Release v0.20.7

Alpha for colour is between 0-1, not 0-255.

.gitattributes

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

.gitignore

@@ -1,6 +1,6 @@
 build
 node_modules
-coverage
+/coverage
 test/bench/node_modules
 test/fixtures/output*
 test/leak/libvips.supp
@@ -9,8 +9,7 @@ test/saliency/Image*
 test/saliency/[Uu]serData*
 !test/saliency/userData.js
 vendor
-packaging/libvips*
-packaging/*.log
-!packaging/build
+.gitattributes
 .DS_Store
 .nyc_output
+package-lock.json

.npmignore

@@ -2,13 +2,14 @@ build
 node_modules
 coverage
 .editorconfig
+.gitattributes
 .gitignore
 test
 .travis.yml
 appveyor.yml
-circle.yml
 mkdocs.yml
+docs/css/
 vendor
-packaging
-preinstall.sh
+.prebuildrc
 .nyc_output
+CONTRIBUTING.md

.prebuildrc

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

.travis.yml

@@ -13,15 +13,22 @@ matrix:
       dist: trusty
       sudo: false
       node_js: "8"
+    - os: linux
+      dist: trusty
+      sudo: false
+      node_js: "10"
     - os: osx
-      osx_image: xcode8
+      osx_image: xcode8.3
       node_js: "4"
     - os: osx
-      osx_image: xcode8
+      osx_image: xcode8.3
       node_js: "6"
     - os: osx
-      osx_image: xcode8
+      osx_image: xcode8.3
       node_js: "8"
+    - os: osx
+      osx_image: xcode8.3
+      node_js: "10"
 after_success:
   - npm install coveralls
   - cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js

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://jcupitt.github.io/libvips/API/current/) the feature you need.
 
 ## Submit a Pull Request to fix a bug
 
@@ -41,8 +41,8 @@ Any change that modifies the existing public API should be added to the relevant
 
 | Release | WIP branch |
 | ------: | :--------- |
-| v0.18.0 | ridge      |
-| v0.19.0 | suit       |
+| v0.21.0 | teeth      |
+| v0.22.0 | uptake     |
 
 Please squash your changes into a single commit using a command like `git rebase -i upstream/<wip-branch>`.
 
@@ -89,15 +89,6 @@ 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

README.md

@@ -4,6 +4,10 @@
 npm install sharp
 ```
 
+```sh
+yarn add sharp
+```
+
 The typical use case for this high speed Node.js module
 is to convert large images in common formats to
 smaller, web-friendly JPEG, PNG and WebP images of varying dimensions.
@@ -17,13 +21,14 @@ 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.
 
-OS X, Windows (x64), Linux (x64, ARM) systems do not require
-the installation of any external runtime dependencies.
+Most modern 64-bit OS X, Windows and Linux (glibc) systems running
+Node versions 4, 6, 8 and 10
+do not require any additional install or runtime dependencies.
 
 ## Examples
 
 ```javascript
-import sharp from 'sharp';
+const sharp = require('sharp');
 ```
 
 ```javascript
@@ -33,8 +38,6 @@ sharp(inputBuffer)
   // A Promises/A+ promise is returned when callback is not provided.
 ```
 
-
-
 ```javascript
 sharp('input.jpg')
   .rotate()
@@ -45,7 +48,7 @@ sharp('input.jpg')
 ```
 
 ```javascript
-const roundedCorners = new Buffer(
+const roundedCorners = Buffer.from(
   '<svg><rect x="0" y="0" width="200" height="200" rx="50" ry="50"/></svg>'
 );
 
@@ -64,11 +67,11 @@ readableStream
 
 ### Documentation
 
-Visit [sharp.dimens.io](http://sharp.dimens.io/) for complete
-[installation instructions](http://sharp.dimens.io/page/install),
-[API documentation](http://sharp.dimens.io/page/api),
-[benchmark tests](http://sharp.dimens.io/page/performance) and
-[changelog](http://sharp.dimens.io/page/changelog).
+Visit [sharp.pixelplumbing.com](http://sharp.pixelplumbing.com/) for complete
+[installation instructions](http://sharp.pixelplumbing.com/page/install),
+[API documentation](http://sharp.pixelplumbing.com/page/api),
+[benchmark tests](http://sharp.pixelplumbing.com/page/performance) and
+[changelog](http://sharp.pixelplumbing.com/page/changelog).
 
 ### Contributing
 
@@ -77,7 +80,7 @@ covers reporting bugs, requesting features and submitting code changes.
 
 ### Licence
 
-Copyright 2013, 2014, 2015, 2016, 2017 Lovell Fuller and contributors.
+Copyright 2013, 2014, 2015, 2016, 2017, 2018 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.

appveyor.yml

@@ -6,10 +6,11 @@ environment:
   matrix:
   - nodejs_version: "4"
   - nodejs_version: "6"
-  - nodejs_version: "7"
+  - nodejs_version: "8"
+  - nodejs_version: "10"
 install:
   - ps: Install-Product node $env:nodejs_version x64
-  - npm install -g npm@latest
+  - npm install -g npm@5
   - npm install
 test_script:
   - npm test

binding.gyp

@@ -5,9 +5,6 @@
       ['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',
           '_ALLOW_KEYWORD_MACROS'
@@ -49,43 +46,22 @@
     '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?
-          'use_global_vips': '<!(GLOBAL_VIPS_VERSION="<(global_vips_version)" node -e "require(\'./binding\').use_global_vips()")'
+          'pkg_config_path': '<!(node -e "console.log(require(\'./lib/libvips\').pkgConfigPath())")',
+          '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',
@@ -95,7 +71,7 @@
       '<!(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': [
@@ -112,7 +88,7 @@
           }]
         ]
       }, {
-        # Attempt to download pre-built libvips and install locally within node_modules
+        # Use pre-built libvips stored locally within node_modules
         'include_dirs': [
           'vendor/include',
           'vendor/include/glib-2.0',
@@ -130,9 +106,6 @@
             ]
           }],
           ['OS == "mac"', {
-            'variables': {
-              'download_vips': '<!(node -e "require(\'./binding\').download_vips()")'
-            },
             'libraries': [
               '../vendor/lib/libvips-cpp.42.dylib',
               '../vendor/lib/libvips.42.dylib',
@@ -143,9 +116,6 @@
             ]
           }],
           ['OS == "linux"', {
-            'variables': {
-              'download_vips': '<!(node -e "require(\'./binding\').download_vips()")'
-            },
             'defines': [
               '_GLIBCXX_USE_CXX11_ABI=0'
             ],
@@ -218,61 +188,5 @@
         ]
       }
     },
-  }, {
-    'target_name': 'win_copy_dlls',
-    'type': 'none',
-    'dependencies': [
-      'sharp'
-    ],
-    'conditions': [
-      ['OS == "win"', {
-        # Windows lacks support for rpath
-        'copies': [{
-          'destination': 'build/Release',
-          'files': [
-            'vendor/lib/GNU.Gettext.dll',
-            'vendor/lib/libasprintf-0.dll',
-            'vendor/lib/libcairo-2.dll',
-            'vendor/lib/libcairo-gobject-2.dll',
-            'vendor/lib/libcairo-script-interpreter-2.dll',
-            'vendor/lib/libcharset-1.dll',
-            'vendor/lib/libcroco-0.6-3.dll',
-            'vendor/lib/libexif-12.dll',
-            'vendor/lib/libexpat-1.dll',
-            'vendor/lib/libffi-6.dll',
-            'vendor/lib/libfftw3-3.dll',
-            'vendor/lib/libfontconfig-1.dll',
-            'vendor/lib/libfreetype-6.dll',
-            'vendor/lib/libgcc_s_seh-1.dll',
-            'vendor/lib/libgdk_pixbuf-2.0-0.dll',
-            'vendor/lib/libgif-7.dll',
-            'vendor/lib/libgio-2.0-0.dll',
-            'vendor/lib/libglib-2.0-0.dll',
-            'vendor/lib/libgmodule-2.0-0.dll',
-            'vendor/lib/libgobject-2.0-0.dll',
-            'vendor/lib/libgsf-1-114.dll',
-            'vendor/lib/libgthread-2.0-0.dll',
-            'vendor/lib/libiconv-2.dll',
-            'vendor/lib/libintl-8.dll',
-            'vendor/lib/libjpeg-62.dll',
-            'vendor/lib/liblcms2-2.dll',
-            'vendor/lib/libpango-1.0-0.dll',
-            'vendor/lib/libpangocairo-1.0-0.dll',
-            'vendor/lib/libpangowin32-1.0-0.dll',
-            'vendor/lib/libpixman-1-0.dll',
-            'vendor/lib/libpng16-16.dll',
-            'vendor/lib/libquadmath-0.dll',
-            'vendor/lib/librsvg-2-2.dll',
-            'vendor/lib/libssp-0.dll',
-            'vendor/lib/libstdc++-6.dll',
-            'vendor/lib/libtiff-5.dll',
-            'vendor/lib/libvips-42.dll',
-            'vendor/lib/libwebp-7.dll',
-            'vendor/lib/libxml2-2.dll',
-            'vendor/lib/zlib1.dll'
-          ]
-        }]
-      }]
-    ]
   }]
 }

