        if (descriptor->createChannels == 4) {
+          background.push_back(descriptor->createBackground[3]);
+        }
+        image = VImage::new_matrix(descriptor->createWidth, descriptor->createHeight).new_from_image(background);
+        image.get_image()->Type = VIPS_INTERPRETATION_sRGB;
+        imageType = ImageType::RAW;
+      } else {
+        // From filesystem
+        imageType = DetermineImageType(descriptor->file.data());
+        if (imageType != ImageType::UNKNOWN) {
+          try {
+            vips::VOption *option = VImage::option()
+              ->set("access", accessMethod)
+              ->set("fail", descriptor->failOnError);
+            if (imageType == ImageType::SVG || imageType == ImageType::PDF) {
+              option->set("dpi", descriptor->density);
+            }
+            if (imageType == ImageType::MAGICK) {
+              option->set("density", std::to_string(descriptor->density).data());
+            }
+            if (imageType == ImageType::TIFF) {
+             option->set("page", descriptor->page);
+            }
+            image = VImage::new_from_file(descriptor->file.data(), option);
+            if (imageType == ImageType::SVG || imageType == ImageType::PDF || imageType == ImageType::MAGICK) {
+              SetDensity(image, descriptor->density);
+            }
+          } catch (vips::VError const &err) {
+            throw vips::VError(std::string("Input file has corrupt header: ") + err.what());
+          }
+        } else {
+          throw vips::VError("Input file is missing or of an unsupported image format");
+        }
+      }
+    }
+    return std::make_tuple(image, imageType);
+  }
+
   /*
     Does this image have an embedded profile?
   */
@@ -145,8 +315,7 @@ namespace sharp {
     return (
       (bands == 2 && interpretation == VIPS_INTERPRETATION_B_W) ||
       (bands == 4 && interpretation != VIPS_INTERPRETATION_CMYK) ||
-      (bands == 5 && interpretation == VIPS_INTERPRETATION_CMYK)
+      (bands == 5 && interpretation == VIPS_INTERPRETATION_CMYK));
-    );
   }
 
   /*
@@ -154,11 +323,8 @@ namespace sharp {
   */
   int ExifOrientation(VImage image) {
     int orientation = 0;
-    if (image.get_typeof(EXIF_IFD0_ORIENTATION) != 0) {
+    if (image.get_typeof(VIPS_META_ORIENTATION) != 0) {
-      char const *exif = image.get_string(EXIF_IFD0_ORIENTATION);
+      orientation = image.get_int(VIPS_META_ORIENTATION);
-      if (exif != nullptr) {
-        orientation = atoi(&exif[0]);
-      }
     }
     return orientation;
   }
@@ -167,16 +333,14 @@ namespace sharp {
     Set EXIF Orientation of image.
   */
   void SetExifOrientation(VImage image, int const orientation) {
-    char exif[3];
+    image.set(VIPS_META_ORIENTATION, orientation);
-    g_snprintf(exif, sizeof(exif), "%d", orientation);
-    image.set(EXIF_IFD0_ORIENTATION, exif);
   }
 
   /*
     Remove EXIF Orientation from image.
   */
   void RemoveExifOrientation(VImage image) {
-    SetExifOrientation(image, 0);
+    vips_image_remove(image.get_image(), VIPS_META_ORIENTATION);
   }
 
   /*
@@ -196,13 +360,28 @@ namespace sharp {
   /*
     Set pixels/mm resolution based on a pixels/inch density.
   */
-  void SetDensity(VImage image, const int density) {
+  void SetDensity(VImage image, const double density) {
-    const double pixelsPerMm = static_cast<double>(density) / 25.4;
+    const double pixelsPerMm = density / 25.4;
     image.set("Xres", pixelsPerMm);
     image.set("Yres", pixelsPerMm);
     image.set(VIPS_META_RESOLUTION_UNIT, "in");
   }
 
+  /*
+    Check the proposed format supports the current dimensions.
+  */
+  void AssertImageTypeDimensions(VImage image, ImageType const imageType) {
+    if (imageType == ImageType::JPEG) {
+      if (image.width() > 65535 || image.height() > 65535) {
+        throw vips::VError("Processed image is too large for the JPEG format");
+      }
+    } else if (imageType == ImageType::WEBP) {
+      if (image.width() > 16383 || image.height() > 16383) {
+        throw vips::VError("Processed image is too large for the WebP format");
+      }
+    }
+  }
+
   /*
     Called when a Buffer undergoes GC, required to support mixed runtime libraries in Windows
   */
@@ -212,9 +391,91 @@ namespace sharp {
     }
   }
 
+  /*
+    Temporary buffer of warnings
+  */
+  std::queue<std::string> vipsWarnings;
+  std::mutex vipsWarningsMutex;
+
+  /*
+    Called with warnings from the glib-registered "VIPS" domain
+  */
+  void VipsWarningCallback(char const* log_domain, GLogLevelFlags log_level, char const* message, void* ignore) {
+    std::lock_guard<std::mutex> lock(vipsWarningsMutex);
+    vipsWarnings.emplace(message);
+  }
+
+  /*
+    Pop the oldest warning message from the queue
+  */
+  std::string VipsWarningPop() {
+    std::string warning;
+    std::lock_guard<std::mutex> lock(vipsWarningsMutex);
+    if (!vipsWarnings.empty()) {
+      warning = vipsWarnings.front();
+      vipsWarnings.pop();
+    }
+    return warning;
+  }
+
   /*
     Calculate the (left, top) coordinates of the output image
-    within the input image, applying the given gravity.
+    within the input image, applying the given gravity during an embed.
+
+    @Azurebyte: We are basically swapping the inWidth and outWidth, inHeight and outHeight from the CalculateCrop function.
+  */
+  std::tuple<int, int> CalculateEmbedPosition(int const inWidth, int const inHeight,
+    int const outWidth, int const outHeight, int const gravity) {
+
+    int left = 0;
+    int top = 0;
+    switch (gravity) {
+      case 1:
+        // North
+        left = (outWidth - inWidth) / 2;
+        break;
+      case 2:
+        // East
+        left = outWidth - inWidth;
+        top = (outHeight - inHeight) / 2;
+        break;
+      case 3:
+        // South
+        left = (outWidth - inWidth) / 2;
+        top = outHeight - inHeight;
+        break;
+      case 4:
+        // West
+        top = (outHeight - inHeight) / 2;
+        break;
+      case 5:
+        // Northeast
+        left = outWidth - inWidth;
+        break;
+      case 6:
+        // Southeast
+        left = outWidth - inWidth;
+        top = outHeight - inHeight;
+        break;
+      case 7:
+        // Southwest
+        top = outHeight - inHeight;
+        break;
+      case 8:
+        // Northwest
+        // Which is the default is 0,0 so we do not assign anything here.
+        break;
+      default:
+        // Centre
+        left = (outWidth - inWidth) / 2;
+        top = (outHeight - inHeight) / 2;
+    }
+    return std::make_tuple(left, top);
+  }
+
+  /*
+    Calculate the (left, top) coordinates of the output image
+    within the input image, applying the given gravity during a crop.
   */
   std::tuple<int, int> CalculateCrop(int const inWidth, int const inHeight,
     int const outWidth, int const outHeight, int const gravity) {
@@ -248,9 +509,11 @@ namespace sharp {
         // Southeast
         left = inWidth - outWidth;
         top = inHeight - outHeight;
+        break;
       case 7:
         // Southwest
         top = inHeight - outHeight;
+        break;
       case 8:
         // Northwest
         break;
@@ -262,4 +525,122 @@ namespace sharp {
     return std::make_tuple(left, top);
   }
 
+  /*
+    Calculate the (left, top) coordinates of the output image
+    within the input image, applying the given x and y offsets.
+  */
+  std::tuple<int, int> CalculateCrop(int const inWidth, int const inHeight,
+    int const outWidth, int const outHeight, int const x, int const y) {
+
+    // default values
+    int left = 0;
+    int top = 0;
+
+    // assign only if valid
+    if (x >= 0 && x < (inWidth - outWidth)) {
+      left = x;
+    } else if (x >= (inWidth - outWidth)) {
+      left = inWidth - outWidth;
+    }
+
+    if (y >= 0 && y < (inHeight - outHeight)) {
+      top = y;
+    } else if (y >= (inHeight - outHeight)) {
+      top = inHeight - outHeight;
+    }
+
+    // the resulting left and top could have been outside the image after calculation from bottom/right edges
+    if (left < 0) {
+      left = 0;
+    }
+    if (top < 0) {
+      top = 0;
+    }
+
+    return std::make_tuple(left, top);
+  }
+
+  /*
+    Are pixel values in this image 16-bit integer?
+  */
+  bool Is16Bit(VipsInterpretation const interpretation) {
+    return interpretation == VIPS_INTERPRETATION_RGB16 || interpretation == VIPS_INTERPRETATION_GREY16;
+  }
+
+  /*
+    Return the image alpha maximum. Useful for combining alpha bands. scRGB
+    images are 0 - 1 for image data, but the alpha is 0 - 255.
+  */
+  double MaximumImageAlpha(VipsInterpretation const interpretation) {
+    return Is16Bit(interpretation) ? 65535.0 : 255.0;
+  }
+
+  /*
+    Get boolean operation type from string
+  */
+  VipsOperationBoolean GetBooleanOperation(std::string const opStr) {
+    return static_cast<VipsOperationBoolean>(
+      vips_enum_from_nick(nullptr, VIPS_TYPE_OPERATION_BOOLEAN, opStr.data()));
+  }
+
+  /*
+    Get interpretation type from string
+  */
+  VipsInterpretation GetInterpretation(std::string const typeStr) {
+    return static_cast<VipsInterpretation>(
+      vips_enum_from_nick(nullptr, VIPS_TYPE_INTERPRETATION, typeStr.data()));
+  }
+
+  /*
+    Convert RGBA value to another colourspace
+  */
+  std::vector<double> GetRgbaAsColourspace(std::vector<double> const rgba, VipsInterpretation const interpretation) {
+    int const bands = static_cast<int>(rgba.size());
+    if (bands < 3 || interpretation == VIPS_INTERPRETATION_sRGB || interpretation == VIPS_INTERPRETATION_RGB) {
+      return rgba;
+    } else {
+      VImage pixel = VImage::new_matrix(1, 1);
+      pixel.set("bands", bands);
+      pixel = pixel.new_from_image(rgba);
+      pixel = pixel.colourspace(interpretation, VImage::option()->set("source_space", VIPS_INTERPRETATION_sRGB));
+      return pixel(0, 0);
+    }
+  }
+
+  /*
+    Apply the alpha channel to a given colour
+  */
+  std::tuple<VImage, std::vector<double>> ApplyAlpha(VImage image, std::vector<double> colour) {
+    // Scale up 8-bit values to match 16-bit input image
+    double const multiplier = sharp::Is16Bit(image.interpretation()) ? 256.0 : 1.0;
+    // Create alphaColour colour
+    std::vector<double> alphaColour;
+    if (image.bands() > 2) {
+      alphaColour = {
+        multiplier * colour[0],
+        multiplier * colour[1],
+        multiplier * colour[2]
+      };
+    } else {
+      // Convert sRGB to greyscale
+      alphaColour = { multiplier * (
+        0.2126 * colour[0] +
+        0.7152 * colour[1] +
+        0.0722 * colour[2])
+      };
+    }
+    // Add alpha channel to alphaColour colour
+    if (colour[3] < 255.0 || HasAlpha(image)) {
+      alphaColour.push_back(colour[3] * multiplier);
+    }
+    // Ensure alphaColour colour uses correct colourspace
+    alphaColour = sharp::GetRgbaAsColourspace(alphaColour, image.interpretation());
+    // Add non-transparent alpha channel, if required
+    if (colour[3] < 255.0 && !HasAlpha(image)) {
+      image = image.bandjoin(
+        VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier));
+    }
+    return std::make_tuple(image, alphaColour);
+  }
+
 }  // namespace sharp

src/common.h

@@ -1,26 +1,112 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #ifndef SRC_COMMON_H_
 #define SRC_COMMON_H_
 