binding.js

@@ -1,129 +0,0 @@
-'use strict';
-
-const fs = require('fs');
-const os = require('os');
-const path = require('path');
-
-const caw = require('caw');
-const simpleGet = require('simple-get');
-const semver = require('semver');
-const tar = require('tar');
-const detectLibc = require('detect-libc');
-
-const distBaseUrl = process.env.SHARP_DIST_BASE_URL || 'https://dl.bintray.com/lovell/sharp/';
-
-// Use NPM-provided environment variable where available, falling back to require-based method for Electron
-const minimumLibvipsVersion = process.env.npm_package_config_libvips || require('./package.json').config.libvips;
-
-const platform = process.env.npm_config_platform || process.platform;
-
-const arch = process.env.npm_config_arch || process.arch;
-
-// -- Helpers
-
-// Does this file exist?
-const isFile = function (file) {
-  try {
-    return fs.statSync(file).isFile();
-  } catch (err) {}
-};
-
-const unpack = function (tarPath, done) {
-  const vendorPath = path.join(__dirname, 'vendor');
-  fs.mkdirSync(vendorPath);
-  tar
-    .extract({
-      file: tarPath,
-      cwd: vendorPath,
-      strict: true
-    })
-    .then(done)
-    .catch(error);
-};
-
-const platformId = function () {
-  const platformId = [platform];
-  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('-');
-};
-
-// Error
-const 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?
-  const vipsHeaderPath = path.join(__dirname, 'vendor', 'include', 'vips', 'vips.h');
-  if (!isFile(vipsHeaderPath)) {
-    // Ensure Intel 64-bit or ARM
-    if (arch === 'ia32') {
-      error('Intel Architecture 32-bit systems require manual installation of libvips - please see http://sharp.dimens.io/page/install');
-    }
-    // Ensure glibc Linux
-    if (detectLibc.isNonGlibcLinux) {
-      error(`Use with ${detectLibc.family} libc requires manual installation of libvips - please see http://sharp.dimens.io/page/install`);
-    }
-    // Ensure glibc >= 2.13
-    if (detectLibc.family === detectLibc.GLIBC && detectLibc.version && semver.lt(`${detectLibc.version}.0`, '2.13.0')) {
-      error(`Use with glibc version ${detectLibc.version} requires manual installation of libvips - please see http://sharp.dimens.io/page/install`);
-    }
-    // Arch/platform-specific .tar.gz
-    const tarFilename = ['libvips', minimumLibvipsVersion, platformId()].join('-') + '.tar.gz';
-    const tarPathLocal = path.join(__dirname, 'packaging', tarFilename);
-    if (isFile(tarPathLocal)) {
-      unpack(tarPathLocal);
-    } else {
-      // Download to per-process temporary file
-      const tarPathTemp = path.join(os.tmpdir(), process.pid + '-' + tarFilename);
-      const tmpFile = fs.createWriteStream(tarPathTemp).on('finish', function () {
-        unpack(tarPathTemp, function () {
-          // Attempt to remove temporary file
-          try {
-            fs.unlinkSync(tarPathTemp);
-          } catch (err) {}
-        });
-      });
-      const url = distBaseUrl + tarFilename;
-      const simpleGetOpt = {
-        url: url,
-        agent: caw(null, {
-          protocol: 'https'
-        })
-      };
-      simpleGet(simpleGetOpt, function (err, response) {
-        if (err) {
-          error('Download of ' + url + ' failed: ' + err.message);
-        }
-        if (response.statusCode !== 200) {
-          error(url + ' status code ' + response.statusCode);
-        }
-        response.pipe(tmpFile);
-      });
-    }
-  }
-};
-
-module.exports.use_global_vips = function () {
-  const globalVipsVersion = process.env.GLOBAL_VIPS_VERSION;
-  if (globalVipsVersion) {
-    const useGlobalVips = semver.gte(
-      globalVipsVersion,
-      minimumLibvipsVersion
-    );
-    process.stdout.write(useGlobalVips ? 'true' : 'false');
-  } else {
-    process.stdout.write('false');
-  }
-};

circle.yml

@@ -1,8 +0,0 @@
-machine:
-  node:
-    version: v4.8.4
-  services:
-    - docker
-test:
-  override:
-    - ./packaging/test-linux-x64.sh

docs/api-channel.md

@@ -1,20 +1,30 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
+## removeAlpha
 
--   [extractChannel](#extractchannel)
--   [joinChannel](#joinchannel)
--   [bandbool](#bandbool)
+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** 
 
 ## extractChannel
 
 Extract a single channel from a multi-channel image.
 
-**Parameters**
+### Parameters
 
--   `channel` **([Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number) \| [String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String))** zero-indexed band number to extract, or `red`, `green` or `blue` as alternative to `0`, `1` or `2` respectively.
+-   `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**
+### Examples
 
 ```javascript
 sharp(input)
@@ -25,7 +35,7 @@ sharp(input)
    });
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid channel
+-   Throws **[Error][3]** Invalid channel
 
 Returns **Sharp** 
 
@@ -42,13 +52,13 @@ Channel ordering follows vips convention:
 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**
+### Parameters
 
--   `images` **([Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)&lt;([String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) \| [Buffer](https://nodejs.org/api/buffer.html))> | [String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) \| [Buffer](https://nodejs.org/api/buffer.html))** one or more images (file paths, Buffers).
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** image options, see `sharp()` constructor.
+-   `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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][3]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -56,11 +66,11 @@ Returns **Sharp**
 
 Perform a bitwise boolean operation on all input image channels (bands) to produce a single channel output image.
 
-**Parameters**
+### Parameters
 
--   `boolOp` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+-   `boolOp` **[String][2]** one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
 
-**Examples**
+### Examples
 
 ```javascript
 sharp('3-channel-rgb-input.png')
@@ -72,6 +82,18 @@ sharp('3-channel-rgb-input.png')
   });
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   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

@@ -1,13 +1,5 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
-
--   [background](#background)
--   [greyscale](#greyscale)
--   [grayscale](#grayscale)
--   [toColourspace](#tocolourspace)
--   [toColorspace](#tocolorspace)
-
 ## background
 
 Set the background for the `embed`, `flatten` and `extend` operations.
@@ -17,12 +9,26 @@ Delegates to the _color_ module, which can throw an Error
 but is liberal in what it accepts, clipping values to sensible min/max.
 The alpha value is a float between `0` (transparent) and `1` (opaque).
 
-**Parameters**
+### Parameters
 
--   `rgba` **([String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) \| [Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object))** parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+-   `rgba` **([String][1] \| [Object][2])** parsed by the [color][3] module to extract values for red, green, blue and alpha.
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameter
+-   Throws **[Error][4]** Invalid parameter
+
+Returns **Sharp** 
+
+## 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** 
 
@@ -35,9 +41,9 @@ 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**
+### Parameters
 
--   `greyscale` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+-   `greyscale` **[Boolean][5]**  (optional, default `true`)
 
 Returns **Sharp** 
 
@@ -45,9 +51,9 @@ Returns **Sharp**
 
 Alternative spelling of `greyscale`.
 
-**Parameters**
+### Parameters
 
--   `grayscale` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+-   `grayscale` **[Boolean][5]**  (optional, default `true`)
 
 Returns **Sharp** 
 
@@ -56,12 +62,12 @@ Returns **Sharp**
 Set the output colourspace.
 By default output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
 
-**Parameters**
+### Parameters
 
--   `colourspace` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)?** output colourspace e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568)
+-   `colourspace` **[String][1]?** output colourspace e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...][6]
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][4]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -69,11 +75,23 @@ Returns **Sharp**
 
 Alternative spelling of `toColourspace`.
 
-**Parameters**
+### Parameters
 
--   `colorspace` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)?** output colorspace.
+-   `colorspace` **[String][1]?** output colorspace.
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   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/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568

docs/api-composite.md

@@ -1,9 +1,5 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
-
--   [overlayWith](#overlaywith)
-
 ## overlayWith
 
 Overlay (composite) an image over the processed (resized, extracted etc.) image.
@@ -13,27 +9,27 @@ If both `top` and `left` options are provided, they take precedence over `gravit
 
 If the overlay image contains an alpha channel then composition with premultiplication will occur.
 
-**Parameters**
+### Parameters
 
--   `overlay` **([Buffer](https://nodejs.org/api/buffer.html) \| [String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String))** Buffer containing image data or String containing the path to an image file.
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-    -   `options.gravity` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** gravity at which to place the overlay. (optional, default `'centre'`)
-    -   `options.top` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** the pixel offset from the top edge.
-    -   `options.left` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** the pixel offset from the left edge.
-    -   `options.tile` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** set to true to repeat the overlay image across the entire image with the given `gravity`. (optional, default `false`)
-    -   `options.cutout` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** 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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** integral number representing the DPI for vector overlay image. (optional, default `72`)
-    -   `options.raw` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** describes overlay when using raw pixel data.
-        -   `options.raw.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.raw.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.raw.channels` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-    -   `options.create` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** describes a blank overlay to be created.
-        -   `options.create.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.create.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.create.channels` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 3-4
-        -   `options.create.background` **([String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) \| [Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object))?** parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+-   `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]** integral 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**
+### Examples
 
 ```javascript
 sharp('input.png')
@@ -44,8 +40,7 @@ sharp('input.png')
   .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
   .sharpen()
   .withMetadata()
-  .quality(90)
-  .webp()
+  .webp( { quality: 90 } )
   .toBuffer()
   .then(function(outputBuffer) {
     // outputBuffer contains upside down, 300px wide, alpha channel flattened
@@ -54,6 +49,20 @@ sharp('input.png')
   });
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   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

@@ -1,33 +1,30 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
-
--   [Sharp](#sharp)
-    -   [format](#format)
-    -   [versions](#versions)
--   [queue](#queue)
-
 ## Sharp
 
-**Parameters**
+### Parameters
 
--   `input` **([Buffer](https://nodejs.org/api/buffer.html) \| [String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String))?** if present, can be
+-   `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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** if present, is an Object with optional attributes.
-    -   `options.density` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** integral number representing the DPI for vector images. (optional, default `72`)
-    -   `options.raw` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** describes raw pixel input image data. See `raw()` for pixel ordering.
-        -   `options.raw.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.raw.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.raw.channels` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 1-4
-    -   `options.create` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** describes a new image to be created.
-        -   `options.create.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.create.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.create.channels` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 3-4
-        -   `options.create.background` **([String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) \| [Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object))?** parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+-   `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]** integral 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**
+### Examples
 
 ```javascript
 sharp('input.jpg')
@@ -58,7 +55,7 @@ sharp({
     width: 300,
     height: 200,
     channels: 4,
-    background: { r: 255, g: 0, b: 0, alpha: 128 }
+    background: { r: 255, g: 0, b: 0, alpha: 0.5 }
   }
 })
 .png()
@@ -66,27 +63,27 @@ sharp({
 .then( ... );
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][7]** Invalid parameters
 
-Returns **[Sharp](#sharp)** 
+Returns **[Sharp][8]** 
 
 ### format
 
 An Object containing nested boolean values representing the available input and output formats/methods.
 
-**Examples**
+#### Examples
 
 ```javascript
 console.log(sharp.format);
 ```
 
-Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
+Returns **[Object][3]** 
 
 ### versions
 
 An Object containing the version numbers of libvips and its dependencies.
 
-**Examples**
+#### Examples
 
 ```javascript
 console.log(sharp.versions);
@@ -99,10 +96,26 @@ An EventEmitter that emits a `change` event when a task is either:
 -   queued, waiting for _libuv_ to provide a worker thread
 -   complete
 
-**Examples**
+### 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

@@ -1,19 +1,12 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
-
--   [clone](#clone)
--   [metadata](#metadata)
--   [limitInputPixels](#limitinputpixels)
--   [sequentialRead](#sequentialread)
-
 ## 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**
+### Examples
 
 ```javascript
 const pipeline = sharp().rotate();
@@ -32,23 +25,25 @@ Fast access to (uncached) image metadata without decoding any compressed image d
 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`
--   `width`: Number of pixels wide
--   `height`: Number of pixels high
--   `space`: Name of colour space interpretation e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L636)
+-   `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` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L672)
+-   `depth`: Name of pixel depth format e.g. `uchar`, `char`, `ushort`, `float` [...][2]
 -   `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
+-   `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**
+### Parameters
 
--   `callback` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)?** called with the arguments `(err, metadata)`
+-   `callback` **[Function][4]?** called with the arguments `(err, metadata)`
 
-**Examples**
+### Examples
 
 ```javascript
 const image = sharp(inputJpg);
@@ -65,7 +60,43 @@ image
   });
 ```
 
-Returns **([Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)&lt;[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)> | Sharp)** 
+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
 
@@ -73,12 +104,12 @@ Do not process input images where the number of pixels (width _ height) exceeds
 Assumes image dimensions contained in the input metadata can be trusted.
 The default limit is 268402689 (0x3FFF _ 0x3FFF) pixels.
 
-**Parameters**
+### Parameters
 
--   `limit` **([Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number) \| [Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean))** an integral Number of pixels, zero or false to remove limit, true to use default limit.
+-   `limit` **([Number][7] \| [Boolean][8])** an integral Number of pixels, zero or false to remove limit, true to use default limit.
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid limit
+-   Throws **[Error][9]** Invalid limit
 
 Returns **Sharp** 
 
@@ -87,8 +118,28 @@ Returns **Sharp**
 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.
 
-**Parameters**
+The default behaviour _before_ function call is `false`, meaning the libvips access method is not sequential.
 
--   `sequentialRead` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+### Parameters
+
+-   `sequentialRead` **[Boolean][8]**  (optional, default `true`)
 
 Returns **Sharp** 
+
+[1]: https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L636
+
+[2]: https://github.com/jcupitt/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

@@ -1,24 +1,5 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
-
--   [rotate](#rotate)
--   [extract](#extract)
--   [flip](#flip)
--   [flop](#flop)
--   [sharpen](#sharpen)
--   [blur](#blur)
--   [extend](#extend)
--   [flatten](#flatten)
--   [trim](#trim)
--   [gamma](#gamma)
--   [negate](#negate)
--   [normalise](#normalise)
--   [normalize](#normalize)
--   [convolve](#convolve)
--   [threshold](#threshold)
--   [boolean](#boolean)
-
 ## rotate
 
 Rotate the output image by either an explicit angle
@@ -35,11 +16,11 @@ 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**
+### Parameters
 
--   `angle` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** angle of rotation, must be a multiple of 90. (optional, default `auto`)
+-   `angle` **[Number][1]** angle of rotation, must be a multiple of 90. (optional, default `auto`)
 
-**Examples**
+### Examples
 
 ```javascript
 const pipeline = sharp()
@@ -53,7 +34,7 @@ const pipeline = sharp()
 readableStream.pipe(pipeline);
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -65,15 +46,15 @@ Extract a region of the image.
 -   Use `extract` after `resize` for post-resize extraction.
 -   Use `extract` before and after for both.
 
-**Parameters**
+### Parameters
 
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
-    -   `options.left` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** zero-indexed offset from left edge
-    -   `options.top` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** zero-indexed offset from top edge
-    -   `options.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** dimension of extracted image
-    -   `options.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** dimension of extracted image
+-   `options` **[Object][3]** 
+    -   `options.left` **[Number][1]** zero-indexed offset from left edge
+    -   `options.top` **[Number][1]** zero-indexed offset from top edge
+    -   `options.width` **[Number][1]** dimension of extracted image
+    -   `options.height` **[Number][1]** dimension of extracted image
 
-**Examples**
+### Examples
 
 ```javascript
 sharp(input)
@@ -93,7 +74,7 @@ sharp(input)
   });
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -102,9 +83,9 @@ Returns **Sharp**
 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**
+### Parameters
 
--   `flip` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+-   `flip` **[Boolean][4]**  (optional, default `true`)
 
 Returns **Sharp** 
 
@@ -113,9 +94,9 @@ Returns **Sharp**
 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**
+### Parameters
 
--   `flop` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+-   `flop` **[Boolean][4]**  (optional, default `true`)
 
 Returns **Sharp** 
 
@@ -126,14 +107,28 @@ 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**
+### Parameters
 
--   `sigma` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
--   `flat` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the level of sharpening to apply to "flat" areas. (optional, default `1.0`)
--   `jagged` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the level of sharpening to apply to "jagged" areas. (optional, default `2.0`)
+-   `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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** 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][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -143,12 +138,12 @@ 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**
+### Parameters
 
--   `sigma` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+-   `sigma` **[Number][1]?** a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -157,15 +152,15 @@ Returns **Sharp**
 Extends/pads the edges of the image with the colour provided to the `background` method.
 This operation will always occur after resizing and extraction, if any.
 
-**Parameters**
+### Parameters
 
--   `extend` **([Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number) \| [Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object))** single pixel count to add to all edges or an Object with per-edge counts
-    -   `extend.top` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-    -   `extend.left` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-    -   `extend.bottom` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-    -   `extend.right` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
+-   `extend` **([Number][1] \| [Object][3])** single pixel count to add to all edges or an Object with per-edge counts
+    -   `extend.top` **[Number][1]?** 
+    -   `extend.left` **[Number][1]?** 
+    -   `extend.bottom` **[Number][1]?** 
+    -   `extend.right` **[Number][1]?** 
 
-**Examples**
+### Examples
 
 ```javascript
 // Resize to 140 pixels wide, then add 10 transparent pixels
@@ -177,7 +172,7 @@ sharp(input)
   ...
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -185,9 +180,9 @@ Returns **Sharp**
 
 Merge alpha transparency channel, if any, with `background`.
 
-**Parameters**
+### Parameters
 
--   `flatten` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+-   `flatten` **[Boolean][4]**  (optional, default `true`)
 
 Returns **Sharp** 
 
@@ -195,12 +190,12 @@ Returns **Sharp**
 
 Trim "boring" pixels from all edges that contain values within a percentage similarity of the top-left pixel.
 
-**Parameters**
+### Parameters
 
--   `tolerance` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** value between 1 and 99 representing the percentage similarity. (optional, default `10`)
+-   `tolerance` **[Number][1]** value between 1 and 99 representing the percentage similarity. (optional, default `10`)
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -212,12 +207,12 @@ This can improve the perceived brightness of a resized image in non-linear colou
 JPEG and WebP input images will not take advantage of the shrink-on-load performance optimisation
 when applying a gamma correction.
 
-**Parameters**
+### Parameters
 
--   `gamma` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** value between 1.0 and 3.0. (optional, default `2.2`)
+-   `gamma` **[Number][1]** value between 1.0 and 3.0. (optional, default `2.2`)
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -225,9 +220,9 @@ Returns **Sharp**
 
 Produce the "negative" of the image.
 
-**Parameters**
+### Parameters
 
--   `negate` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+-   `negate` **[Boolean][4]**  (optional, default `true`)
 
 Returns **Sharp** 
 
@@ -235,9 +230,9 @@ Returns **Sharp**
 
 Enhance output image contrast by stretching its luminance to cover the full dynamic range.
 
-**Parameters**
+### Parameters
 
--   `normalise` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+-   `normalise` **[Boolean][4]**  (optional, default `true`)
 
 Returns **Sharp** 
 
@@ -245,9 +240,9 @@ Returns **Sharp**
 
 Alternative spelling of normalise.
 
-**Parameters**
+### Parameters
 
--   `normalize` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+-   `normalize` **[Boolean][4]**  (optional, default `true`)
 
 Returns **Sharp** 
 
@@ -255,16 +250,16 @@ Returns **Sharp**
 
 Convolve the image with the specified kernel.
 
-**Parameters**
+### Parameters
 
--   `kernel` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
-    -   `kernel.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** width of the kernel in pixels.
-    -   `kernel.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** width of the kernel in pixels.
-    -   `kernel.kernel` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)&lt;[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)>** Array of length `width*height` containing the kernel values.
-    -   `kernel.scale` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the scale of the kernel in pixels. (optional, default `sum`)
-    -   `kernel.offset` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** the offset of the kernel in pixels. (optional, default `0`)
+-   `kernel` **[Object][3]** 
+    -   `kernel.width` **[Number][1]** width of the kernel in pixels.
+    -   `kernel.height` **[Number][1]** width of the kernel in pixels.
+    -   `kernel.kernel` **[Array][5]&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**
+### Examples
 
 ```javascript
 sharp(input)
@@ -280,7 +275,7 @@ sharp(input)
   });
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -288,15 +283,15 @@ Returns **Sharp**
 
 Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
 
-**Parameters**
+### Parameters
 
--   `threshold` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** a value in the range 0-255 representing the level at which the threshold will be applied. (optional, default `128`)
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-    -   `options.greyscale` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** convert to single channel greyscale. (optional, default `true`)
-    -   `options.grayscale` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** alternative spelling for greyscale. (optional, default `true`)
+-   `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][3]?** 
+    -   `options.greyscale` **[Boolean][4]** convert to single channel greyscale. (optional, default `true`)
+    -   `options.grayscale` **[Boolean][4]** alternative spelling for greyscale. (optional, default `true`)
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -307,17 +302,45 @@ 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**
+### Parameters
 
--   `operand` **([Buffer](https://nodejs.org/api/buffer.html) \| [String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String))** Buffer containing image data or String containing the path to an image file.
--   `operator` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-    -   `options.raw` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** describes operand when using raw pixel data.
-        -   `options.raw.width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.raw.height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
-        -   `options.raw.channels` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
+-   `operand` **([Buffer][6] \| [String][7])** Buffer containing image data or String containing the path to an image file.
+-   `operator` **[String][7]** one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+-   `options` **[Object][3]?** 
+    -   `options.raw` **[Object][3]?** describes operand when using raw pixel data.
+        -   `options.raw.width` **[Number][1]?** 
+        -   `options.raw.height` **[Number][1]?** 
+        -   `options.raw.channels` **[Number][1]?** 
 
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][2]** 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][2]** 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/Error
+
+[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/Array
+
+[6]: https://nodejs.org/api/buffer.html
+
+[7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String

docs/api-output.md

@@ -1,18 +1,5 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
-
--   [toFile](#tofile)
--   [toBuffer](#tobuffer)
--   [withMetadata](#withmetadata)
--   [jpeg](#jpeg)
--   [png](#png)
--   [webp](#webp)
--   [tiff](#tiff)
--   [raw](#raw)
--   [toFormat](#toformat)
--   [tile](#tile)
-
 ## toFile
 
 Write output image data to a file.
@@ -21,19 +8,33 @@ If an explicit output format is not selected, it will be inferred from the exten
 with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
 Note that raw pixel data is only supported for buffer output.
 