 #include <string>
 #include <tuple>
+#include <vector>
 
+#include <node.h>
+#include <nan.h>
 #include <vips/vips8>
 
+// Verify platform and compiler compatibility
+
+#if (VIPS_MAJOR_VERSION < 8 || (VIPS_MAJOR_VERSION == 8 && VIPS_MINOR_VERSION < 7))
+#error libvips version 8.7.0+ is required - see sharp.pixelplumbing.com/page/install
+#endif
+
+#if ((!defined(__clang__)) && defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)))
+#error GCC version 4.6+ is required for C++11 features - see sharp.pixelplumbing.com/page/install#prerequisites
+#endif
+
+#if (defined(__clang__) && defined(__has_feature))
+#if (!__has_feature(cxx_range_for))
+#error clang version 3.0+ is required for C++11 features - see sharp.pixelplumbing.com/page/install#prerequisites
+#endif
+#endif
+
 using vips::VImage;
 
 namespace sharp {
 
+  struct InputDescriptor {
+    std::string name;
+    std::string file;
+    char *buffer;
+    bool failOnError;
+    size_t bufferLength;
+    double density;
+    int rawChannels;
+    int rawWidth;
+    int rawHeight;
+    int page;
+    int createChannels;
+    int createWidth;
+    int createHeight;
+    std::vector<double> createBackground;
+
+    InputDescriptor():
+      buffer(nullptr),
+      failOnError(FALSE),
+      bufferLength(0),
+      density(72.0),
+      rawChannels(0),
+      rawWidth(0),
+      rawHeight(0),
+      page(0),
+      createChannels(0),
+      createWidth(0),
+      createHeight(0),
+      createBackground{ 0.0, 0.0, 0.0, 255.0 } {}
+  };
+
+  // Convenience methods to access the attributes of a v8::Object
+  bool HasAttr(v8::Handle<v8::Object> obj, std::string attr);
+  std::string AttrAsStr(v8::Handle<v8::Object> obj, std::string attr);
+  std::vector<double> AttrAsRgba(v8::Handle<v8::Object> obj, std::string attr);
+  template<typename T> v8::Local<T> AttrAs(v8::Handle<v8::Object> obj, std::string attr) {
+    return Nan::Get(obj, Nan::New(attr).ToLocalChecked()).ToLocalChecked().As<T>();
+  }
+  template<typename T> T AttrTo(v8::Handle<v8::Object> obj, std::string attr) {
+    return Nan::To<T>(Nan::Get(obj, Nan::New(attr).ToLocalChecked()).ToLocalChecked()).FromJust();
+  }
+  template<typename T> T AttrTo(v8::Handle<v8::Object> obj, int attr) {
+    return Nan::To<T>(Nan::Get(obj, attr).ToLocalChecked()).FromJust();
+  }
+
+  // Create an InputDescriptor instance from a v8::Object describing an input image
+  InputDescriptor* CreateInputDescriptor(
+    v8::Handle<v8::Object> input, std::vector<v8::Local<v8::Object>> &buffersToPersist);
+
   enum class ImageType {
-    UNKNOWN,
     JPEG,
     PNG,
     WEBP,
     TIFF,
+    GIF,
+    SVG,
+    PDF,
     MAGICK,
     OPENSLIDE,
     PPM,
     FITS,
-    RAW
+    VIPS,
+    RAW,
+    UNKNOWN
   };
 
   // How many tasks are in the queue?
@@ -36,6 +122,7 @@ namespace sharp {
   bool IsTiff(std::string const &str);
   bool IsDz(std::string const &str);
   bool IsDzZip(std::string const &str);
+  bool IsV(std::string const &str);
 
   /*
     Provide a string identifier for the given image type.
@@ -52,6 +139,11 @@ namespace sharp {
   */
   ImageType DetermineImageType(char const *file);
 
+  /*
+    Open an image from the given InputDescriptor (filesystem, compressed buffer, raw pixel data)
+  */
+  std::tuple<VImage, ImageType> OpenInput(InputDescriptor *descriptor, VipsAccess accessMethod);
+
   /*
     Does this image have an embedded profile?
   */
@@ -91,13 +183,35 @@ namespace sharp {
   /*
     Set pixels/mm resolution based on a pixels/inch density.
   */
-  void SetDensity(VImage image, const int density);
+  void SetDensity(VImage image, const double density);
+
+  /*
+    Check the proposed format supports the current dimensions.
+  */
+  void AssertImageTypeDimensions(VImage image, ImageType const imageType);
 
   /*
     Called when a Buffer undergoes GC, required to support mixed runtime libraries in Windows
   */
   void FreeCallback(char* data, void* hint);
 
+  /*
+    Called with warnings from the glib-registered "VIPS" domain
+  */
+  void VipsWarningCallback(char const* log_domain, GLogLevelFlags log_level, char const* message, void* ignore);
+
+  /*
+    Pop the oldest warning message from the queue
+  */
+  std::string VipsWarningPop();
+
+  /*
+    Calculate the (left, top) coordinates of the output image
+    within the input image, applying the given gravity during an embed.
+  */
+  std::tuple<int, int> CalculateEmbedPosition(int const inWidth, int const inHeight,
+    int const outWidth, int const outHeight, int const gravity);
+
   /*
     Calculate the (left, top) coordinates of the output image
     within the input image, applying the given gravity.
@@ -105,6 +219,44 @@ namespace sharp {
   std::tuple<int, int> CalculateCrop(int const inWidth, int const inHeight,
     int const outWidth, int const outHeight, int const gravity);
 
+  /*
+    Calculate the (left, top) coordinates of the output image
+    within the input image, applying the given x and y offsets of the output image.
+  */
+  std::tuple<int, int> CalculateCrop(int const inWidth, int const inHeight,
+    int const outWidth, int const outHeight, int const x, int const y);
+
+  /*
+    Are pixel values in this image 16-bit integer?
+  */
+  bool Is16Bit(VipsInterpretation const interpretation);
+
+  /*
+    Return the image alpha maximum. Useful for combining alpha bands. scRGB
+    images are 0 - 1 for image data, but the alpha is 0 - 255.
+  */
+  double MaximumImageAlpha(VipsInterpretation const interpretation);
+
+  /*
+    Get boolean operation type from string
+  */
+  VipsOperationBoolean GetBooleanOperation(std::string const opStr);
+
+  /*
+    Get interpretation type from string
+  */
+  VipsInterpretation GetInterpretation(std::string const typeStr);
+
+  /*
+    Convert RGBA value to another colourspace
+  */
+  std::vector<double> GetRgbaAsColourspace(std::vector<double> const rgba, VipsInterpretation const interpretation);
+
+  /*
+    Apply the alpha channel to a given colour
+   */
+  std::tuple<VImage, std::vector<double>> ApplyAlpha(VImage image, std::vector<double> colour);
+
 }  // namespace sharp
 
 #endif  // SRC_COMMON_H_

src/libvips/cplusplus/VImage.cpp

@@ -2,6 +2,10 @@
  *
  * 30/12/14
  * 	- allow set enum value from string
+ * 10/6/16
+ * 	- missing implementation of VImage::write()
+ * 11/6/16
+ * 	- added arithmetic assignment overloads, += etc. 
  */
 
 /*
@@ -201,6 +205,30 @@ VOption::set( const char *name, std::vector<double> value )
 	return( this );
 }
 
+// input int array
+VOption *
+VOption::set( const char *name, std::vector<int> value )
+{
+	Pair *pair = new Pair( name );
+
+	int *array;
+	unsigned int i; 
+
+	pair->input = true;
+
+	g_value_init( &pair->value, VIPS_TYPE_ARRAY_INT );
+	vips_value_set_array_int( &pair->value, NULL,
+		static_cast< int >( value.size() ) );
+	array = vips_value_get_array_int( &pair->value, NULL ); 
+
+	for( i = 0; i < value.size(); i++ )  
+		array[i] = value[i]; 
+
+	options.push_back( pair );
+
+	return( this );
+}
+
 // input image array
 VOption *
 VOption::set( const char *name, std::vector<VImage> value )
@@ -346,7 +374,7 @@ set_property( VipsObject *object, const char *name, const GValue *value )
 
 	if( vips_object_get_argument( object, name, 
 		&pspec, &argument_class, &argument_instance ) ) {
-		vips_warn( NULL, "%s", vips_error_buffer() );
+		g_warning( "%s", vips_error_buffer() );
 		vips_error_clear();
 		return;
 	}
@@ -360,7 +388,7 @@ set_property( VipsObject *object, const char *name, const GValue *value )
 
 		if( (enum_value = vips_enum_from_nick( object_class->nickname, 
 			pspec_type, g_value_get_string( value ) )) < 0 ) {
-			vips_warn( NULL, "%s", vips_error_buffer() );
+			g_warning( "%s", vips_error_buffer() );
 			vips_error_clear();
 			return;
 		}
@@ -457,12 +485,11 @@ VImage::call_option_string( const char *operation_name,
 {
 	VipsOperation *operation;
 
-	VIPS_DEBUG_MSG( "vips_call_by_name: starting for %s ...\n", 
+	VIPS_DEBUG_MSG( "call_option_string: starting for %s ...\n", 
 		operation_name );
 
 	if( !(operation = vips_operation_new( operation_name )) ) {
-		if( options )
+		delete options;
-			delete options;
 		throw( VError() ); 
 	}
 
@@ -485,6 +512,7 @@ VImage::call_option_string( const char *operation_name,
 	 */
 	if( vips_cache_operation_buildp( &operation ) ) {
 		vips_object_unref_outputs( VIPS_OBJECT( operation ) );
+		g_object_unref( operation ); 
 		delete options; 
 		throw( VError() ); 
 	}
@@ -560,34 +588,6 @@ VImage::new_from_buffer( void *buf, size_t len, const char *option_string,
 	return( out );
 }
 
-VImage 
-VImage::new_from_image( std::vector<double> pixel )
-{
-	VImage onepx = VImage::black( 1, 1, 
-		VImage::option()->set( "bands", bands() ) ); 
-
-	onepx = onepx.linear( to_vectorv( 1, 1.0 ), pixel ).cast( format() );
-
-	VImage big = onepx.embed( 0, 0, width(), height(), 
-		VImage::option()->set( "extend", VIPS_EXTEND_COPY ) ); 
-
-	big = big.copy( 
-		VImage::option()->
-			set( "interpretation", interpretation() )->
-			set( "xres", xres() )->
-			set( "yres", yres() )->
-			set( "xoffset", xres() )->
-			set( "yoffset", yres() ) ); 
-
-	return( big ); 
-}
-
-VImage 
-VImage::new_from_image( double pixel )
-{
-	return( new_from_image( to_vectorv( 1, pixel ) ) ); 
-}
-
 VImage 
 VImage::new_matrix( int width, int height ) 
 {
@@ -612,8 +612,17 @@ VImage::new_matrixv( int width, int height, ... )
 	return( matrix ); 
 }
 
+VImage
+VImage::write( VImage out ) const
+{
+	if( vips_image_write( this->get_image(), out.get_image() ) )
+		throw VError(); 
+
+	return( out ); 
+}
+
 void 
-VImage::write_to_file( const char *name, VOption *options )
+VImage::write_to_file( const char *name, VOption *options ) const
 {
 	char filename[VIPS_PATH_MAX];
 	char option_string[VIPS_PATH_MAX];
@@ -633,7 +642,7 @@ VImage::write_to_file( const char *name, VOption *options )
 
 void 
 VImage::write_to_buffer( const char *suffix, void **buf, size_t *size, 
-	VOption *options )
+	VOption *options ) const
 {
 	char filename[VIPS_PATH_MAX];
 	char option_string[VIPS_PATH_MAX];
@@ -666,7 +675,7 @@ VImage::write_to_buffer( const char *suffix, void **buf, size_t *size,
 #include "vips-operators.cpp"
 
 std::vector<VImage> 
-VImage::bandsplit( VOption *options )
+VImage::bandsplit( VOption *options ) const
 {
 	std::vector<VImage> b; 
 
@@ -677,16 +686,27 @@ VImage::bandsplit( VOption *options )
 }
 
 VImage 
-VImage::bandjoin( VImage other, VOption *options )
+VImage::bandjoin( VImage other, VOption *options ) const
 {
-    VImage v[2] = { *this, other }; 
+	VImage v[2] = { *this, other }; 
-    std::vector<VImage> vec( v, v + VIPS_NUMBER( v ) );
+	std::vector<VImage> vec( v, v + VIPS_NUMBER( v ) );
 
-    return( bandjoin( vec, options ) ); 
+	return( bandjoin( vec, options ) ); 
+}
+
+VImage 
+VImage::composite( VImage other, VipsBlendMode mode, VOption *options ) const
+{
+	VImage v[2] = { *this, other }; 
+	std::vector<VImage> ivec( v, v + VIPS_NUMBER( v ) );
+	int m[1] = { static_cast<int>( mode ) }; 
+	std::vector<int> mvec( m, m + VIPS_NUMBER( m ) );
+
+	return( composite( ivec, mvec, options ) ); 
 }
 
 std::complex<double> 
-VImage::minpos( VOption *options )
+VImage::minpos( VOption *options ) const
 {
 	double x, y;
 
@@ -699,7 +719,7 @@ VImage::minpos( VOption *options )
 }
 
 std::complex<double> 
-VImage::maxpos( VOption *options )
+VImage::maxpos( VOption *options ) const
 {
 	double x, y;
 
@@ -711,4 +731,686 @@ VImage::maxpos( VOption *options )
 	return( std::complex<double>( x, y ) ); 
 }
 