-A Promises/A+ promise is returned when `callback` is not provided.
+A `Promise` is returned when `callback` is not provided.
 
-**Parameters**
+### Parameters
 
--   `fileOut` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** the path to write the image data to.
--   `callback` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)?** called on completion with two arguments `(err, info)`.
+-   `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
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+```javascript
+sharp(input)
+  .toFile('output.png', (err, info) => { ... });
+```
 
-Returns **[Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)&lt;[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)>** when no callback is provided
+```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
 
@@ -47,15 +48,38 @@ By default, the format will match the input image, except GIF and SVG input whic
 -   `data` is the output image data.
 -   `info` contains the output image `format`, `size` (bytes), `width`, `height`,
     `channels` and `premultiplied` (indicating if premultiplication was used).
-    A Promise is returned when `callback` is not provided.
+    When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
 
-**Parameters**
+A `Promise` is returned when `callback` is not provided.
 
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-    -   `options.resolveWithObject` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?** Resolve the Promise with an Object containing `data` and `info` properties instead of resolving only with `data`.
--   `callback` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)?** 
+### Parameters
 
-Returns **[Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)&lt;[Buffer](https://nodejs.org/api/buffer.html)>** when no callback is provided
+-   `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
 
@@ -63,13 +87,21 @@ 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**
+### Parameters
 
--   `withMetadata` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-    -   `withMetadata.orientation` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** value between 1 and 8, used to update the EXIF `Orientation` tag.
+-   `withMetadata` **[Object][5]?** 
+    -   `withMetadata.orientation` **[Number][8]?** value between 1 and 8, used to update the EXIF `Orientation` tag.
 
+### Examples
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+```javascript
+sharp('input.jpg')
+  .withMetadata()
+  .toFile('output-with-metadata.jpg')
+  .then(info => { ... });
+```
+
+-   Throws **[Error][3]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -77,20 +109,35 @@ Returns **Sharp**
 
 Use these JPEG options for output image.
 
-**Parameters**
+### Parameters
 
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** output options
-    -   `options.quality` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** quality, integer 1-100 (optional, default `80`)
-    -   `options.progressive` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** use progressive (interlace) scan (optional, default `false`)
-    -   `options.chromaSubsampling` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** set to '4:4:4' to prevent chroma subsampling when quality &lt;= 90 (optional, default `'4:2:0'`)
-    -   `options.trellisQuantisation` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** apply trellis quantisation, requires mozjpeg (optional, default `false`)
-    -   `options.overshootDeringing` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** apply overshoot deringing, requires mozjpeg (optional, default `false`)
-    -   `options.optimiseScans` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** optimise progressive scans, forces progressive, requires mozjpeg (optional, default `false`)
-    -   `options.optimizeScans` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** alternative spelling of optimiseScans (optional, default `false`)
-    -   `options.force` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** force JPEG output, otherwise attempt to use input format (optional, default `true`)
+-   `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
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid options
+```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** 
 
@@ -98,16 +145,27 @@ Returns **Sharp**
 
 Use these PNG options for output image.
 
-**Parameters**
+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.
 
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-    -   `options.progressive` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** use progressive (interlace) scan (optional, default `false`)
-    -   `options.compressionLevel` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** zlib compression level (optional, default `6`)
-    -   `options.adaptiveFiltering` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** use adaptive row filtering (optional, default `true`)
-    -   `options.force` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** force PNG output, otherwise attempt to use input format (optional, default `true`)
+### 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.force` **[Boolean][6]** force PNG output, otherwise attempt to use input format (optional, default `true`)
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid options
+### Examples
+
+```javascript
+// Convert any input to PNG output
+const data = await sharp(input)
+  .png()
+  .toBuffer();
+```
+
+-   Throws **[Error][3]** Invalid options
 
 Returns **Sharp** 
 
@@ -115,17 +173,25 @@ Returns **Sharp**
 
 Use these WebP options for output image.
 
-**Parameters**
+### Parameters
 
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** output options
-    -   `options.quality` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** quality, integer 1-100 (optional, default `80`)
-    -   `options.alphaQuality` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** quality of alpha layer, integer 0-100 (optional, default `100`)
-    -   `options.lossless` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** use lossless compression mode (optional, default `false`)
-    -   `options.nearLossless` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** use near_lossless compression mode (optional, default `false`)
-    -   `options.force` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** force WebP output, otherwise attempt to use input format (optional, default `true`)
+-   `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
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid options
+```javascript
+// Convert any input to lossless WebP output
+const data = await sharp(input)
+  .webp({ lossless: true })
+  .toBuffer();
+```
+
+-   Throws **[Error][3]** Invalid options
 
 Returns **Sharp** 
 
@@ -133,19 +199,31 @@ Returns **Sharp**
 
 Use these TIFF options for output image.
 
-**Parameters**
+### Parameters
 
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** output options
-    -   `options.quality` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** quality, integer 1-100 (optional, default `80`)
-    -   `options.force` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** force TIFF output, otherwise attempt to use input format (optional, default `true`)
-    -   `options.compression` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** compression options: lzw, deflate, jpeg (optional, default `'jpeg'`)
-    -   `options.predictor` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** compression predictor options: none, horizontal, float (optional, default `'none'`)
-    -   `options.xres` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** horizontal resolution in pixels/mm (optional, default `1.0`)
-    -   `options.yres` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** vertical resolution in pixels/mm (optional, default `1.0`)
-    -   `options.squash` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** squash 8-bit images down to 1 bit (optional, default `false`)
+-   `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.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
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid options
+```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** 
 
@@ -153,19 +231,36 @@ Returns **Sharp**
 
 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**
+### Parameters
 
--   `format` **([String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) \| [Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object))** as a String or an Object with an 'id' attribute
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** output options
+-   `format` **([String][1] \| [Object][5])** as a String or an Object with an 'id' attribute
+-   `options` **[Object][5]** output options
 
+### Examples
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** unsupported format or options
+```javascript
+// Convert any input to PNG output
+const data = await sharp(input)
+  .toFormat('png')
+  .toBuffer();
+```
+
+-   Throws **[Error][3]** unsupported format or options
 
 Returns **Sharp** 
 
@@ -175,15 +270,19 @@ 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.
 
-**Parameters**
+Warning: multiple sharp instances concurrently producing tile output can expose a possible race condition in some versions of libgsf.
 
--   `tile` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-    -   `tile.size` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** tile size in pixels, a value between 1 and 8192. (optional, default `256`)
-    -   `tile.overlap` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** tile overlap in pixels, a value between 0 and 8192. (optional, default `0`)
-    -   `tile.container` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** tile container, with value `fs` (filesystem) or `zip` (compressed file). (optional, default `'fs'`)
-    -   `tile.layout` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** filesystem layout, possible values are `dz`, `zoomify` or `google`. (optional, default `'dz'`)
+### Parameters
 
-**Examples**
+-   `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')
@@ -197,6 +296,22 @@ sharp('input.tiff')
   });
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   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

@@ -1,65 +1,43 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
-
--   [resize](#resize)
--   [crop](#crop)
--   [embed](#embed)
--   [max](#max)
--   [min](#min)
--   [ignoreAspectRatio](#ignoreaspectratio)
--   [withoutEnlargement](#withoutenlargement)
-
 ## resize
 
 Resize image to `width` x `height`.
 By default, the resized image is centre cropped to the exact size specified.
 
-Possible reduction kernels are:
+Possible 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).
--   `lanczos2`: Use a [Lanczos kernel](https://en.wikipedia.org/wiki/Lanczos_resampling#Lanczos_kernel) with `a=2`.
+-   `nearest`: Use [nearest neighbour interpolation][1].
+-   `cubic`: Use a [Catmull-Rom spline][2].
+-   `lanczos2`: Use a [Lanczos kernel][3] with `a=2`.
 -   `lanczos3`: Use a Lanczos kernel with `a=3` (the default).
 
-Possible enlargement interpolators are:
+### Parameters
 
--   `nearest`: Use [nearest neighbour interpolation](http://en.wikipedia.org/wiki/Nearest-neighbor_interpolation).
--   `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.
+-   `width` **[Number][4]?** pixels wide the resultant image should be. Use `null` or `undefined` to auto-scale the width to match the height.
+-   `height` **[Number][4]?** pixels high the resultant image should be. Use `null` or `undefined` to auto-scale the height to match the width.
+-   `options` **[Object][5]?** 
+    -   `options.kernel` **[String][6]** the kernel to use for image reduction. (optional, default `'lanczos3'`)
+    -   `options.fastShrinkOnLoad` **[Boolean][7]** 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`)
 
-**Parameters**
-
--   `width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** pixels wide the resultant image should be. Use `null` or `undefined` to auto-scale the width to match the height.
--   `height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** pixels high the resultant image should be. Use `null` or `undefined` to auto-scale the height to match the width.
--   `options` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)?** 
-    -   `options.kernel` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** the kernel to use for image reduction. (optional, default `'lanczos3'`)
-    -   `options.interpolator` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** the interpolator to use for image enlargement. (optional, default `'bicubic'`)
-    -   `options.centreSampling` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** use \*magick centre sampling convention instead of corner sampling. (optional, default `false`)
-    -   `options.centerSampling` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** alternative spelling of centreSampling. (optional, default `false`)
-
-**Examples**
+### Examples
 
 ```javascript
 sharp(inputBuffer)
   .resize(200, 300, {
-    kernel: sharp.kernel.lanczos2,
-    interpolator: sharp.interpolator.nohalo
+    kernel: sharp.kernel.nearest
   })
   .background('white')
   .embed()
   .toFile('output.tiff')
   .then(function() {
     // output.tiff is a 200 pixels wide and 300 pixels high image
-    // containing a lanczos2/nohalo scaled version, embedded on a white canvas,
+    // containing a nearest-neighbour scaled version, embedded on a white canvas,
     // of the image data in inputBuffer
   });
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][8]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -73,14 +51,14 @@ Possible attributes of the optional `sharp.gravity` are `north`, `northeast`, `e
 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).
+-   `entropy`: focus on the region with the highest [Shannon entropy][9].
 -   `attention`: focus on the region with the highest luminance frequency, colour saturation and presence of skin tones.
 
-**Parameters**
+### Parameters
 
--   `crop` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** A member of `sharp.gravity` to crop to an edge/corner or `sharp.strategy` to crop dynamically. (optional, default `'centre'`)
+-   `crop` **[String][6]** A member of `sharp.gravity` to crop to an edge/corner or `sharp.strategy` to crop dynamically. (optional, default `'centre'`)
 
-**Examples**
+### Examples
 
 ```javascript
 const transformer = sharp()
@@ -94,7 +72,7 @@ const transformer = sharp()
 readableStream.pipe(transformer).pipe(writableStream);
 ```
 
--   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+-   Throws **[Error][8]** Invalid parameters
 
 Returns **Sharp** 
 
@@ -106,7 +84,11 @@ 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.
 
-**Examples**
+### Parameters
+
+-   `embed` **[String][6]** A member of `sharp.gravity` to embed to an edge/corner. (optional, default `'centre'`)
+
+### Examples
 
 ```javascript
 sharp('input.gif')
@@ -123,6 +105,8 @@ sharp('input.gif')
   });
 ```
 
+-   Throws **[Error][8]** Invalid parameters
+
 Returns **Sharp** 
 
 ## max
@@ -132,7 +116,7 @@ while ensuring its dimensions are less than or equal to the `width` and `height`
 
 Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
 
-**Examples**
+### Examples
 
 ```javascript
 sharp(inputBuffer)
@@ -169,9 +153,30 @@ Returns **Sharp**
 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_".
+Use with `max()` to preserve the image's aspect ratio.
 
-**Parameters**
+The default behaviour _before_ function call is `false`, meaning the image will be enlarged.
 
--   `withoutEnlargement` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `true`)
+### Parameters
+
+-   `withoutEnlargement` **[Boolean][7]**  (optional, default `true`)
 
 Returns **Sharp** 
+
+[1]: http://en.wikipedia.org/wiki/Nearest-neighbor_interpolation
+
+[2]: https://en.wikipedia.org/wiki/Centripetal_Catmull%E2%80%93Rom_spline
+
+[3]: https://en.wikipedia.org/wiki/Lanczos_resampling#Lanczos_kernel
+
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+
+[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+
+[7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+
+[8]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+
+[9]: https://en.wikipedia.org/wiki/Entropy_%28information_theory%29

docs/api-utility.md

@@ -1,12 +1,5 @@
 <!-- Generated by documentation.js. Update this documentation by updating the source code. -->
 
-### Table of Contents
-
--   [cache](#cache)
--   [concurrency](#concurrency)
--   [counters](#counters)
--   [simd](#simd)
-
 ## cache
 
 Gets or, when options are provided, sets the limits of _libvips'_ operation cache.
@@ -14,14 +7,14 @@ 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**
+### Parameters
 
--   `options` **([Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object) \| [Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean))** Object with the following attributes, or Boolean where true uses default cache settings and false removes all caching (optional, default `true`)
-    -   `options.memory` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** is the maximum memory in MB to use for this cache (optional, default `50`)
-    -   `options.files` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** is the maximum number of files to hold open (optional, default `20`)
-    -   `options.items` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** is the maximum number of operations to cache (optional, default `100`)
+-   `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**
+### Examples
 
 ```javascript
 const stats = sharp.cache();
@@ -33,7 +26,7 @@ sharp.cache( { files: 0 } );
 sharp.cache(false);
 ```
 
-Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
+Returns **[Object][1]** 
 
 ## concurrency
 
@@ -47,11 +40,11 @@ is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
 
 This method always returns the current concurrency.
 
-**Parameters**
+### Parameters
 
--   `concurrency` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
+-   `concurrency` **[Number][3]?** 
 
-**Examples**
+### Examples
 
 ```javascript
 const threads = sharp.concurrency(); // 4
@@ -59,7 +52,7 @@ sharp.concurrency(2); // 2
 sharp.concurrency(0); // 4
 ```
 
-Returns **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** concurrency
+Returns **[Number][3]** concurrency
 
 ## counters
 
@@ -68,13 +61,13 @@ 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**
+### Examples
 
 ```javascript
 const counters = sharp.counters(); // { queue: 2, process: 4 }
 ```
 
-Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
+Returns **[Object][1]** 
 
 ## simd
 
@@ -87,11 +80,11 @@ by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM N
 This feature is currently off by default but future versions may reverse this.
 Versions of liborc prior to 0.4.25 are known to segfault under heavy load.
 
-**Parameters**
+### Parameters
 
--   `simd` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)**  (optional, default `false`)
+-   `simd` **[Boolean][2]**  (optional, default `false`)
 
-**Examples**
+### Examples
 
 ```javascript
 const simd = sharp.simd();
@@ -103,4 +96,10 @@ const simd = sharp.simd(true);
 // attempts to enable the use of SIMD, returning true if available
 ```
 
-Returns **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** 
+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/changelog.md

@@ -1,9 +1,175 @@
 # Changelog
 
+### v0.20 - "*prebuild*"
+
+Requires libvips v8.6.1.
+
+#### 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.

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/index.md

@@ -13,8 +13,9 @@ 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.
 
-OS X, Windows (x64), Linux (x64, ARM) systems do not require
-the installation of any external runtime dependencies.
+Most 64-bit OS X, Windows and Linux (glibc) systems running
+Node versions 4, 6, 8 and 10
+do not require any additional install or runtime dependencies.
 
 [![Test Coverage](https://coveralls.io/repos/lovell/sharp/badge.png?branch=master)](https://coveralls.io/r/lovell/sharp?branch=master)
 
@@ -46,7 +47,7 @@ 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
 
@@ -55,9 +56,9 @@ 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
 
@@ -102,12 +103,25 @@ the help and code contributions of the following people:
 * [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)
 
 Thank you!
 
 ### Licence
 
-Copyright 2013, 2014, 2015, 2016, 2017 Lovell Fuller and contributors.
+Copyright 2013, 2014, 2015, 2016, 2017, 2018 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.

docs/install.md

@@ -8,37 +8,53 @@ npm install sharp
 yarn add sharp
 ```
 
-### Prerequisites
+## Prerequisites
 
 * Node v4.5.0+
+
+### Building from source
+
+Pre-compiled binaries for sharp are provided for use with
+Node versions 4, 6, 8 and 10 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/TooTallNate/node-gyp#installation) and its dependencies (includes Python)
 
+## libvips
+
 ### Linux
 
-[![Ubuntu 14.04 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)
+[![Ubuntu 16.04 Build Status](https://travis-ci.org/lovell/sharp.png?branch=master)](https://travis-ci.org/lovell/sharp)
 
 libvips and its dependencies are fetched and stored within `node_modules/sharp/vendor` during `npm install`.
 This involves an automated HTTPS download of approximately 7MB.
 
 Most recent Linux-based operating systems with glibc running on x64 and ARMv6+ CPUs should "just work", e.g.:
 
-* Debian 7, 8
-* Ubuntu 12.04, 14.04, 16.04
-* Centos 7
+* Debian 7+
+* Ubuntu 14.04+
+* Centos 7+
 * Fedora
-* openSUSE 13.2
+* openSUSE 13.2+
 * Archlinux
 * Raspbian Jessie
-* Amazon Linux 2016.03, 2016.09
+* Amazon Linux
 * Solus
 
 To use a globally-installed version of libvips instead of the provided binaries,
 make sure it is 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`.
 
-If you are using non-stadard paths (anything other than `/usr` or `/usr/local`),
+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.
 
@@ -64,7 +80,7 @@ via `sharp.cache(false)` to avoid a stack overflow.
 
 ### 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 and its dependencies are fetched and stored within `node_modules/sharp/vendor` during `npm install`.
 This involves an automated HTTPS download of approximately 7MB.
@@ -78,14 +94,19 @@ that it can be located using `pkg-config --modversion vips-cpp`.
 [![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\vendor` during `npm install`.
-This involves an automated HTTPS download of approximately 11MB.
+This involves an automated HTTPS download of approximately 12MB.
 
 Only 64-bit (x64) `node.exe` is supported.
 
 ### 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
@@ -127,36 +148,40 @@ 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
-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 dependencies:
+A [deployment package](http://docs.aws.amazon.com/lambda/latest/dg/nodejs-create-deployment-pkg.html) for the
+[Lambda Execution Environment](http://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html)
+can be built using Docker.
 
 ```sh
-curl -s https://rpm.nodesource.com/setup_4.x | sudo bash -
-sudo yum install -y gcc-c++ nodejs
+rm -rf node_modules/sharp
+docker run -v "$PWD":/var/task lambci/lambda:build-nodejs6.10 npm install
 ```
 
-Copy your code and package.json to the instance using `scp` and create a deployment package:
+Set the Lambda runtime to Node.js 6.10.
+
+To get the best performance select the largest memory available. A 1536 MB function provides ~12x more CPU time than a 128 MB function.
+
+### NW.js
+
+Run the `nw-gyp` tool after installation.
 