+// Operator overloads
+
+VImage 
+VImage::operator[]( int index ) const
+{
+	return( this->extract_band( index ) ); 
+}
+
+std::vector<double> 
+VImage::operator()( int x, int y ) const
+{
+	return( this->getpoint( x, y ) ); 
+}
+
+VImage 
+operator+( const VImage a, const VImage b )
+{
+	return( a.add( b ) );
+}
+
+VImage 
+operator+( double a, const VImage b ) 
+{
+	return( b.linear( 1.0, a ) ); 
+}
+
+VImage 
+operator+( const VImage a, double b ) 
+{ 
+	return( a.linear( 1.0, b ) ); 
+}
+
+VImage 
+operator+( const std::vector<double> a, const VImage b ) 
+{
+	return( b.linear( 1.0, a ) ); 
+}
+
+VImage 
+operator+( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.linear( 1.0, b ) ); 
+}
+
+VImage & 
+operator+=( VImage &a, const VImage b )
+{
+	return( a = a + b ); 
+}
+
+VImage & 
+operator+=( VImage &a, const double b )
+{
+	return( a = a + b ); 
+}
+
+VImage & 
+operator+=( VImage &a, const std::vector<double> b )
+{
+	return( a = a + b ); 
+}
+
+VImage 
+operator-( const VImage a, const VImage b ) 
+{
+	return( a.subtract( b ) );
+}
+
+VImage 
+operator-( double a, const VImage b ) 
+{
+	return( b.linear( -1.0, a ) ); 
+}
+
+VImage 
+operator-( const VImage a, double b ) 
+{ 
+	return( a.linear( 1.0, -b ) ); 
+}
+
+VImage 
+operator-( const std::vector<double> a, const VImage b ) 
+{
+	return( b.linear( -1.0, a ) ); 
+}
+
+VImage 
+operator-( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.linear( 1.0, vips::negate( b ) ) ); 
+}
+
+VImage & 
+operator-=( VImage &a, const VImage b )
+{
+	return( a = a - b ); 
+}
+
+VImage & 
+operator-=( VImage &a, const double b )
+{
+	return( a = a - b ); 
+}
+
+VImage & 
+operator-=( VImage &a, const std::vector<double> b )
+{
+	return( a = a - b ); 
+}
+
+VImage 
+operator-( const VImage a ) 
+{ 
+	return( a * -1 );
+}
+
+VImage 
+operator*( const VImage a, const VImage b ) 
+{
+	return( a.multiply( b ) );
+}
+
+VImage 
+operator*( double a, const VImage b ) 
+{
+	return( b.linear( a, 0.0 ) ); 
+}
+
+VImage 
+operator*( const VImage a, double b ) 
+{ 
+	return( a.linear( b, 0.0 ) ); 
+}
+
+VImage 
+operator*( const std::vector<double> a, const VImage b ) 
+{
+	return( b.linear( a, 0.0 ) ); 
+}
+
+VImage 
+operator*( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.linear( b, 0.0 ) ); 
+}
+
+VImage & 
+operator*=( VImage &a, const VImage b )
+{
+	return( a = a * b ); 
+}
+
+VImage & 
+operator*=( VImage &a, const double b )
+{
+	return( a = a * b ); 
+}
+
+VImage & 
+operator*=( VImage &a, const std::vector<double> b )
+{
+	return( a = a * b ); 
+}
+
+VImage 
+operator/( const VImage a, const VImage b ) 
+{
+	return( a.divide( b ) );
+}
+
+VImage 
+operator/( double a, const VImage b ) 
+{
+	return( b.pow( -1.0 ).linear( a, 0.0 ) ); 
+}
+
+VImage 
+operator/( const VImage a, double b ) 
+{ 
+	return( a.linear( 1.0 / b, 0.0 ) ); 
+}
+
+VImage 
+operator/( const std::vector<double> a, const VImage b ) 
+{
+	return( b.pow( -1.0 ).linear( a, 0.0 ) ); 
+}
+
+VImage 
+operator/( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.linear( vips::invert( b ), 0.0 ) ); 
+}
+
+VImage & 
+operator/=( VImage &a, const VImage b )
+{
+	return( a = a / b ); 
+}
+
+VImage & 
+operator/=( VImage &a, const double b )
+{
+	return( a = a / b ); 
+}
+
+VImage & 
+operator/=( VImage &a, const std::vector<double> b )
+{
+	return( a = a / b ); 
+}
+
+VImage 
+operator%( const VImage a, const VImage b ) 
+{
+	return( a.remainder( b ) );
+}
+
+VImage 
+operator%( const VImage a, const double b ) 
+{ 
+	return( a.remainder_const( to_vector( b ) ) ); 
+}
+
+VImage 
+operator%( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.remainder_const( b ) ); 
+}
+
+VImage & 
+operator%=( VImage &a, const VImage b )
+{
+	return( a = a % b ); 
+}
+
+VImage & 
+operator%=( VImage &a, const double b )
+{
+	return( a = a % b ); 
+}
+
+VImage & 
+operator%=( VImage &a, const std::vector<double> b )
+{
+	return( a = a % b ); 
+}
+
+VImage 
+operator<( const VImage a, const VImage b ) 
+{
+	return( a.relational( b, VIPS_OPERATION_RELATIONAL_LESS ) );
+}
+
+VImage 
+operator<( const double a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_MORE, 
+		to_vector( a ) ) ); 
+}
+
+VImage 
+operator<( const VImage a, const double b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_LESS, 
+		to_vector( b ) ) );  
+}
+
+VImage 
+operator<( const std::vector<double> a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_MORE, 
+		a ) );  
+}
+
+VImage 
+operator<( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_LESS, 
+		b ) ); 
+}
+
+VImage 
+operator<=( const VImage a, const VImage b ) 
+{
+	return( a.relational( b, VIPS_OPERATION_RELATIONAL_LESSEQ ) );
+}
+
+VImage 
+operator<=( const double a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_MOREEQ, 
+		to_vector( a ) ) );  
+}
+
+VImage 
+operator<=( const VImage a, const double b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_LESSEQ, 
+		to_vector( b ) ) );  
+}
+
+VImage 
+operator<=( const std::vector<double> a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_MOREEQ, 
+		a ) );
+}
+
+VImage 
+operator<=( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_LESSEQ,
+		b ) );
+}
+
+VImage 
+operator>( const VImage a, const VImage b ) 
+{
+	return( a.relational( b, VIPS_OPERATION_RELATIONAL_MORE ) );
+}
+
+VImage 
+operator>( const double a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_LESS, 
+		to_vector( a ) ) ); 
+}
+
+VImage 
+operator>( const VImage a, const double b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_MORE, 
+		to_vector( b ) ) );
+}
+
+VImage 
+operator>( const std::vector<double> a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_LESS, 
+		a ) );
+}
+
+VImage 
+operator>( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_MORE, 
+		b ) );
+}
+
+VImage 
+operator>=( const VImage a, const VImage b ) 
+{
+	return( a.relational( b, VIPS_OPERATION_RELATIONAL_MOREEQ ) );
+}
+
+VImage 
+operator>=( const double a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_LESSEQ, 
+		to_vector( a ) ) );  
+}
+
+VImage 
+operator>=( const VImage a, const double b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_MOREEQ, 
+		to_vector( b ) ) ); 
+}
+
+VImage 
+operator>=( const std::vector<double> a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_LESSEQ, 
+		a ) );
+}
+
+VImage 
+operator>=( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_MOREEQ, 
+		b ) );
+}
+
+VImage 
+operator==( const VImage a, const VImage b ) 
+{
+	return( a.relational( b, VIPS_OPERATION_RELATIONAL_EQUAL ) );
+}
+
+VImage 
+operator==( const double a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_EQUAL, 
+		to_vector( a ) ) );
+}
+
+VImage 
+operator==( const VImage a, const double b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_EQUAL, 
+		to_vector( b ) ) );
+}
+
+VImage 
+operator==( const std::vector<double> a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_EQUAL, 
+		a ) );
+}
+
+VImage 
+operator==( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_EQUAL, 
+		b ) );
+}
+
+VImage 
+operator!=( const VImage a, const VImage b ) 
+{
+	return( a.relational( b, VIPS_OPERATION_RELATIONAL_NOTEQ ) );
+}
+
+VImage 
+operator!=( const double a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_NOTEQ,
+		to_vector( a ) ) );  
+}
+
+VImage 
+operator!=( const VImage a, const double b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_NOTEQ, 
+		to_vector( b ) ) );
+}
+
+VImage 
+operator!=( const std::vector<double> a, const VImage b ) 
+{
+	return( b.relational_const( VIPS_OPERATION_RELATIONAL_NOTEQ,
+		a ) );
+}
+
+VImage 
+operator!=( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.relational_const( VIPS_OPERATION_RELATIONAL_NOTEQ,
+		b ) );
+}
+
+VImage 
+operator&( const VImage a, const VImage b ) 
+{
+	return( a.boolean( b, VIPS_OPERATION_BOOLEAN_AND ) );
+}
+
+VImage 
+operator&( const double a, const VImage b ) 
+{
+	return( b.boolean_const( VIPS_OPERATION_BOOLEAN_AND, 
+		to_vector( a ) ) );  
+}
+
+VImage 
+operator&( const VImage a, const double b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_AND, 
+		to_vector( b ) ) );
+}
+
+VImage 
+operator&( const std::vector<double> a, const VImage b ) 
+{
+	return( b.boolean_const( VIPS_OPERATION_BOOLEAN_AND, a ) );
+}
+
+VImage 
+operator&( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_AND, b ) );
+}
+
+VImage & 
+operator&=( VImage &a, const VImage b )
+{
+	return( a = a & b ); 
+}
+
+VImage & 
+operator&=( VImage &a, const double b )
+{
+	return( a = a & b ); 
+}
+
+VImage & 
+operator&=( VImage &a, const std::vector<double> b )
+{
+	return( a = a & b ); 
+}
+
+VImage 
+operator|( const VImage a, const VImage b ) 
+{
+	return( a.boolean( b, VIPS_OPERATION_BOOLEAN_OR ) );
+}
+
+VImage 
+operator|( const double a, const VImage b ) 
+{
+	return( b.boolean_const( VIPS_OPERATION_BOOLEAN_OR, 
+		to_vector( a ) ) ); 
+}
+
+VImage 
+operator|( const VImage a, const double b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_OR, 
+		to_vector( b ) ) );
+}
+
+VImage 
+operator|( const std::vector<double> a, const VImage b ) 
+{
+	return( b.boolean_const( VIPS_OPERATION_BOOLEAN_OR, 
+		a ) );
+}
+
+VImage 
+operator|( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_OR, 
+		b ) );
+}
+
+VImage & 
+operator|=( VImage &a, const VImage b )
+{
+	return( a = a | b ); 
+}
+
+VImage & 
+operator|=( VImage &a, const double b )
+{
+	return( a = a | b ); 
+}
+
+VImage & 
+operator|=( VImage &a, const std::vector<double> b )
+{
+	return( a = a | b ); 
+}
+
+VImage 
+operator^( const VImage a, const VImage b ) 
+{
+	return( a.boolean( b, VIPS_OPERATION_BOOLEAN_EOR ) );
+}
+
+VImage 
+operator^( const double a, const VImage b ) 
+{
+	return( b.boolean_const( VIPS_OPERATION_BOOLEAN_EOR, 
+		to_vector( a ) ) ); 
+}
+
+VImage 
+operator^( const VImage a, const double b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_EOR, 
+		to_vector( b ) ) ); 
+}
+
+VImage 
+operator^( const std::vector<double> a, const VImage b ) 
+{
+	return( b.boolean_const( VIPS_OPERATION_BOOLEAN_EOR,
+		a ) );
+}
+
+VImage 
+operator^( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_EOR,
+		b ) );
+}
+
+VImage & 
+operator^=( VImage &a, const VImage b )
+{
+	return( a = a ^ b ); 
+}
+
+VImage & 
+operator^=( VImage &a, const double b )
+{
+	return( a = a ^ b ); 
+}
+
+VImage & 
+operator^=( VImage &a, const std::vector<double> b )
+{
+	return( a = a ^ b ); 
+}
+
+VImage 
+operator<<( const VImage a, const VImage b ) 
+{
+	return( a.boolean( b, VIPS_OPERATION_BOOLEAN_LSHIFT ) );
+}
+
+VImage 
+operator<<( const VImage a, const double b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_LSHIFT, 
+		to_vector( b ) ) ); 
+}
+
+VImage 
+operator<<( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_LSHIFT, 
+		b ) ); 
+}
+
+VImage & 
+operator<<=( VImage &a, const VImage b )
+{
+	return( a = a << b ); 
+}
+
+VImage & 
+operator<<=( VImage &a, const double b )
+{
+	return( a = a << b ); 
+}
+
+VImage & 
+operator<<=( VImage &a, const std::vector<double> b )
+{
+	return( a = a << b ); 
+}
+
+VImage 
+operator>>( const VImage a, const VImage b ) 
+{
+	return( a.boolean( b, VIPS_OPERATION_BOOLEAN_RSHIFT ) );
+}
+
+VImage 
+operator>>( const VImage a, const double b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_RSHIFT, 
+		to_vector( b ) ) );  
+}
+
+VImage 
+operator>>( const VImage a, const std::vector<double> b ) 
+{ 
+	return( a.boolean_const( VIPS_OPERATION_BOOLEAN_RSHIFT,
+		b ) ); 
+}
+
+VImage & 
+operator>>=( VImage &a, const VImage b )
+{
+	return( a = a << b ); 
+}
+
+VImage & 
+operator>>=( VImage &a, const double b )
+{
+	return( a = a << b ); 
+}
+
+VImage & 
+operator>>=( VImage &a, const std::vector<double> b )
+{
+	return( a = a << b ); 
+}
+
 VIPS_NAMESPACE_END

src/metadata.cc

@@ -1,135 +1,86 @@
-#include <node.h>
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
-#include <vips/vips8>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
 
-#include "nan.h"
+#include <numeric>
+#include <vector>
+
+#include <node.h>
+#include <nan.h>
+#include <vips/vips8>
 
 #include "common.h"
 #include "metadata.h"
 