 ```sh
-cd sharp-lambda-example
-npm install
-zip -ur9 ../sharp-lambda-example.zip index.js node_modules
+cd node-modules/sharp
+nw-gyp rebuild --arch=x64 --target=[your nw version]
+node node_modules/sharp/install/dll-copy
 ```
 
-You can now download your deployment ZIP using `scp` and upload it to Lambda. Be sure to set your Lambda runtime to Node.js 4.3.
-
-**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).
+See also 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)
@@ -198,13 +223,20 @@ to the directory containing the `policy.xml` file.
 
 ### Pre-compiled libvips binaries
 
-If a global installation of libvips that meets the
-minimum version requirement cannot be found,
-this module will attempt to download a pre-compiled bundle of libvips
-and its dependencies on Linux and Windows machines.
+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://dl.bintray.com/lovell/sharp/
+you can do so via https://github.com/lovell/sharp-libvips/releases
 
 Should you wish to install these from your own location,
 set the `SHARP_DIST_BASE_URL` environment variable, e.g.

docs/performance.md

@@ -2,19 +2,20 @@
 
 ### Test environment
 
-* AWS EC2 eu-central-1 [c4.xlarge](http://aws.amazon.com/ec2/instance-types/#c4) (4x E5-2666 v3 @ 2.90GHz)
-* Ubuntu 16.04.1 LTS (HVM, SSD, 20161115, ami-82cf0aed)
-* Node.js v6.9.1
+* AWS EC2 eu-west-1 [c5.large](https://aws.amazon.com/ec2/instance-types/c5/) (2x Xeon Platinum 8124M CPU @ 3.00GHz)
+* Ubuntu 17.10 (hvm:ebs-ssd, 20180102, ami-0741d47e)
+* Node.js v8.9.4
 
 ### The contenders
 
-* [jimp](https://www.npmjs.com/package/jimp) v0.2.27 - Image processing in pure JavaScript. Bilinear interpolation only.
-* [lwip](https://www.npmjs.com/package/lwip) v0.0.9 - Wrapper around CImg. Compiles outdated, insecure dependencies from source.
-* [mapnik](https://www.npmjs.org/package/mapnik) v3.5.14 - Whilst primarily a map renderer, Mapnik contains bitmap image utilities.
+* [jimp](https://www.npmjs.com/package/jimp) v0.2.28 - Image processing in pure JavaScript. Bilinear interpolation only.
+* [pajk-lwip](https://www.npmjs.com/package/pajk-lwip) v0.2.0 (fork) - Wrapper around CImg that compiles dependencies from source.
+* [mapnik](https://www.npmjs.org/package/mapnik) v3.6.2 - Whilst primarily a map renderer, Mapnik contains bitmap image utilities.
 * [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) v1.23.0 - Fully featured wrapper around GraphicsMagick's `gm` command line utility.
-* sharp v0.17.0 / libvips v8.4.2 - Caching within libvips disabled to ensure a fair comparison.
+* [gm](https://www.npmjs.com/package/gm) v1.23.1 - Fully featured wrapper around GraphicsMagick's `gm` command line utility.
+* [images](https://www.npmjs.com/package/images) v3.0.1 - Compiles dependencies from source. Provides bicubic interpolation.
+* sharp v0.19.0 / libvips v8.6.1 - Caching within libvips disabled to ensure a fair comparison.
 
 ### The task
 
@@ -26,18 +27,19 @@ then compress to JPEG at a "quality" setting of 80.
 
 | Module             | Input  | Output | Ops/sec | Speed-up |
 | :----------------- | :----- | :----- | ------: | -------: |
-| jimp (bilinear)    | buffer | buffer |    1.06 |      1.0 |
-| lwip               | buffer | buffer |    1.87 |      1.8 |
-| mapnik             | buffer | buffer |    2.91 |      2.7 |
-| imagemagick-native | buffer | buffer |    4.03 |      3.8 |
-| imagemagick        | file   | file   |    7.10 |      6.7 |
-| gm                 | buffer | buffer |    7.08 |      6.7 |
-| gm                 | file   | file   |    7.10 |      6.7 |
-| sharp              | stream | stream |   27.61 |     26.0 |
-| sharp              | file   | file   |   28.41 |     26.8 |
-| sharp              | buffer | file   |   28.71 |     27.1 |
-| sharp              | file   | buffer |   28.60 |     27.0 |
-| sharp              | buffer | buffer |   29.08 |     27.4 |
+| jimp (bilinear)    | buffer | buffer |    1.14 |      1.0 |
+| lwip               | buffer | buffer |    1.86 |      1.6 |
+| mapnik             | buffer | buffer |    3.34 |      2.9 |
+| imagemagick-native | buffer | buffer |    4.13 |      3.6 |
+| gm                 | buffer | buffer |    4.21 |      3.7 |
+| gm                 | file   | file   |    4.27 |      3.7 |
+| imagemagick        | file   | file   |    4.67 |      4.1 |
+| images (bicubic)   | file   | file   |    6.22 |      5.5 |
+| sharp              | stream | stream |   24.43 |     21.4 |
+| sharp              | file   | file   |   25.97 |     22.7 |
+| sharp              | file   | buffer |   26.00 |     22.8 |
+| sharp              | buffer | file   |   26.33 |     23.0 |
+| sharp              | buffer | buffer |   26.43 |     23.1 |
 
 Greater libvips performance can be expected with caching enabled (default)
 and using 8+ core machines, especially those with larger L1/L2 CPU caches.
@@ -46,19 +48,20 @@ The I/O limits of the relevant (de)compression library will generally determine
 
 ### 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 mapnik-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 +1,34 @@
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+
+const copyFileSync = require('fs-copy-file-sync');
+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 {
+    fs.mkdirSync(buildDir);
+    fs.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 +1,102 @@
+'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.SHARP_DIST_BASE_URL || `https://github.com/lovell/sharp-libvips/releases/download/v${minimumLibvipsVersion}/`;
+
+const extractTarball = function (tarPath) {
+  const vendorPath = path.join(__dirname, '..', 'vendor');
+  if (!fs.existsSync(vendorPath)) {
+    fs.mkdirSync(vendorPath);
+  }
+  tar
+    .extract({
+      file: tarPath,
+      cwd: vendorPath,
+      strict: true
+    })
+    .catch(function (err) {
+      throw err;
+    });
+};
+
+try {
+  const useGlobalLibvips = libvips.useGlobalLibvips();
+  if (useGlobalLibvips) {
+    const globalLibvipsVersion = libvips.globalLibvipsVersion();
+    npmLog.info('sharp', `Detected globally-installed libvips v${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') {
+      throw new Error(`FreeBSD systems require manual installation of libvips >= ${minimumLibvipsVersion}`);
+    }
+    if (detectLibc.isNonGlibcLinux) {
+      throw new Error(`Use with ${detectLibc.family} libc requires 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.pipe(tmpFile);
+      });
+      tmpFile.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) {
+  npmLog.error('sharp', err.message);
+  npmLog.error('sharp', 'Please see http://sharp.pixelplumbing.com/page/install');
+  process.exit(1);
+}

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

@@ -12,6 +12,23 @@ const bool = {
   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;
+}
+
 /**
  * Extract a single channel from a multi-channel image.
  *
@@ -102,6 +119,7 @@ function bandbool (boolOp) {
 module.exports = function (Sharp) {
   // Public instance functions
   [
+    removeAlpha,
     extractChannel,
     joinChannel,
     bandbool

lib/colour.js

@@ -38,6 +38,21 @@ function background (rgba) {
   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.
@@ -95,6 +110,7 @@ module.exports = function (Sharp) {
   // Public instance functions
   [
     background,
+    tint,
     greyscale,
     grayscale,
     toColourspace,

lib/composite.js

@@ -19,8 +19,7 @@ const is = require('./is');
  *   .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
  *   .sharpen()
  *   .withMetadata()
- *   .quality(90)
- *   .webp()
+ *   .webp( { quality: 90 } )
  *   .toBuffer()
  *   .then(function(outputBuffer) {
  *     // outputBuffer contains upside down, 300px wide, alpha channel flattened

lib/constructor.js

@@ -6,8 +6,24 @@ const stream = require('stream');
 const events = require('events');
 const semver = require('semver');
 const is = require('./is');
+const platform = require('./platform');
 const sharp = require('../build/Release/sharp.node');
 
+// Vendor platform
+(function () {
+  let vendorPlatformId;
+  try {
+    vendorPlatformId = require('../vendor/platform.json');
+  } catch (err) {
+    return;
+  }
+  const currentPlatformId = platform();
+  /* istanbul ignore if */
+  if (currentPlatformId !== vendorPlatformId) {
+    throw new Error(`'${vendorPlatformId}' binaries cannot be used on the '${currentPlatformId}' platform. Please remove the 'node_modules/sharp/vendor' directory and run 'npm rebuild'.`);
+  }
+})();
+
 // Versioning
 let versions = {
   vips: sharp.libvipsVersion()
@@ -21,7 +37,7 @@ let versions = {
   }
   // Include versions of dependencies, if present
   try {
-    versions = require('../vendor/lib/versions.json');
+    versions = require('../vendor/versions.json');
   } catch (err) {}
 })();
 
@@ -65,7 +81,7 @@ const debuglog = util.debuglog('sharp');
  *     width: 300,
  *     height: 200,
  *     channels: 4,
- *     background: { r: 255, g: 0, b: 0, alpha: 128 }
+ *     background: { r: 255, g: 0, b: 0, alpha: 0.5 }
  *   }
  * })
  * .png()
@@ -77,7 +93,11 @@ const debuglog = util.debuglog('sharp');
  *  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] - integral 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]
@@ -117,6 +137,7 @@ const Sharp = function (input, options) {
     height: -1,
     canvas: 'crop',
     crop: 0,
+    embed: 0,
     useExifOrientation: false,
     angle: 0,
     rotateBeforePreExtract: false,
@@ -128,12 +149,14 @@ const Sharp = function (input, options) {
     extendRight: 0,
     withoutEnlargement: false,
     kernel: 'lanczos3',
-    interpolator: 'bicubic',
-    centreSampling: false,
+    fastShrinkOnLoad: true,
     // operations
     background: [0, 0, 0, 255],
+    tintA: 128,
+    tintB: 128,
     flatten: false,
     negate: false,
+    medianSize: 0,
     blurSigma: 0,
     sharpenSigma: 0,
     sharpenFlat: 1,