-using v8::Handle;
+class MetadataWorker : public Nan::AsyncWorker {
-using v8::Local;
-using v8::Value;
-using v8::Object;
-using v8::Number;
-using v8::String;
-using v8::Boolean;
-using v8::Function;
-using v8::Exception;
-
-using Nan::AsyncQueueWorker;
-using Nan::AsyncWorker;
-using Nan::Callback;
-using Nan::HandleScope;
-using Nan::Utf8String;
-using Nan::Has;
-using Nan::Get;
-using Nan::Set;
-using Nan::New;
-using Nan::NewBuffer;
-using Nan::Null;
-using Nan::Error;
-
-using vips::VImage;
-using vips::VError;
-
-using sharp::ImageType;
-using sharp::ImageTypeId;
-using sharp::DetermineImageType;
-using sharp::HasProfile;
-using sharp::HasAlpha;
-using sharp::ExifOrientation;
-using sharp::HasDensity;
-using sharp::GetDensity;
-using sharp::FreeCallback;
-using sharp::counterQueue;
-
-struct MetadataBaton {
-  // Input
-  std::string fileIn;
-  char *bufferIn;
-  size_t bufferInLength;
-  // Output
-  std::string format;
-  int width;
-  int height;
-  std::string space;
-  int channels;
-  int density;
-  bool hasProfile;
-  bool hasAlpha;
-  int orientation;
-  char *exif;
-  size_t exifLength;
-  char *icc;
-  size_t iccLength;
-  std::string err;
-
-  MetadataBaton():
-    bufferInLength(0),
-    density(0),
-    orientation(0),
-    exifLength(0),
-    iccLength(0) {}
-};
-
-class MetadataWorker : public AsyncWorker {
  public:
-  MetadataWorker(Callback *callback, MetadataBaton *baton, const Local<Object> &bufferIn) :
+  MetadataWorker(
-    AsyncWorker(callback), baton(baton) {
+    Nan::Callback *callback, MetadataBaton *baton, Nan::Callback *debuglog,
-      if (baton->bufferInLength > 0) {
+    std::vector<v8::Local<v8::Object>> const buffersToPersist) :
-        SaveToPersistent("bufferIn", bufferIn);
+    Nan::AsyncWorker(callback, "sharp:MetadataWorker"),
-      }
+    baton(baton), debuglog(debuglog),
-    }
+    buffersToPersist(buffersToPersist) {
+    // Protect Buffer objects from GC, keyed on index
+    std::accumulate(buffersToPersist.begin(), buffersToPersist.end(), 0,
+      [this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
+        SaveToPersistent(index, buffer);
+        return index + 1;
+      });
+  }
   ~MetadataWorker() {}
 
   void Execute() {
     // Decrement queued task counter
-    g_atomic_int_dec_and_test(&counterQueue);
+    g_atomic_int_dec_and_test(&sharp::counterQueue);
 
-    ImageType imageType = ImageType::UNKNOWN;
+    vips::VImage image;
-    VImage image;
+    sharp::ImageType imageType = sharp::ImageType::UNKNOWN;
-    if (baton->bufferInLength > 0) {
+    try {
-      // From buffer
+      std::tie(image, imageType) = OpenInput(baton->input, VIPS_ACCESS_SEQUENTIAL);
-      imageType = DetermineImageType(baton->bufferIn, baton->bufferInLength);
+    } catch (vips::VError const &err) {
-      if (imageType != ImageType::UNKNOWN) {
+      (baton->err).append(err.what());
-        try {
-          image = VImage::new_from_buffer(baton->bufferIn, baton->bufferInLength, nullptr);
-        } catch (...) {
-          (baton->err).append("Input buffer has corrupt header");
-          imageType = ImageType::UNKNOWN;
-        }
-      } else {
-        (baton->err).append("Input buffer contains unsupported image format");
-      }
-    } else {
-      // From file
-      imageType = DetermineImageType(baton->fileIn.data());
-      if (imageType != ImageType::UNKNOWN) {
-        try {
-          image = VImage::new_from_file(baton->fileIn.data());
-        } catch (...) {
-          (baton->err).append("Input file has corrupt header");
-          imageType = ImageType::UNKNOWN;
-        }
-      } else {
-        (baton->err).append("Input file is missing or of an unsupported image format");
-      }
     }
-    if (imageType != ImageType::UNKNOWN) {
+    if (imageType != sharp::ImageType::UNKNOWN) {
       // Image type
-      baton->format = ImageTypeId(imageType);
+      baton->format = sharp::ImageTypeId(imageType);
       // VipsImage attributes
       baton->width = image.width();
       baton->height = image.height();
       baton->space = vips_enum_nick(VIPS_TYPE_INTERPRETATION, image.interpretation());
       baton->channels = image.bands();
-      if (HasDensity(image)) {
+      baton->depth = vips_enum_nick(VIPS_TYPE_BAND_FORMAT, image.format());
-        baton->density = GetDensity(image);
+      if (sharp::HasDensity(image)) {
+        baton->density = sharp::GetDensity(image);
       }
-      baton->hasProfile = HasProfile(image);
+      if (image.get_typeof("jpeg-chroma-subsample") == VIPS_TYPE_REF_STRING) {
+        baton->chromaSubsampling = image.get_string("jpeg-chroma-subsample");
+      }
+      if (image.get_typeof("interlaced") == G_TYPE_INT) {
+        baton->isProgressive = image.get_int("interlaced") == 1;
+      }
+      if (image.get_typeof("palette-bit-depth") == G_TYPE_INT) {
+        baton->paletteBitDepth = image.get_int("palette-bit-depth");
+      }
+      if (image.get_typeof(VIPS_META_N_PAGES) == G_TYPE_INT) {
+        baton->pages = image.get_int(VIPS_META_N_PAGES);
+      }
+      if (image.get_typeof(VIPS_META_PAGE_HEIGHT) == G_TYPE_INT) {
+        baton->pageHeight = image.get_int(VIPS_META_PAGE_HEIGHT);
+      }
+      baton->hasProfile = sharp::HasProfile(image);
       // Derived attributes
-      baton->hasAlpha = HasAlpha(image);
+      baton->hasAlpha = sharp::HasAlpha(image);
-      baton->orientation = ExifOrientation(image);
+      baton->orientation = sharp::ExifOrientation(image);
       // EXIF
       if (image.get_typeof(VIPS_META_EXIF_NAME) == VIPS_TYPE_BLOB) {
         size_t exifLength;
@@ -146,88 +97,143 @@ class MetadataWorker : public AsyncWorker {
         memcpy(baton->icc, icc, iccLength);
         baton->iccLength = iccLength;
       }
+      // IPTC
+      if (image.get_typeof(VIPS_META_IPTC_NAME) == VIPS_TYPE_BLOB) {
+        size_t iptcLength;
+        void const *iptc = image.get_blob(VIPS_META_IPTC_NAME, &iptcLength);
+        baton->iptc = static_cast<char *>(g_malloc(iptcLength));
+        memcpy(baton->iptc, iptc, iptcLength);
+        baton->iptcLength = iptcLength;
+      }
+      // XMP
+      if (image.get_typeof(VIPS_META_XMP_NAME) == VIPS_TYPE_BLOB) {
+        size_t xmpLength;
+        void const *xmp = image.get_blob(VIPS_META_XMP_NAME, &xmpLength);
+        baton->xmp = static_cast<char *>(g_malloc(xmpLength));
+        memcpy(baton->xmp, xmp, xmpLength);
+        baton->xmpLength = xmpLength;
+      }
     }
+
     // Clean up
     vips_error_clear();
     vips_thread_shutdown();
   }
 
-  void HandleOKCallback () {
+  void HandleOKCallback() {
-    HandleScope();
+    using Nan::New;
+    using Nan::Set;
+    Nan::HandleScope();
 
-    Local<Value> argv[2] = { Null(), Null() };
+    v8::Local<v8::Value> argv[2] = { Nan::Null(), Nan::Null() };
     if (!baton->err.empty()) {
-      // Error
+      argv[0] = Nan::Error(baton->err.data());
-      argv[0] = Error(baton->err.data());
     } else {
       // Metadata Object
-      Local<Object> info = New<Object>();
+      v8::Local<v8::Object> info = New<v8::Object>();
-      Set(info, New("format").ToLocalChecked(), New<String>(baton->format).ToLocalChecked());
+      Set(info, New("format").ToLocalChecked(), New<v8::String>(baton->format).ToLocalChecked());
-      Set(info, New("width").ToLocalChecked(), New<Number>(baton->width));
+      if (baton->input->bufferLength > 0) {
-      Set(info, New("height").ToLocalChecked(), New<Number>(baton->height));
+        Set(info, New("size").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(baton->input->bufferLength)));
-      Set(info, New("space").ToLocalChecked(), New<String>(baton->space).ToLocalChecked());
-      Set(info, New("channels").ToLocalChecked(), New<Number>(baton->channels));
-      if (baton->density > 0) {
-        Set(info, New("density").ToLocalChecked(), New<Number>(baton->density));
       }
-      Set(info, New("hasProfile").ToLocalChecked(), New<Boolean>(baton->hasProfile));
+      Set(info, New("width").ToLocalChecked(), New<v8::Uint32>(baton->width));
-      Set(info, New("hasAlpha").ToLocalChecked(), New<Boolean>(baton->hasAlpha));
+      Set(info, New("height").ToLocalChecked(), New<v8::Uint32>(baton->height));
+      Set(info, New("space").ToLocalChecked(), New<v8::String>(baton->space).ToLocalChecked());
+      Set(info, New("channels").ToLocalChecked(), New<v8::Uint32>(baton->channels));
+      Set(info, New("depth").ToLocalChecked(), New<v8::String>(baton->depth).ToLocalChecked());
+      if (baton->density > 0) {
+        Set(info, New("density").ToLocalChecked(), New<v8::Uint32>(baton->density));
+      }
+      if (!baton->chromaSubsampling.empty()) {
+        Set(info,
+          New("chromaSubsampling").ToLocalChecked(),
+          New<v8::String>(baton->chromaSubsampling).ToLocalChecked());
+      }
+      Set(info, New("isProgressive").ToLocalChecked(), New<v8::Boolean>(baton->isProgressive));
+      if (baton->paletteBitDepth > 0) {
+        Set(info, New("paletteBitDepth").ToLocalChecked(), New<v8::Uint32>(baton->paletteBitDepth));
+      }
+      if (baton->pages > 0) {
+        Set(info, New("pages").ToLocalChecked(), New<v8::Uint32>(baton->pages));
+      }
+      if (baton->pageHeight > 0) {
+        Set(info, New("pageHeight").ToLocalChecked(), New<v8::Uint32>(baton->pageHeight));
+      }
+      Set(info, New("hasProfile").ToLocalChecked(), New<v8::Boolean>(baton->hasProfile));
+      Set(info, New("hasAlpha").ToLocalChecked(), New<v8::Boolean>(baton->hasAlpha));
       if (baton->orientation > 0) {
-        Set(info, New("orientation").ToLocalChecked(), New<Number>(baton->orientation));
+        Set(info, New("orientation").ToLocalChecked(), New<v8::Uint32>(baton->orientation));
       }
       if (baton->exifLength > 0) {
         Set(info,
           New("exif").ToLocalChecked(),
-          NewBuffer(baton->exif, baton->exifLength, FreeCallback, nullptr).ToLocalChecked()
+          Nan::NewBuffer(baton->exif, baton->exifLength, sharp::FreeCallback, nullptr).ToLocalChecked());
-        );
       }
       if (baton->iccLength > 0) {
         Set(info,
           New("icc").ToLocalChecked(),
-          NewBuffer(baton->icc, baton->iccLength, FreeCallback, nullptr).ToLocalChecked()
+          Nan::NewBuffer(baton->icc, baton->iccLength, sharp::FreeCallback, nullptr).ToLocalChecked());
-        );
+      }
+      if (baton->iptcLength > 0) {
+        Set(info,
+          New("iptc").ToLocalChecked(),
+          Nan::NewBuffer(baton->iptc, baton->iptcLength, sharp::FreeCallback, nullptr).ToLocalChecked());
+      }
+      if (baton->xmpLength > 0) {
+        Set(info,
+          New("xmp").ToLocalChecked(),
+          Nan::NewBuffer(baton->xmp, baton->xmpLength, sharp::FreeCallback, nullptr).ToLocalChecked());
       }
       argv[1] = info;
     }
 
-    // Dispose of Persistent wrapper around input Buffer so it can be garbage collected
+    // Dispose of Persistent wrapper around input Buffers so they can be garbage collected
-    if (baton->bufferInLength > 0) {
+    std::accumulate(buffersToPersist.begin(), buffersToPersist.end(), 0,
-      GetFromPersistent("bufferIn");
+      [this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
-    }
+        GetFromPersistent(index);
+        return index + 1;
+      });
+    delete baton->input;
     delete baton;
 
+    // Handle warnings
+    std::string warning = sharp::VipsWarningPop();
+    while (!warning.empty()) {
+      v8::Local<v8::Value> message[1] = { New(warning).ToLocalChecked() };
+      debuglog->Call(1, message, async_resource);
+      warning = sharp::VipsWarningPop();
+    }
+
     // Return to JavaScript
-    callback->Call(2, argv);
+    callback->Call(2, argv, async_resource);
   }
 
  private:
   MetadataBaton* baton;
+  Nan::Callback *debuglog;
+  std::vector<v8::Local<v8::Object>> buffersToPersist;
 };
 
 /*
   metadata(options, callback)
 */
 NAN_METHOD(metadata) {
-  HandleScope();
+  // Input Buffers must not undergo GC compaction during processing
+  std::vector<v8::Local<v8::Object>> buffersToPersist;
 
   // V8 objects are converted to non-V8 types held in the baton struct
   MetadataBaton *baton = new MetadataBaton;
-  Local<Object> options = info[0].As<Object>();
+  v8::Local<v8::Object> options = info[0].As<v8::Object>();
 
-  // Input filename
+  // Input
-  baton->fileIn = *Utf8String(Get(options, New("fileIn").ToLocalChecked()).ToLocalChecked());
+  baton->input = sharp::CreateInputDescriptor(sharp::AttrAs<v8::Object>(options, "input"), buffersToPersist);
-  // Input Buffer object
+
-  Local<Object> bufferIn;
+  // Function to notify of libvips warnings
-  if (node::Buffer::HasInstance(Get(options, New("bufferIn").ToLocalChecked()).ToLocalChecked())) {
+  Nan::Callback *debuglog = new Nan::Callback(sharp::AttrAs<v8::Function>(options, "debuglog"));
-    bufferIn = Get(options, New("bufferIn").ToLocalChecked()).ToLocalChecked().As<Object>();
-    baton->bufferInLength = node::Buffer::Length(bufferIn);
-    baton->bufferIn = node::Buffer::Data(bufferIn);
-  }
 
   // Join queue for worker thread
-  Callback *callback = new Callback(info[1].As<Function>());
+  Nan::Callback *callback = new Nan::Callback(info[1].As<v8::Function>());
-  AsyncQueueWorker(new MetadataWorker(callback, baton, bufferIn));
+  Nan::AsyncQueueWorker(new MetadataWorker(callback, baton, debuglog, buffersToPersist));
 
   // Increment queued task counter
-  g_atomic_int_inc(&counterQueue);
+  g_atomic_int_inc(&sharp::counterQueue);
 }

src/metadata.h

@@ -1,7 +1,76 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #ifndef SRC_METADATA_H_
 #define SRC_METADATA_H_
 
-#include "nan.h"
+#include <string>
+#include <nan.h>
+
+#include "./common.h"
+
+struct MetadataBaton {
+  // Input
+  sharp::InputDescriptor *input;
+  // Output
+  std::string format;
+  int width;
+  int height;
+  std::string space;
+  int channels;
+  std::string depth;
+  int density;
+  std::string chromaSubsampling;
+  bool isProgressive;
+  int paletteBitDepth;
+  int pages;
+  int pageHeight;
+  bool hasProfile;
+  bool hasAlpha;
+  int orientation;
+  char *exif;
+  size_t exifLength;
+  char *icc;
+  size_t iccLength;
+  char *iptc;
+  size_t iptcLength;
+  char *xmp;
+  size_t xmpLength;
+  std::string err;
+
+  MetadataBaton():
+    input(nullptr),
+    width(0),
+    height(0),
+    channels(0),
+    density(0),
+    isProgressive(false),
+    paletteBitDepth(0),
+    pages(0),
+    pageHeight(0),
+    hasProfile(false),
+    hasAlpha(false),
+    orientation(0),
+    exif(nullptr),
+    exifLength(0),
+    icc(nullptr),
+    iccLength(0),
+    iptc(nullptr),
+    iptcLength(0),
+    xmp(nullptr),
+    xmpLength(0) {}
+};
 
 NAN_METHOD(metadata);
 

src/operations.cc

@@ -1,5 +1,23 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #include <algorithm>
+#include <functional>
+#include <memory>
 #include <tuple>
+#include <vector>
+
 #include <vips/vips8>
 
 #include "common.h"
@@ -11,37 +29,54 @@ using vips::VError;
 namespace sharp {
 
   /*
-    Alpha composite src over dst with given gravity.
+    Removes alpha channel, if any.
-    Assumes alpha channels are already premultiplied and will be unpremultiplied after.
+  */
+  VImage RemoveAlpha(VImage image) {
+    if (HasAlpha(image)) {
+      image = image.extract_band(0, VImage::option()->set("n", image.bands() - 1));
+    }
+    return image;
+  }
+
+  /*
+    Ensures alpha channel, if missing.
+  */
+  VImage EnsureAlpha(VImage image) {
+    if (!HasAlpha(image)) {
+      std::vector<double> alpha;
+      alpha.push_back(sharp::MaximumImageAlpha(image.interpretation()));
+      image = image.bandjoin_const(alpha);
+    }
+    return image;
+  }
+
+  /*
+    Composite overlayImage over image at given position
+    Assumes alpha channels are already premultiplied and will be unpremultiplied after
    */
-  VImage Composite(VImage src, VImage dst, const int gravity) {
+  VImage Composite(VImage image, VImage overlayImage, int const left, int const top) {
-    using sharp::CalculateCrop;
+    if (HasAlpha(overlayImage)) {
-    using sharp::HasAlpha;
+      // Alpha composite
-
+      if (overlayImage.width() < image.width() || overlayImage.height() < image.height()) {
-    if (!HasAlpha(src)) {
+        // Enlarge overlay
-      throw VError("Overlay image must have an alpha channel");
+        std::vector<double> const background { 0.0, 0.0, 0.0, 0.0 };
-    }
+        overlayImage = overlayImage.embed(left, top, image.width(), image.height(), VImage::option()
-    if (!HasAlpha(dst)) {
+          ->set("extend", VIPS_EXTEND_BACKGROUND)
-      throw VError("Image to be overlaid must have an alpha channel");
+          ->set("background", background));
-    }
+      }
-    if (src.width() > dst.width() || src.height() > dst.height()) {
+      return AlphaComposite(image, overlayImage);
-      throw VError("Overlay image must have same dimensions or smaller");
+    } else {
-    }
+      if (HasAlpha(image)) {
-
+        // Add alpha channel to overlayImage so channels match
-    // Enlarge overlay src, if required
+        double const multiplier = sharp::Is16Bit(overlayImage.interpretation()) ? 256.0 : 1.0;
-    if (src.width() < dst.width() || src.height() < dst.height()) {
+        overlayImage = overlayImage.bandjoin(
-      // Calculate the (left, top) coordinates of the output image within the input image, applying the given gravity.
+          VImage::new_matrix(overlayImage.width(), overlayImage.height()).new_from_image(255 * multiplier));
-      int left;
+      }
-      int top;
+      return image.insert(overlayImage, left, top);
-      std::tie(left, top) = CalculateCrop(dst.width(), dst.height(), src.width(), src.height(), gravity);
+    }
-      // Embed onto transparent background
+  }
-      std::vector<double> background { 0.0, 0.0, 0.0, 0.0 };
-      src = src.embed(left, top, dst.width(), dst.height(), VImage::option()
-        ->set("extend", VIPS_EXTEND_BACKGROUND)
-        ->set("background", background)
-      );
-    }
 
+  VImage AlphaComposite(VImage dst, VImage src) {
     // Split src into non-alpha and alpha channels
     VImage srcWithoutAlpha = src.extract_band(0, VImage::option()->set("n", src.bands() - 1));
     VImage srcAlpha = src[src.bands() - 1] * (1.0 / 255.0);
@@ -55,7 +90,7 @@ namespace sharp {
     //
     // References:
     // - http://en.wikipedia.org/wiki/Alpha_compositing#Alpha_blending
-    // - https://github.com/jcupitt/ruby-vips/issues/28#issuecomment-9014826
+    // - https://github.com/libvips/ruby-vips/issues/28#issuecomment-9014826
     //
     // out_a = src_a + dst_a * (1 - src_a)
     //                         ^^^^^^^^^^^
@@ -81,10 +116,95 @@ namespace sharp {
     return outRGBPremultiplied.bandjoin(outAlphaNormalized * 255.0);
   }
 
+  /*
+    Cutout src over dst with given gravity.
+   */
+  VImage Cutout(VImage mask, VImage dst, const int gravity) {
+    using sharp::CalculateCrop;
+    using sharp::HasAlpha;
+    using sharp::MaximumImageAlpha;
+
+    bool maskHasAlpha = HasAlpha(mask);
+
+    if (!maskHasAlpha && mask.bands() > 1) {
+      throw VError("Overlay image must have an alpha channel or one band");
+    }
+    if (!HasAlpha(dst)) {
+      throw VError("Image to be overlaid must have an alpha channel");
+    }
+    if (mask.width() > dst.width() || mask.height() > dst.height()) {
+      throw VError("Overlay image must have same dimensions or smaller");
+    }
+
+    // Enlarge overlay mask, if required
+    if (mask.width() < dst.width() || mask.height() < dst.height()) {
+      // Calculate the (left, top) coordinates of the output image within the input image, applying the given gravity.
+      int left;
+      int top;
+      std::tie(left, top) = CalculateCrop(dst.width(), dst.height(), mask.width(), mask.height(), gravity);
+      // Embed onto transparent background
+      std::vector<double> background { 0.0, 0.0, 0.0, 0.0 };
+      mask = mask.embed(left, top, dst.width(), dst.height(), VImage::option()
+              ->set("extend", VIPS_EXTEND_BACKGROUND)
+              ->set("background", background));
+    }
+
+    // we use the mask alpha if it has alpha
+    if (maskHasAlpha) {
+      mask = mask.extract_band(mask.bands() - 1, VImage::option()->set("n", 1));;
+    }
+
+    // Split dst into an optional alpha
+    VImage dstAlpha = dst.extract_band(dst.bands() - 1, VImage::option()->set("n", 1));
+
+    // we use the dst non-alpha
+    dst = dst.extract_band(0, VImage::option()->set("n", dst.bands() - 1));
+
+    // the range of the mask and the image need to match .. one could be
+    // 16-bit, one 8-bit
+    double const dstMax = MaximumImageAlpha(dst.interpretation());
+    double const maskMax = MaximumImageAlpha(mask.interpretation());
+
+    // combine the new mask and the existing alpha ... there are
+    // many ways of doing this, mult is the simplest
+    mask = dstMax * ((mask / maskMax) * (dstAlpha / dstMax));
+
+    // append the mask to the image data ... the mask might be float now,
+    // we must cast the format down to match the image data
+    return dst.bandjoin(mask.cast(dst.format()));
+  }
+
+  /*
+   * Tint an image using the specified chroma, preserving the original image luminance
+   */
+  VImage Tint(VImage image, double const a, double const b) {
+    // Get original colourspace
+    VipsInterpretation typeBeforeTint = image.interpretation();
+    if (typeBeforeTint == VIPS_INTERPRETATION_RGB) {
+      typeBeforeTint = VIPS_INTERPRETATION_sRGB;
+    }
+    // Extract luminance
+    VImage luminance = image.colourspace(VIPS_INTERPRETATION_LAB)[0];
+    // Create the tinted version by combining the L from the original and the chroma from the tint
+    std::vector<double> chroma {a, b};
+    VImage tinted = luminance
+      .bandjoin(chroma)
+      .copy(VImage::option()->set("interpretation", VIPS_INTERPRETATION_LAB))
+      .colourspace(typeBeforeTint);
+    // Attach original alpha channel, if any
+    if (HasAlpha(image)) {
+      // Extract original alpha channel
+      VImage alpha = image[image.bands() - 1];
+      // Join alpha channel to normalised image
+      tinted = tinted.bandjoin(alpha);
+    }
+    return tinted;
+  }
+
   /*
    * Stretch luminance to cover full dynamic range.
    */
-  VImage Normalize(VImage image) {
+  VImage Normalise(VImage image) {
     // Get original colourspace
     VipsInterpretation typeBeforeNormalize = image.interpretation();
     if (typeBeforeNormalize == VIPS_INTERPRETATION_RGB) {
@@ -125,20 +245,18 @@ namespace sharp {
   VImage Gamma(VImage image, double const exponent) {
     if (HasAlpha(image)) {
       // Separate alpha channel
-      VImage imageWithoutAlpha = image.extract_band(0,
-        VImage::option()->set("n", image.bands() - 1));
       VImage alpha = image[image.bands() - 1];
-      return imageWithoutAlpha.gamma(VImage::option()->set("exponent", exponent)).bandjoin(alpha);
+      return RemoveAlpha(image).gamma(VImage::option()->set("exponent", exponent)).bandjoin(alpha);
     } else {
       return image.gamma(VImage::option()->set("exponent", exponent));
     }
   }
 
   /*
-   * Gaussian blur (use sigma <0 for fast blur)
+   * Gaussian blur. Use sigma of -1.0 for fast blur.
    */
   VImage Blur(VImage image, double const sigma) {
-    if (sigma < 0.0) {
+    if (sigma == -1.0) {
       // Fast, mild blur - averages neighbouring pixels
       VImage blur = VImage::new_matrixv(3, 3,
         1.0, 1.0, 1.0,
@@ -153,10 +271,49 @@ namespace sharp {
   }
 