@@ -148,6 +171,7 @@ const Sharp = function (input, options) {
     booleanFileIn: '',
     joinChannelIn: [],
     extractChannel: -1,
+    removeAlpha: false,
     colourspace: 'srgb',
     // overlay
     overlayGravity: 0,
@@ -169,21 +193,25 @@ const Sharp = function (input, options) {
     jpegTrellisQuantisation: false,
     jpegOvershootDeringing: false,
     jpegOptimiseScans: false,
+    jpegOptimiseCoding: true,
+    jpegQuantisationTable: 0,
     pngProgressive: false,
-    pngCompressionLevel: 6,
-    pngAdaptiveFiltering: true,
+    pngCompressionLevel: 9,
+    pngAdaptiveFiltering: false,
     webpQuality: 80,
     webpAlphaQuality: 100,
     webpLossless: false,
     webpNearLossless: false,
     tiffQuality: 80,
     tiffCompression: 'jpeg',
-    tiffPredictor: 'none',
+    tiffPredictor: 'horizontal',
     tiffSquash: false,
     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

lib/index.js

@@ -1,17 +1,13 @@
 'use strict';
 
 const Sharp = require('./constructor');
-[
-  'input',
-  'resize',
-  'composite',
-  'operation',
-  'colour',
-  'channel',
-  'output',
-  'utility'
-].forEach(function (decorator) {
-  require('./' + decorator)(Sharp);
-});
+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

@@ -9,7 +9,7 @@ const sharp = require('../build/Release/sharp.node');
  * @private
  */
 function _createInputDescriptor (input, inputOptions, containerOptions) {
-  const inputDescriptor = {};
+  const inputDescriptor = { failOnError: false };
   if (is.string(input)) {
     // filesystem
     inputDescriptor.file = input;
@@ -26,6 +26,14 @@ function _createInputDescriptor (input, inputOptions, containerOptions) {
     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.integer(inputOptions.density) && is.inRange(inputOptions.density, 1, 2400)) {
@@ -49,6 +57,12 @@ function _createInputDescriptor (input, inputOptions, containerOptions) {
         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 (
@@ -147,12 +161,14 @@ function clone () {
   const clone = this.constructor.call();
   clone.options = Object.assign({}, this.options);
   // Pass 'finish' event to clone for Stream-based input
-  this.on('finish', function () {
-    // Clone inherits input data
-    that._flattenBufferIn();
-    clone.options.bufferIn = that.options.bufferIn;
-    clone.emit('finish');
-  });
+  if (this._isStreamInput()) {
+    this.on('finish', function () {
+      // Clone inherits input data
+      that._flattenBufferIn();
+      clone.options.bufferIn = that.options.bufferIn;
+      clone.emit('finish');
+    });
+  }
   return clone;
 }
 
@@ -161,8 +177,8 @@ function clone () {
  * 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`
- * - `width`: Number of pixels wide
- * - `height`: Number of pixels high
+ * - `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/jcupitt/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/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L672)
@@ -172,6 +188,8 @@ function clone () {
  * - `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);
@@ -230,6 +248,75 @@ function metadata (callback) {
   }
 }
 
+/**
+ * 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.
@@ -256,6 +343,9 @@ function limitInputPixels (limit) {
 /**
  * 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}
  */
@@ -278,6 +368,7 @@ module.exports = function (Sharp) {
     // Public
     clone,
     metadata,
+    stats,
     limitInputPixels,
     sequentialRead
   ].forEach(function (f) {

lib/libvips.js

@@ -0,0 +1,82 @@
+'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 cachePath = function () {
+  const npmCachePath = env.npm_config_cache || (env.APPDATA ? path.join(env.APPDATA, 'npm-cache') : path.join(os.homedir(), '.npm'));
+  if (!fs.existsSync(npmCachePath)) {
+    fs.mkdirSync(npmCachePath);
+  }
+  const libvipsCachePath = path.join(npmCachePath, '_libvips');
+  if (!fs.existsSync(libvipsCachePath)) {
+    fs.mkdirSync(libvipsCachePath);
+  }
+  return libvipsCachePath;
+};
+
+const globalLibvipsVersion = function () {
+  if (process.platform !== 'win32') {
+    const globalLibvipsVersion = spawnSync(`PKG_CONFIG_PATH="${pkgConfigPath()}" pkg-config --modversion vips-cpp`, spawnSyncOptions).stdout || '';
+    return globalLibvipsVersion.trim();
+  } else {
+    return '';
+  }
+};
+
+const hasVendoredLibvips = function () {
+  const currentPlatformId = platform();
+  let vendorPlatformId;
+  try {
+    vendorPlatformId = require(path.join(__dirname, '..', 'vendor', 'platform.json'));
+  } catch (err) {}
+  if (vendorPlatformId) {
+    if (currentPlatformId === vendorPlatformId) {
+      return true;
+    } else {
+      throw new Error(`'${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
+};

lib/operation.js

@@ -156,6 +156,26 @@ function sharpen (sigma, flat, jagged) {
   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.
@@ -332,7 +352,7 @@ function convolve (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');
   }
@@ -406,6 +426,33 @@ function boolean (operand, operator, options) {
   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;
+}
+
 /**
  * Decorate the Sharp prototype with operation-related functions.
  * @private
@@ -417,6 +464,7 @@ module.exports = function (Sharp) {
     flip,
     flop,
     sharpen,
+    median,
     blur,
     extend,
     flatten,
@@ -427,7 +475,8 @@ module.exports = function (Sharp) {
     normalize,
     convolve,
     threshold,
-    boolean
+    boolean,
+    linear
   ].forEach(function (f) {
     Sharp.prototype[f.name] = f;
   });

lib/output.js

@@ -10,12 +10,23 @@ const sharp = require('../build/Release/sharp.node');
  * with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
  * Note that raw pixel data is only supported for buffer output.
  *
- * A Promises/A+ promise is returned when `callback` is not provided.
+ * 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
  */
@@ -53,7 +64,25 @@ function toFile (fileOut, callback) {
  * - `data` is the output image data.
  * - `info` contains the output image `format`, `size` (bytes), `width`, `height`,
  * `channels` and `premultiplied` (indicating if premultiplication was used).
- * A Promise is returned when `callback` is not provided.
+ * 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`.
@@ -73,6 +102,13 @@ function toBuffer (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}
@@ -94,6 +130,16 @@ function withMetadata (withMetadata) {
 
 /**
  * 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
@@ -102,6 +148,10 @@ function withMetadata (withMetadata) {
  * @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
@@ -139,16 +189,38 @@ function jpeg (options) {
         this.options.jpegProgressive = true;
       }
     }
+    options.optimiseCoding = is.bool(options.optimizeCoding) ? options.optimizeCoding : options.optimiseCoding;
+    if (is.defined(options.optimiseCoding)) {
+      this._setBooleanOption('jpegOptimiseCoding', options.optimiseCoding);
+    }
+    options.quantisationTable = is.number(options.quantizationTable) ? options.quantizationTable : options.quantisationTable;
+    if (is.defined(options.quantisationTable)) {
+      if (is.integer(options.quantisationTable) && is.inRange(options.quantisationTable, 0, 8)) {
+        this.options.jpegQuantisationTable = options.quantisationTable;
+      } else {
+        throw new Error('Invalid quantisation table (integer, 0-8) ' + options.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=6] - zlib compression level
- * @param {Boolean} [options.adaptiveFiltering=true] - use adaptive row filtering
+ * @param {Number} [options.compressionLevel=9] - zlib compression level, 0-9
+ * @param {Boolean} [options.adaptiveFiltering=false] - use adaptive row filtering
  * @param {Boolean} [options.force=true] - force PNG output, otherwise attempt to use input format
  * @returns {Sharp}
  * @throws {Error} Invalid options
@@ -174,6 +246,13 @@ function 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
@@ -192,10 +271,10 @@ function webp (options) {
     }
   }
   if (is.object(options) && is.defined(options.alphaQuality)) {
-    if (is.integer(options.alphaQuality) && is.inRange(options.alphaQuality, 1, 100)) {
+    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, 1-100) ' + options.alphaQuality);
+      throw new Error('Invalid webp alpha quality (integer, 0-100) ' + options.alphaQuality);
     }
   }
   if (is.object(options) && is.defined(options.lossless)) {
@@ -209,11 +288,22 @@ function 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
- * @param {Boolean} [options.predictor='none'] - compression predictor options: none, horizontal, float
+ * @param {Boolean} [options.compression='jpeg'] - compression options: lzw, deflate, jpeg, ccittfax4
+ * @param {Boolean} [options.predictor='horizontal'] - compression predictor options: none, horizontal, float
  * @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
@@ -252,10 +342,10 @@ function tiff (options) {
   }
   // compression
   if (is.defined(options) && is.defined(options.compression)) {
-    if (is.string(options.compression) && is.inArray(options.compression, ['lzw', 'deflate', 'jpeg', 'none'])) {
+    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 "${options.compression}". Should be one of: lzw, deflate, jpeg, none`;
+      const message = `Invalid compression option "${options.compression}". Should be one of: lzw, deflate, jpeg, ccittfax4, none`;
       throw new Error(message);
     }
   }
@@ -273,6 +363,13 @@ function 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 () {
@@ -281,6 +378,13 @@ function 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}
@@ -302,6 +406,8 @@ function toFormat (format, options) {
  * 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()
@@ -316,6 +422,8 @@ function toFormat (format, options) {
  * @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}