   /*
-   * Sharpen flat and jagged areas. Use radius of -1 for fast sharpen.
+   * Convolution with a kernel.
    */
-  VImage Sharpen(VImage image, int const radius, double const flat, double const jagged) {
+  VImage Convolve(VImage image, int const width, int const height,
-    if (radius == -1) {
+    double const scale, double const offset,
+    std::unique_ptr<double[]> const &kernel_v
+  ) {
+    VImage kernel = VImage::new_from_memory(
+      kernel_v.get(),
+      width * height * sizeof(double),
+      width,
+      height,
+      1,
+      VIPS_FORMAT_DOUBLE);
+    kernel.set("scale", scale);
+    kernel.set("offset", offset);
+
+    return image.conv(kernel);
+  }
+
+  /*
+   * Recomb with a Matrix of the given bands/channel size.
+   * Eg. RGB will be a 3x3 matrix.
+   */
+  VImage Recomb(VImage image, std::unique_ptr<double[]> const &matrix) {
+    double *m = matrix.get();
+    return image
+      .colourspace(VIPS_INTERPRETATION_sRGB)
+      .recomb(image.bands() == 3
+        ? VImage::new_from_memory(
+          m, 9 * sizeof(double), 3, 3, 1, VIPS_FORMAT_DOUBLE
+        )
+        : VImage::new_matrixv(4, 4,
+          m[0], m[1], m[2], 0.0,
+          m[3], m[4], m[5], 0.0,
+          m[6], m[7], m[8], 0.0,
+          0.0, 0.0, 0.0, 1.0));
+  }
+
+  /*
+   * Sharpen flat and jagged areas. Use sigma of -1.0 for fast sharpen.
+   */
+  VImage Sharpen(VImage image, double const sigma, double const flat, double const jagged) {
+    if (sigma == -1.0) {
       // Fast, mild sharpen
       VImage sharpen = VImage::new_matrixv(3, 3,
         -1.0, -1.0, -1.0,
@@ -166,88 +323,67 @@ namespace sharp {
       return image.conv(sharpen);
     } else {
       // Slow, accurate sharpen in LAB colour space, with control over flat vs jagged areas
+      VipsInterpretation colourspaceBeforeSharpen = image.interpretation();
+      if (colourspaceBeforeSharpen == VIPS_INTERPRETATION_RGB) {
+        colourspaceBeforeSharpen = VIPS_INTERPRETATION_sRGB;
+      }
       return image.sharpen(
-        VImage::option()->set("radius", radius)->set("m1", flat)->set("m2", jagged)
+        VImage::option()->set("sigma", sigma)->set("m1", flat)->set("m2", jagged))
-      );
+        .colourspace(colourspaceBeforeSharpen);
     }
   }
 
+  VImage Threshold(VImage image, double const threshold, bool const thresholdGrayscale) {
+    if (!thresholdGrayscale) {
+      return image >= threshold;
+    }
+    return image.colourspace(VIPS_INTERPRETATION_B_W) >= threshold;
+  }
+
   /*
-    Calculate crop area based on image entropy
+    Perform boolean/bitwise operation on image color channels - results in one channel image
   */
-  std::tuple<int, int> EntropyCrop(VImage image, int const outWidth, int const outHeight) {
+  VImage Bandbool(VImage image, VipsOperationBoolean const boolean) {
-    int left = 0;
+    image = image.bandbool(boolean);
-    int top = 0;
+    return image.copy(VImage::option()->set("interpretation", VIPS_INTERPRETATION_B_W));
-    int const inWidth = image.width();
-    int const inHeight = image.height();
-    if (inWidth > outWidth) {
-      // Reduce width by repeated removing slices from edge with lowest entropy
-      int width = inWidth;
-      double leftEntropy = 0.0;
-      double rightEntropy = 0.0;
-      // Max width of each slice
-      int const maxSliceWidth = static_cast<int>(ceil((inWidth - outWidth) / 8.0));
-      while (width > outWidth) {
-        // Width of current slice
-        int const slice = std::min(width - outWidth, maxSliceWidth);
-        if (leftEntropy == 0.0) {
-          // Update entropy of left slice
-          leftEntropy = Entropy(image.extract_area(left, 0, slice, inHeight));
-        }
-        if (rightEntropy == 0.0) {
-          // Update entropy of right slice
-          rightEntropy = Entropy(image.extract_area(width - slice - 1, 0, slice, inHeight));
-        }
-        // Keep slice with highest entropy
-        if (leftEntropy >= rightEntropy) {
-          // Discard right slice
-          rightEntropy = 0.0;
-        } else {
-          // Discard left slice
-          leftEntropy = 0.0;
-          left = left + slice;
-        }
-        width = width - slice;
-      }
-    }
-    if (inHeight > outHeight) {
-      // Reduce height by repeated removing slices from edge with lowest entropy
-      int height = inHeight;
-      double topEntropy = 0.0;
-      double bottomEntropy = 0.0;
-      // Max height of each slice
-      int const maxSliceHeight = static_cast<int>(ceil((inHeight - outHeight) / 8.0));
-      while (height > outHeight) {
-        // Height of current slice
-        int const slice = std::min(height - outHeight, maxSliceHeight);
-        if (topEntropy == 0.0) {
-          // Update entropy of top slice
-          topEntropy = Entropy(image.extract_area(0, top, inWidth, slice));
-        }
-        if (bottomEntropy == 0.0) {
-          // Update entropy of bottom slice
-          bottomEntropy = Entropy(image.extract_area(0, height - slice - 1, inWidth, slice));
-        }
-        // Keep slice with highest entropy
-        if (topEntropy >= bottomEntropy) {
-          // Discard bottom slice
-          bottomEntropy = 0.0;
-        } else {
-          // Discard top slice
-          topEntropy = 0.0;
-          top = top + slice;
-        }
-        height = height - slice;
-      }
-    }
-    return std::make_tuple(left, top);
   }
 
   /*
-    Calculate the Shannon entropy for an image
+    Perform bitwise boolean operation between images
   */
-  double Entropy(VImage image) {
+  VImage Boolean(VImage image, VImage imageR, VipsOperationBoolean const boolean) {
-    return image.hist_find().hist_entropy();
+    return image.boolean(imageR, boolean);
   }
 
+  /*
+    Trim an image
+  */
+  VImage Trim(VImage image, double const threshold) {
+    // Top-left pixel provides the background colour
+    VImage background = image.extract_area(0, 0, 1, 1);
+    if (HasAlpha(background)) {
+      background = background.flatten();
+    }
+    int top, width, height;
+    int const left = image.find_trim(&top, &width, &height, VImage::option()
+      ->set("background", background(0, 0))
+      ->set("threshold", threshold));
+    if (width == 0 || height == 0) {
+      throw VError("Unexpected error while trimming. Try to lower the tolerance");
+    }
+    return image.extract_area(left, top, width, height);
+  }
+
+  /*
+   * Calculate (a * in + b)
+   */
+  VImage Linear(VImage image, double const a, double const b) {
+    if (HasAlpha(image)) {
+      // Separate alpha channel
+      VImage alpha = image[image.bands() - 1];
+      return RemoveAlpha(image).linear(a, b).bandjoin(alpha);
+    } else {
+      return image.linear(a, b);
+    }
+  }
 }  // namespace sharp

src/operations.h

@@ -1,6 +1,23 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #ifndef SRC_OPERATIONS_H_
 #define SRC_OPERATIONS_H_
 
+#include <algorithm>
+#include <functional>
+#include <memory>
 #include <tuple>
 #include <vips/vips8>
 
@@ -8,16 +25,46 @@ using vips::VImage;
 
 namespace sharp {
 
+  /*
+    Removes alpha channel, if any.
+  */
+  VImage RemoveAlpha(VImage image);
+
+  /*
+    Ensures alpha channel, if missing.
+  */
+  VImage EnsureAlpha(VImage image);
+
   /*
     Alpha composite src over dst with given gravity.
     Assumes alpha channels are already premultiplied and will be unpremultiplied after.
    */
   VImage Composite(VImage src, VImage dst, const int gravity);
 
+  /*
+    Composite overlayImage over image at given position
+   */
+  VImage Composite(VImage image, VImage overlayImage, int const x, int const y);
+
+  /*
+    Alpha composite overlayImage over image, assumes matching dimensions
+  */
+  VImage AlphaComposite(VImage image, VImage overlayImage);
+
+  /*
+    Cutout src over dst with given gravity.
+  */
+  VImage Cutout(VImage src, VImage dst, const int gravity);
+
+  /*
+   * Tint an image using the specified chroma, preserving the original image luminance
+   */
+  VImage Tint(VImage image, double const a, double const b);
+
   /*
    * Stretch luminance to cover full dynamic range.
    */
-  VImage Normalize(VImage image);
+  VImage Normalise(VImage image);
 
   /*
    * Gamma encoding/decoding
@@ -25,24 +72,51 @@ namespace sharp {
   VImage Gamma(VImage image, double const exponent);
 
   /*
-   * Gaussian blur. Use sigma of -1 for fast blur.
+   * Gaussian blur. Use sigma of -1.0 for fast blur.
    */
   VImage Blur(VImage image, double const sigma);
 
   /*
-   * Sharpen flat and jagged areas. Use radius of -1 for fast sharpen.
+   * Convolution with a kernel.
    */
-  VImage Sharpen(VImage image, int const radius, double const flat, double const jagged);
+  VImage Convolve(VImage image, int const width, int const height,
+    double const scale, double const offset, std::unique_ptr<double[]> const &kernel_v);
 
   /*
-    Calculate crop area based on image entropy
+   * Sharpen flat and jagged areas. Use sigma of -1.0 for fast sharpen.
-  */
+   */
-  std::tuple<int, int> EntropyCrop(VImage image, int const outWidth, int const outHeight);
+  VImage Sharpen(VImage image, double const sigma, double const flat, double const jagged);
 
   /*
-    Calculate the Shannon entropy for an image
+    Threshold an image
   */
-  double Entropy(VImage image);
+  VImage Threshold(VImage image, double const threshold, bool const thresholdColor);
+
+  /*
+    Perform boolean/bitwise operation on image color channels - results in one channel image
+  */
+  VImage Bandbool(VImage image, VipsOperationBoolean const boolean);
+
+  /*
+    Perform bitwise boolean operation between images
+  */
+  VImage Boolean(VImage image, VImage imageR, VipsOperationBoolean const boolean);
+
+  /*
+    Trim an image
+  */
+  VImage Trim(VImage image, double const threshold);
+
+  /*
+   * Linear adjustment (a * in + b)
+   */
+  VImage Linear(VImage image, double const a, double const b);
+
+  /*
+   * Recomb with a Matrix of the given bands/channel size.
+   * Eg. RGB will be a 3x3 matrix.
+   */
+  VImage Recomb(VImage image, std::unique_ptr<double[]> const &matrix);
 
 }  // namespace sharp
 

src/pipeline.h

@@ -1,9 +1,28 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #ifndef SRC_PIPELINE_H_
 #define SRC_PIPELINE_H_
 
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <nan.h>
 #include <vips/vips8>
 
-#include "nan.h"
+#include "./common.h"
 
 NAN_METHOD(pipeline);
 
@@ -16,23 +35,20 @@ enum class Canvas {
 };
 
 struct PipelineBaton {
-  std::string fileIn;
+  sharp::InputDescriptor *input;
-  char *bufferIn;
-  size_t bufferInLength;
   std::string iccProfilePath;
   int limitInputPixels;
-  int density;
-  int rawWidth;
-  int rawHeight;
-  int rawChannels;
   std::string formatOut;
   std::string fileOut;
   void *bufferOut;
   size_t bufferOutLength;
-  std::string overlayFileIn;
+  sharp::InputDescriptor *overlay;
-  char *overlayBufferIn;
-  size_t overlayBufferInLength;
   int overlayGravity;
+  int overlayXOffset;
+  int overlayYOffset;
+  bool overlayTile;
+  bool overlayCutout;
+  std::vector<sharp::InputDescriptor *> joinChannelIn;
   int topOffsetPre;
   int leftOffsetPre;
   int widthPre;
@@ -45,20 +61,39 @@ struct PipelineBaton {
   int height;
   int channels;
   Canvas canvas;
-  int crop;
+  int position;
-  std::string interpolator;
+  std::vector<double> resizeBackground;
-  double background[4];
+  bool hasCropOffset;
+  int cropOffsetLeft;
+  int cropOffsetTop;
+  bool premultiplied;
+  std::string kernel;
+  bool fastShrinkOnLoad;
+  double tintA;
+  double tintB;
   bool flatten;
+  std::vector<double> flattenBackground;
   bool negate;
   double blurSigma;
-  int sharpenRadius;
+  int medianSize;
+  double sharpenSigma;
   double sharpenFlat;
   double sharpenJagged;
   int threshold;
+  bool thresholdGrayscale;
+  double trimThreshold;
+  int trimOffsetLeft;
+  int trimOffsetTop;
+  double linearA;
+  double linearB;
   double gamma;
+  double gammaOut;
   bool greyscale;
-  bool normalize;
+  bool normalise;
+  bool useExifOrientation;
   int angle;
+  double rotationAngle;
+  std::vector<double> rotationBackground;
   bool rotateBeforePreExtract;
   bool flip;
   bool flop;
@@ -66,78 +101,159 @@ struct PipelineBaton {
   int extendBottom;
   int extendLeft;
   int extendRight;
-  bool progressive;
+  std::vector<double> extendBackground;
   bool withoutEnlargement;
   VipsAccess accessMethod;
-  int quality;
+  int jpegQuality;
-  int compressionLevel;
+  bool jpegProgressive;
-  bool withoutAdaptiveFiltering;
+  std::string jpegChromaSubsampling;
-  bool withoutChromaSubsampling;
+  bool jpegTrellisQuantisation;
-  bool trellisQuantisation;
+  int jpegQuantisationTable;
-  bool overshootDeringing;
+  bool jpegOvershootDeringing;
-  bool optimiseScans;
+  bool jpegOptimiseScans;
+  bool jpegOptimiseCoding;
+  bool pngProgressive;
+  int pngCompressionLevel;
+  bool pngAdaptiveFiltering;
+  bool pngPalette;
+  int pngQuality;
+  int pngColours;
+  double pngDither;
+  int webpQuality;
+  int webpAlphaQuality;
+  bool webpNearLossless;
+  bool webpLossless;
+  int tiffQuality;
+  VipsForeignTiffCompression tiffCompression;
+  VipsForeignTiffPredictor tiffPredictor;
+  bool tiffPyramid;
+  bool tiffSquash;
+  bool tiffTile;
+  int tiffTileHeight;
+  int tiffTileWidth;
+  double tiffXres;
+  double tiffYres;
   std::string err;
   bool withMetadata;
   int withMetadataOrientation;
+  std::unique_ptr<double[]> convKernel;
+  int convKernelWidth;
+  int convKernelHeight;
+  double convKernelScale;
+  double convKernelOffset;
+  sharp::InputDescriptor *boolean;
+  VipsOperationBoolean booleanOp;
+  VipsOperationBoolean bandBoolOp;
+  int extractChannel;
+  bool removeAlpha;
+  bool ensureAlpha;
+  VipsInterpretation colourspace;
   int tileSize;
   int tileOverlap;
   VipsForeignDzContainer tileContainer;
   VipsForeignDzLayout tileLayout;
+  std::string tileFormat;
+  int tileAngle;
+  VipsForeignDzDepth tileDepth;
+  std::unique_ptr<double[]> recombMatrix;
 
   PipelineBaton():
-    bufferInLength(0),
+    input(nullptr),
     limitInputPixels(0),
-    density(72),
-    rawWidth(0),
-    rawHeight(0),
-    rawChannels(0),
-    formatOut(""),
-    fileOut(""),
     bufferOutLength(0),
-    overlayBufferInLength(0),
+    overlay(nullptr),
     overlayGravity(0),
+    overlayXOffset(-1),
+    overlayYOffset(-1),
+    overlayTile(false),
+    overlayCutout(false),
     topOffsetPre(-1),
     topOffsetPost(-1),
     channels(0),
     canvas(Canvas::CROP),
-    crop(0),
+    position(0),
+    resizeBackground{ 0.0, 0.0, 0.0, 255.0 },
+    hasCropOffset(false),
+    cropOffsetLeft(0),
+    cropOffsetTop(0),
+    premultiplied(false),
+    tintA(128.0),
+    tintB(128.0),
     flatten(false),
+    flattenBackground{ 0.0, 0.0, 0.0 },
     negate(false),
     blurSigma(0.0),
-    sharpenRadius(0),
+    medianSize(0),
+    sharpenSigma(0.0),
     sharpenFlat(1.0),
     sharpenJagged(2.0),
     threshold(0),
+    thresholdGrayscale(true),
+    trimThreshold(0.0),
+    trimOffsetLeft(0),
+    trimOffsetTop(0),
+    linearA(1.0),
+    linearB(0.0),
     gamma(0.0),
     greyscale(false),
-    normalize(false),
+    normalise(false),
+    useExifOrientation(false),
     angle(0),
+    rotationAngle(0.0),
+    rotationBackground{ 0.0, 0.0, 0.0, 255.0 },
     flip(false),
     flop(false),
     extendTop(0),
     extendBottom(0),
     extendLeft(0),
     extendRight(0),
-    progressive(false),
+    extendBackground{ 0.0, 0.0, 0.0, 255.0 },
     withoutEnlargement(false),
-    quality(80),
+    jpegQuality(80),
-    compressionLevel(6),
+    jpegProgressive(false),
-    withoutAdaptiveFiltering(false),
+    jpegChromaSubsampling("4:2:0"),
-    withoutChromaSubsampling(false),
+    jpegTrellisQuantisation(false),
-    trellisQuantisation(false),
+    jpegQuantisationTable(0),
-    overshootDeringing(false),
+    jpegOvershootDeringing(false),
-    optimiseScans(false),
+    jpegOptimiseScans(false),
+    jpegOptimiseCoding(true),
+    pngProgressive(false),
+    pngCompressionLevel(9),
+    pngAdaptiveFiltering(false),
+    pngPalette(false),
+    pngQuality(100),
+    pngColours(256),
+    pngDither(1.0),
+    webpQuality(80),
+    tiffQuality(80),
+    tiffCompression(VIPS_FOREIGN_TIFF_COMPRESSION_JPEG),
+    tiffPredictor(VIPS_FOREIGN_TIFF_PREDICTOR_HORIZONTAL),
+    tiffPyramid(false),
+    tiffSquash(false),
+    tiffTile(false),
+    tiffTileHeight(256),
+    tiffTileWidth(256),
+    tiffXres(1.0),
+    tiffYres(1.0),
     withMetadata(false),
     withMetadataOrientation(-1),
+    convKernelWidth(0),
+    convKernelHeight(0),
+    convKernelScale(0.0),
+    convKernelOffset(0.0),
+    boolean(nullptr),
+    booleanOp(VIPS_OPERATION_BOOLEAN_LAST),
+    bandBoolOp(VIPS_OPERATION_BOOLEAN_LAST),
+    extractChannel(-1),
+    removeAlpha(false),
+    ensureAlpha(false),
+    colourspace(VIPS_INTERPRETATION_LAST),
     tileSize(256),
     tileOverlap(0),
     tileContainer(VIPS_FOREIGN_DZ_CONTAINER_FS),
-    tileLayout(VIPS_FOREIGN_DZ_LAYOUT_DZ) {
+    tileLayout(VIPS_FOREIGN_DZ_LAYOUT_DZ),
-      background[0] = 0.0;
+    tileAngle(0),
-      background[1] = 0.0;
+    tileDepth(VIPS_FOREIGN_DZ_DEPTH_LAST) {}
-      background[2] = 0.0;
-      background[3] = 255.0;
-    }
 };
 
 #endif  // SRC_PIPELINE_H_

src/sharp.cc

@@ -1,16 +1,33 @@
-#include <node.h>
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
-#include <vips/vips8>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
 
-#include "nan.h"
+#include <node.h>
+#include <nan.h>
+#include <vips/vips8>
 
 #include "common.h"
 #include "metadata.h"
 #include "pipeline.h"
 #include "utilities.h"
+#include "stats.h"
 
 NAN_MODULE_INIT(init) {
   vips_init("sharp");
 
+  g_log_set_handler("VIPS", static_cast<GLogLevelFlags>(G_LOG_LEVEL_WARNING),
+    static_cast<GLogFunc>(sharp::VipsWarningCallback), nullptr);
+
   // Methods available to JavaScript
   Nan::Set(target, Nan::New("metadata").ToLocalChecked(),
     Nan::GetFunction(Nan::New<v8::FunctionTemplate>(metadata)).ToLocalChecked());
@@ -30,6 +47,8 @@ NAN_MODULE_INIT(init) {
     Nan::GetFunction(Nan::New<v8::FunctionTemplate>(format)).ToLocalChecked());
   Nan::Set(target, Nan::New("_maxColourDistance").ToLocalChecked(),
     Nan::GetFunction(Nan::New<v8::FunctionTemplate>(_maxColourDistance)).ToLocalChecked());
+  Nan::Set(target, Nan::New("stats").ToLocalChecked(),
+    Nan::GetFunction(Nan::New<v8::FunctionTemplate>(stats)).ToLocalChecked());
 }
 
 NODE_MODULE(sharp, init)

src/stats.cc

@@ -0,0 +1,192 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <numeric>
+#include <vector>
+#include <iostream>
+
+#include <node.h>
+#include <nan.h>
+#include <vips/vips8>
+
+#include "common.h"
+#include "stats.h"
+
+class StatsWorker : public Nan::AsyncWorker {
+ public:
+  StatsWorker(
+    Nan::Callback *callback, StatsBaton *baton, Nan::Callback *debuglog,
+    std::vector<v8::Local<v8::Object>> const buffersToPersist) :
+    Nan::AsyncWorker(callback, "sharp:StatsWorker"),
+    baton(baton), debuglog(debuglog),
+    buffersToPersist(buffersToPersist) {
+    // Protect Buffer objects from GC, keyed on index
+    std::accumulate(buffersToPersist.begin(), buffersToPersist.end(), 0,
+      [this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
+        SaveToPersistent(index, buffer);
+        return index + 1;
+      });
+  }
+  ~StatsWorker() {}
+
+  const int STAT_MIN_INDEX = 0;
+  const int STAT_MAX_INDEX = 1;
+  const int STAT_SUM_INDEX = 2;
+  const int STAT_SQ_SUM_INDEX = 3;
+  const int STAT_MEAN_INDEX = 4;
+  const int STAT_STDEV_INDEX = 5;
+  const int STAT_MINX_INDEX = 6;
+  const int STAT_MINY_INDEX = 7;
+  const int STAT_MAXX_INDEX = 8;
+  const int STAT_MAXY_INDEX = 9;
+
+  void Execute() {
+    // Decrement queued task counter
+    g_atomic_int_dec_and_test(&sharp::counterQueue);
+    using Nan::New;
+    using Nan::Set;
+    using sharp::MaximumImageAlpha;
+
+    vips::VImage image;
+    sharp::ImageType imageType = sharp::ImageType::UNKNOWN;
+
+    try {
+      std::tie(image, imageType) = OpenInput(baton->input, baton->accessMethod);
+    } catch (vips::VError const &err) {
+      (baton->err).append(err.what());
+    }
+    if (imageType != sharp::ImageType::UNKNOWN) {
+      try {
+        vips::VImage stats = image.stats();
+        int const bands = image.bands();
+        for (int b = 1; b <= bands; b++) {
+          ChannelStats cStats(static_cast<int>(stats.getpoint(STAT_MIN_INDEX, b).front()),
+                              static_cast<int>(stats.getpoint(STAT_MAX_INDEX, b).front()),
+                              stats.getpoint(STAT_SUM_INDEX, b).front(), stats.getpoint(STAT_SQ_SUM_INDEX, b).front(),
+                              stats.getpoint(STAT_MEAN_INDEX, b).front(), stats.getpoint(STAT_STDEV_INDEX, b).front(),
+                              static_cast<int>(stats.getpoint(STAT_MINX_INDEX, b).front()),
+                              static_cast<int>(stats.getpoint(STAT_MINY_INDEX, b).front()),
+                              static_cast<int>(stats.getpoint(STAT_MAXX_INDEX, b).front()),
+                              static_cast<int>(stats.getpoint(STAT_MAXY_INDEX, b).front()));
+          baton->channelStats.push_back(cStats);
+        }
+        // Image is not opaque when alpha layer is present and contains a non-mamixa value
+        if (sharp::HasAlpha(image)) {
+          double const minAlpha = static_cast<double>(stats.getpoint(STAT_MIN_INDEX, bands).front());
+          if (minAlpha != MaximumImageAlpha(image.interpretation())) {
+            baton->isOpaque = false;
+          }
+        }
+        // Estimate entropy via histogram of greyscale value frequency
+        baton->entropy = std::abs(image.colourspace(VIPS_INTERPRETATION_B_W)[0].hist_find().hist_entropy());
+      } catch (vips::VError const &err) {
+        (baton->err).append(err.what());
+      }
+    }
+
+    // Clean up
+    vips_error_clear();
+    vips_thread_shutdown();
+  }
+
+  void HandleOKCallback() {
+    using Nan::New;
+    using Nan::Set;
+    Nan::HandleScope();
+
+    v8::Local<v8::Value> argv[2] = { Nan::Null(), Nan::Null() };
+    if (!baton->err.empty()) {
+      argv[0] = Nan::Error(baton->err.data());
+    } else {
+      // Stats Object
+      v8::Local<v8::Object> info = New<v8::Object>();
+      v8::Local<v8::Array> channels = New<v8::Array>();
+
+      std::vector<ChannelStats>::iterator it;
+      int i = 0;
+      for (it=baton->channelStats.begin() ; it < baton->channelStats.end(); it++, i++) {
+        v8::Local<v8::Object> channelStat = New<v8::Object>();
+        Set(channelStat, New("min").ToLocalChecked(), New<v8::Number>(it->min));
+        Set(channelStat, New("max").ToLocalChecked(), New<v8::Number>(it->max));
+        Set(channelStat, New("sum").ToLocalChecked(), New<v8::Number>(it->sum));
+        Set(channelStat, New("squaresSum").ToLocalChecked(), New<v8::Number>(it->squaresSum));
+        Set(channelStat, New("mean").ToLocalChecked(), New<v8::Number>(it->mean));
+        Set(channelStat, New("stdev").ToLocalChecked(), New<v8::Number>(it->stdev));
+        Set(channelStat, New("minX").ToLocalChecked(), New<v8::Number>(it->minX));
+        Set(channelStat, New("minY").ToLocalChecked(), New<v8::Number>(it->minY));
+        Set(channelStat, New("maxX").ToLocalChecked(), New<v8::Number>(it->maxX));
+        Set(channelStat, New("maxY").ToLocalChecked(), New<v8::Number>(it->maxY));
+        channels->Set(i, channelStat);
+      }
+
+      Set(info, New("channels").ToLocalChecked(), channels);
+      Set(info, New("isOpaque").ToLocalChecked(), New<v8::Boolean>(baton->isOpaque));
+      Set(info, New("entropy").ToLocalChecked(), New<v8::Number>(baton->entropy));
+      argv[1] = info;
+    }
+
+    // Dispose of Persistent wrapper around input Buffers so they can be garbage collected
+    std::accumulate(buffersToPersist.begin(), buffersToPersist.end(), 0,
+      [this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
+        GetFromPersistent(index);
+        return index + 1;
+      });
+    delete baton->input;
+    delete baton;
+
+    // Handle warnings
+    std::string warning = sharp::VipsWarningPop();
+    while (!warning.empty()) {
+      v8::Local<v8::Value> message[1] = { New(warning).ToLocalChecked() };
+      debuglog->Call(1, message, async_resource);
+      warning = sharp::VipsWarningPop();
+    }
+
+    // Return to JavaScript
+    callback->Call(2, argv, async_resource);
+  }
+
+ private:
+  StatsBaton* baton;
+  Nan::Callback *debuglog;
+  std::vector<v8::Local<v8::Object>> buffersToPersist;
+};
+
+/*
+  stats(options, callback)
+*/
+NAN_METHOD(stats) {
+  using sharp::AttrTo;
+
+  // Input Buffers must not undergo GC compaction during processing
+  std::vector<v8::Local<v8::Object>> buffersToPersist;
+
+  // V8 objects are converted to non-V8 types held in the baton struct
+  StatsBaton *baton = new StatsBaton;
+  v8::Local<v8::Object> options = info[0].As<v8::Object>();
+
+  // Input
+  baton->input = sharp::CreateInputDescriptor(sharp::AttrAs<v8::Object>(options, "input"), buffersToPersist);
+  baton->accessMethod = AttrTo<bool>(options, "sequentialRead") ? VIPS_ACCESS_SEQUENTIAL : VIPS_ACCESS_RANDOM;
+
+  // Function to notify of libvips warnings
+  Nan::Callback *debuglog = new Nan::Callback(sharp::AttrAs<v8::Function>(options, "debuglog"));
+
+  // Join queue for worker thread
+  Nan::Callback *callback = new Nan::Callback(info[1].As<v8::Function>());
+  Nan::AsyncQueueWorker(new StatsWorker(callback, baton, debuglog, buffersToPersist));
+
+  // Increment queued task counter
+  g_atomic_int_inc(&sharp::counterQueue);
+}

src/stats.h

@@ -0,0 +1,67 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SRC_STATS_H_
+#define SRC_STATS_H_
+
+#include <string>
+#include <nan.h>
+
+#include "./common.h"
+
+struct ChannelStats {
+  // stats per channel
+  int min;
+  int max;
+  double sum;
+  double squaresSum;
+  double mean;
+  double stdev;
+  int minX;
+  int minY;
+  int maxX;
+  int maxY;
+
+  ChannelStats():
+    min(0), max(0), sum(0), squaresSum(0), mean(0), stdev(0)
+    , minX(0), minY(0), maxX(0), maxY(0) {}
+
+    ChannelStats(int minVal, int maxVal, double sumVal, double squaresSumVal,
+                  double meanVal, double stdevVal, int minXVal, int minYVal, int maxXVal, int maxYVal):
+    min(minVal), max(maxVal), sum(sumVal), squaresSum(squaresSumVal),
+    mean(meanVal), stdev(stdevVal), minX(minXVal), minY(minYVal), maxX(maxXVal), maxY(maxYVal) {}
+};
+
+struct StatsBaton {
+  // Input
+  sharp::InputDescriptor *input;
+  VipsAccess accessMethod;
+
+  // Output
+  std::vector<ChannelStats> channelStats;
+  bool isOpaque;
+  double entropy;
+
+  std::string err;
+
+  StatsBaton():
+    input(nullptr),
+    isOpaque(true),
+    entropy(0.0)
+    {}
+};
+
+NAN_METHOD(stats);
+
+#endif  // SRC_STATS_H_

src/utilities.cc

@@ -1,10 +1,25 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #include <cmath>
+#include <string>
+
 #include <node.h>
+#include <nan.h>
 #include <vips/vips8>
 #include <vips/vector.h>
 
-#include "nan.h"
-
 #include "common.h"
 #include "operations.h"
 #include "utilities.h"
@@ -45,14 +60,11 @@ NAN_METHOD(cache) {
   // Get memory stats
   Local<Object> memory = New<Object>();
   Set(memory, New("current").ToLocalChecked(),
-    New<Integer>(static_cast<int>(round(vips_tracked_get_mem() / 1048576)))
+    New<Integer>(static_cast<int>(round(vips_tracked_get_mem() / 1048576))));
-  );
   Set(memory, New("high").ToLocalChecked(),
-    New<Integer>(static_cast<int>(round(vips_tracked_get_mem_highwater() / 1048576)))
+    New<Integer>(static_cast<int>(round(vips_tracked_get_mem_highwater() / 1048576))));
-  );
   Set(memory, New("max").ToLocalChecked(),
-    New<Integer>(static_cast<int>(round(vips_cache_get_max_mem() / 1048576)))
+    New<Integer>(static_cast<int>(round(vips_cache_get_max_mem() / 1048576))));
-  );
   // Get file stats
   Local<Object> files = New<Object>();
   Set(files, New("current").ToLocalChecked(), New<Integer>(vips_tracked_get_files()));
@@ -138,7 +150,9 @@ NAN_METHOD(format) {
 
   // Which load/save operations are available for each compressed format?
   Local<Object> format = New<Object>();
-  for (std::string f : {"jpeg", "png", "webp", "tiff", "magick", "openslide", "dz"}) {
+  for (std::string f : {
+    "jpeg", "png", "webp", "tiff", "magick", "openslide", "dz", "ppm", "fits", "gif", "svg", "pdf", "v"
+  }) {
     // Input
     Local<Boolean> hasInputFile =
       New<Boolean>(vips_type_find("VipsOperation", (f + "load").c_str()));
@@ -245,7 +259,7 @@ NAN_METHOD(_maxColourDistance) {
     }
     // Calculate colour distance
     maxColourDistance = image1.dE00(image2).max();
-  } catch (VError err) {
+  } catch (VError const &err) {
     return ThrowError(err.what());
   }
 

src/utilities.h

@@ -1,7 +1,21 @@
+// Copyright 2013, 2014, 2015, 2016, 2017, 2018, 2019 Lovell Fuller and contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 #ifndef SRC_UTILITIES_H_
 #define SRC_UTILITIES_H_
 
-#include "nan.h"
+#include <nan.h>
 
 NAN_METHOD(cache);
 NAN_METHOD(concurrency);

test/bench/package.json

@@ -5,20 +5,20 @@
   "author": "Lovell Fuller <npm@lovell.info>",
   "description": "Benchmark and performance tests for sharp",
   "scripts": {
-    "test": "VIPS_WARNING=0 node perf && node random && node parallel"
+    "test": "node perf && node random && node parallel"
   },
   "devDependencies": {
-    "async": "^1.5.2",
+    "async": "^2.6.1",
-    "benchmark": "^2.1.0",
+    "benchmark": "^2.1.4",
-    "gm": "^1.21.0",
+    "gm": "^1.23.1",
     "imagemagick": "^0.1.3",
-    "imagemagick-native": "^1.9.2",
+    "imagemagick-native": "^1.9.3",
-    "jimp": "^0.2.20",
+    "jimp": "^0.5.3",
-    "lwip": "^0.0.8",
+    "mapnik": "^4.0.1",
-    "semver": "^5.1.0"
+    "semver": "^5.5.1"
   },
   "license": "Apache-2.0",
   "engines": {
-    "node": ">=0.10"
+    "node": ">=6"
   }
 }

test/bench/parallel.js

@@ -2,43 +2,44 @@
 
 process.env.UV_THREADPOOL_SIZE = 64;
 
-var assert = require('assert');
+const assert = require('assert');
-var async = require('async');
+const async = require('async');
 
-var sharp = require('../../index');
+const sharp = require('../../');
-var fixtures = require('../fixtures');
+const fixtures = require('../fixtures');
 
-var width = 720;
+const width = 720;
-var height = 480;
+const height = 480;
 
 sharp.concurrency(1);
 sharp.simd(true);
 
-var timer = setInterval(function() {
+const timer = setInterval(function () {
   console.dir(sharp.counters());
 }, 100);
 
-async.mapSeries([1, 1, 2, 4, 8, 16, 32, 64], function(parallelism, next) {
+async.mapSeries([1, 1, 2, 4, 8, 16, 32, 64], function (parallelism, next) {
-  var start = new Date().getTime();
+  const start = new Date().getTime();
   async.times(parallelism,
-    function(id, callback) {
+    function (id, callback) {
-      /*jslint unused: false */
+      /* jslint unused: false */
-      sharp(fixtures.inputJpg).resize(width, height).toBuffer(function(err, buffer) {
+      sharp(fixtures.inputJpg).resize(width, height).toBuffer(function (err, buffer) {
         buffer = null;
         callback(err, new Date().getTime() - start);
       });
     },
-    function(err, ids) {
+    function (err, ids) {
       assert(!err);
       assert(ids.length === parallelism);
-      var mean = ids.reduce(function(a, b) {
+      ids.sort();
+      const mean = ids.reduce(function (a, b) {
         return a + b;
       }) / ids.length;
       console.log(parallelism + ' parallel calls: fastest=' + ids[0] + 'ms slowest=' + ids[ids.length - 1] + 'ms mean=' + mean + 'ms');
       next();
     }
   );
-}, function() {
+}, function () {
   clearInterval(timer);
   console.dir(sharp.counters());
 });

test/bench/random.js

@@ -1,28 +1,26 @@
 'use strict';
 
-var imagemagick = require('imagemagick');
+const imagemagick = require('imagemagick');
-var gm = require('gm');
+const gm = require('gm');
-var assert = require('assert');
+const assert = require('assert');
-var Benchmark = require('benchmark');
+const Benchmark = require('benchmark');
 
-var sharp = require('../../index');
+const sharp = require('../../');
-var fixtures = require('../fixtures');
+const fixtures = require('../fixtures');
 
+sharp.cache(false);
 sharp.simd(true);
 
-var min = 320;
+const min = 320;
-var max = 960;
+const max = 960;
 
-// Nearest equivalent to bilinear
+const randomDimension = function () {
-var magickFilter = 'Triangle';
+  return Math.ceil((Math.random() * (max - min)) + min);
-
-var randomDimension = function() {
-  return Math.ceil(Math.random() * (max - min) + min);
 };
 
 new Benchmark.Suite('random').add('imagemagick', {
   defer: true,
-  fn: function(deferred) {
+  fn: function (deferred) {
     imagemagick.resize({
       srcPath: fixtures.inputJpg,
       dstPath: fixtures.outputJpg,
@@ -30,8 +28,8 @@ new Benchmark.Suite('random').add('imagemagick', {
       width: randomDimension(),
       height: randomDimension(),
       format: 'jpg',
-      filter: magickFilter
+      filter: 'Lanczos'
-    }, function(err) {
+    }, function (err) {
       if (err) {
         throw err;
       } else {
@@ -41,10 +39,10 @@ new Benchmark.Suite('random').add('imagemagick', {
   }
 }).add('gm', {
   defer: true,
-  fn: function(deferred) {
+  fn: function (deferred) {
     gm(fixtures.inputJpg)
       .resize(randomDimension(), randomDimension())
-      .filter(magickFilter)
+      .filter('Lanczos')
       .quality(80)
       .toBuffer(function (err, buffer) {
         if (err) {
@@ -57,20 +55,21 @@ new Benchmark.Suite('random').add('imagemagick', {
   }
 }).add('sharp', {
   defer: true,
-  fn: function(deferred) {
+  fn: function (deferred) {
-    sharp(fixtures.inputJpg).resize(randomDimension(), randomDimension()).toBuffer(function(err, buffer) {
+    sharp(fixtures.inputJpg)
-      if (err) {
+      .resize(randomDimension(), randomDimension())
-        throw err;
+      .toBuffer(function (err, buffer) {
-      } else {
+        if (err) {
-        assert.notStrictEqual(null, buffer);
+          throw err;
-        deferred.resolve();
+        } else {
-      }
+          assert.notStrictEqual(null, buffer);
-    });
+          deferred.resolve();
+        }
+      });
   }
-}).on('cycle', function(event) {
+}).on('cycle', function (event) {
   console.log(String(event.target));
-}).on('complete', function() {
+}).on('complete', function () {
-  var winner = this.filter('fastest').map('name');
+  const winner = this.filter('fastest').map('name');
   assert.strictEqual('sharp', String(winner), 'sharp was slower than ' + winner);
-  console.dir(sharp.cache());
 }).run();

test/coverage/report.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+CPPFLAGS="--coverage" LDFLAGS="--coverage" npm rebuild
+npm test
+geninfo --no-external --base-directory src --output-file coverage/sharp.info build/Release/obj.target/sharp/src
+genhtml --title sharp --demangle-cpp --output-directory coverage/sharp coverage/*.info