@@ -358,6 +466,24 @@ function tile (tile) {
         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'])) {
@@ -365,6 +491,7 @@ function tile (tile) {
   } else if (this.options.formatOut !== 'input') {
     throw new Error('Invalid tile format ' + this.options.formatOut);
   }
+
   return this._updateFormatOut('dz');
 }
 

lib/platform.js

@@ -0,0 +1,15 @@
+'use strict';
+
+module.exports = function () {
+  const arch = process.env.npm_config_arch || process.arch;
+  const platform = process.env.npm_config_platform || process.platform;
+
+  const platformId = [platform];
+  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

@@ -42,52 +42,27 @@ const kernel = {
   lanczos3: 'lanczos3'
 };
 
-/**
- * Enlargement interpolators.
- * @member
- * @private
- */
-const interpolator = {
-  nearest: 'nearest',
-  bilinear: 'bilinear',
-  bicubic: 'bicubic',
-  nohalo: 'nohalo',
-  lbb: 'lbb',
-  locallyBoundedBicubic: 'lbb',
-  vsqbs: 'vsqbs',
-  vertexSplitQuadraticBasisSpline: 'vsqbs'
-};
-
 /**
  * Resize image to `width` x `height`.
  * By default, the resized image is centre cropped to the exact size specified.
  *
- * Possible reduction kernels are:
+ * Possible 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).
  * - `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).
  *
- * Possible enlargement interpolators are:
- * - `nearest`: Use [nearest neighbour interpolation](http://en.wikipedia.org/wiki/Nearest-neighbor_interpolation).
- * - `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.
- *
  * @example
  * sharp(inputBuffer)
  *   .resize(200, 300, {
- *     kernel: sharp.kernel.lanczos2,
- *     interpolator: sharp.interpolator.nohalo
+ *     kernel: sharp.kernel.nearest
  *   })
  *   .background('white')
  *   .embed()
  *   .toFile('output.tiff')
  *   .then(function() {
  *     // output.tiff is a 200 pixels wide and 300 pixels high image
- *     // containing a lanczos2/nohalo scaled version, embedded on a white canvas,
+ *     // containing a nearest-neighbour scaled version, embedded on a white canvas,
  *     // of the image data in inputBuffer
  *   });
  *
@@ -95,9 +70,7 @@ const interpolator = {
  * @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.kernel='lanczos3'] - the kernel to use for image reduction.
- * @param {String} [options.interpolator='bicubic'] - the interpolator to use for image enlargement.
- * @param {Boolean} [options.centreSampling=false] - use *magick centre sampling convention instead of corner sampling.
- * @param {Boolean} [options.centerSampling=false] - alternative spelling of centreSampling.
+ * @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
  */
@@ -129,18 +102,9 @@ function resize (width, height, options) {
         throw is.invalidParameterError('kernel', 'valid kernel name', options.kernel);
       }
     }
-    // Interpolator
-    if (is.defined(options.interpolator)) {
-      if (is.string(interpolator[options.interpolator])) {
-        this.options.interpolator = interpolator[options.interpolator];
-      } else {
-        throw is.invalidParameterError('interpolator', 'valid interpolator name', options.interpolator);
-      }
-    }
-    // Centre sampling
-    options.centreSampling = is.bool(options.centerSampling) ? options.centerSampling : options.centreSampling;
-    if (is.defined(options.centreSampling)) {
-      this._setBooleanOption('centreSampling', options.centreSampling);
+    // Shrink on load
+    if (is.defined(options.fastShrinkOnLoad)) {
+      this._setBooleanOption('fastShrinkOnLoad', options.fastShrinkOnLoad);
     }
   }
   return this;
@@ -215,11 +179,26 @@ function crop (crop) {
  *     // 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
  *   });
- *
+ * @param {String} [embed='centre'] - A member of `sharp.gravity` to embed to an edge/corner.
  * @returns {Sharp}
+ * @throws {Error} Invalid parameters
  */
-function embed () {
+function embed (embed) {
   this.options.canvas = 'embed';
+
+  if (!is.defined(embed)) {
+    // Default
+    this.options.embed = gravity.center;
+  } else if (is.integer(embed) && is.inRange(embed, 0, 8)) {
+    // Gravity (numeric)
+    this.options.embed = embed;
+  } else if (is.string(embed) && is.integer(gravity[embed])) {
+    // Gravity (string)
+    this.options.embed = gravity[embed];
+  } else {
+    throw is.invalidParameterError('embed', 'valid embed id/name', embed);
+  }
+
   return this;
 }
 
@@ -274,6 +253,10 @@ function ignoreAspectRatio () {
  * 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*".
+ * Use with `max()` to preserve the image's aspect ratio.
+ *
+ * The default behaviour *before* function call is `false`, meaning the image will be enlarged.
+ *
  * @param {Boolean} [withoutEnlargement=true]
  * @returns {Sharp}
 */
@@ -302,5 +285,4 @@ module.exports = function (Sharp) {
   Sharp.gravity = gravity;
   Sharp.strategy = strategy;
   Sharp.kernel = kernel;
-  Sharp.interpolator = interpolator;
 };

mkdocs.yml

@@ -5,6 +5,8 @@ site_description: High performance Node.js image processing, the fastest module
 copyright: <a href="https://pixelplumbing.com/">pixelplumbing.com</a>
 google_analytics: ['UA-13034748-12', 'sharp.pixelplumbing.com']
 theme: readthedocs
+extra_css:
+  - css/extra.css
 markdown_extensions:
   - toc:
       permalink: True

package.json

@@ -1,7 +1,7 @@
 {
   "name": "sharp",
   "description": "High performance Node.js image processing, the fastest module to resize JPEG, PNG, WebP and TIFF images",
-  "version": "0.18.3",
+  "version": "0.20.7",
   "author": "Lovell Fuller <npm@lovell.info>",
   "homepage": "https://github.com/lovell/sharp",
   "contributors": [
@@ -38,14 +38,29 @@
     "YvesBos <yves_bos@outlook.com>",
     "Guy Maliar <guy@tailorbrands.com>",
     "Nicolas Coden <nicolas@ncoden.fr>",
-    "Matt Parrish <matt.r.parrish@gmail.com>"
+    "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>"
   ],
   "scripts": {
+    "install": "(node install/libvips && node install/dll-copy && prebuild-install) || (node-gyp rebuild && node install/dll-copy)",
     "clean": "rm -rf node_modules/ build/ vendor/ coverage/ test/fixtures/output.*",
-    "test": "semistandard && cc && nyc --reporter=lcov --branches=99 mocha --slow=5000 --timeout=60000 ./test/unit/*.js",
+    "test": "semistandard && cc && nyc --reporter=lcov --branches=99 mocha --slow=5000 --timeout=60000 ./test/unit/*.js && prebuild-ci",
+    "coverage": "./test/coverage/report.sh",
     "test-leak": "./test/leak/leak.sh",
-    "test-packaging": "./packaging/test-linux-x64.sh",
-    "docs": "for m in constructor input resize composite operation colour channel output utility; do documentation build --shallow --format=md lib/$m.js >docs/api-$m.md; done"
+    "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"
   },
   "main": "lib/index.js",
   "repository": {
@@ -64,33 +79,39 @@
     "resize",
     "thumbnail",
     "crop",
+    "embed",
     "libvips",
     "vips"
   ],
   "dependencies": {
-    "caw": "^2.0.0",
-    "color": "^2.0.0",
-    "detect-libc": "^0.2.0",
-    "nan": "^2.6.2",
-    "semver": "^5.3.0",
-    "simple-get": "^2.7.0",
-    "tar": "^3.1.5"
+    "color": "^3.0.0",
+    "detect-libc": "^1.0.3",
+    "nan": "^2.10.0",
+    "fs-copy-file-sync": "^1.1.1",
+    "npmlog": "^4.1.2",
+    "prebuild-install": "^4.0.0",
+    "semver": "^5.5.1",
+    "simple-get": "^2.8.1",
+    "tar": "^4.4.6",
+    "tunnel-agent": "^0.6.0"
   },
   "devDependencies": {
-    "async": "^2.5.0",
-    "cc": "^1.0.1",
-    "documentation": "^4.0.0-rc.1",
+    "async": "^2.6.1",
+    "cc": "^1.0.2",
+    "decompress-zip": "^0.3.1",
+    "documentation": "^8.1.1",
     "exif-reader": "^1.0.2",
     "icc": "^1.0.0",
-    "mocha": "^3.4.2",
-    "nyc": "^11.0.3",
-    "rimraf": "^2.6.1",
-    "semistandard": "^11.0.0",
-    "unzip": "^0.1.11"
+    "mocha": "^5.2.0",
+    "nyc": "^12.0.2",
+    "prebuild": "^7.6.2",
+    "prebuild-ci": "^2.2.3",
+    "rimraf": "^2.6.2",
+    "semistandard": "^12.0.1"
   },
   "license": "Apache-2.0",
   "config": {
-    "libvips": "8.5.5"
+    "libvips": "8.6.1"
   },
   "engines": {
     "node": ">=4.5.0"
@@ -105,7 +126,8 @@
     "filter": [
       "build/c++11",
       "build/include",
-      "runtime/indentation_namespace"
+      "runtime/indentation_namespace",
+      "runtime/references"
     ]
   }
 }

packaging/README.md

@@ -1,57 +0,0 @@
-# Packaging scripts
-
-libvips and its dependencies are provided as pre-compiled shared libraries
-for the most common operating systems and CPU architectures.
-
-During `npm install`, these binaries are fetched as tarballs from
-[Bintray](https://dl.bintray.com/lovell/sharp/) via HTTPS
-and stored locally within `node_modules/sharp`.
-
-## Using a custom tarball
-
-A custom tarball stored on the local filesystem can be used instead.
-Place it in the following location, where `x.y.z` is the libvips version,
-`platform` is the value of `process.platform` and
-`arch` is the value of `process.arch` (plus the version number for ARM).
-
-`node_modules/sharp/packaging/libvips-x.y.z-platform-arch.tar.gz`
-
-For example, for libvips v8.3.3 on an ARMv6 Linux machine, use:
-
-`node_modules/sharp/packaging/libvips-8.3.3-linux-armv6.tar.gz`
-
-Remove any `sharp/lib` and `sharp/include` directories
-before running `npm install` again.
-
-## Creating a tarball
-
-Most people will not need to do this; proceed with caution.
-
-The `packaging` directory contains the top-level [build script](build.sh).
-
-### Linux
-
-One [build script](build/lin.sh) is used to (cross-)compile
-the same shared libraries within multiple containers.
-
-* [x64](linux-x64/Dockerfile)
-* [ARMv6](linux-armv6/Dockerfile)
-* [ARMv7-A](linux-armv7/Dockerfile)
-* [ARMv8-A](linux-armv8/Dockerfile)
-
-The QEMU user mode emulation binaries are required to build for
-the ARMv6 platform as the Debian armhf cross-compiler erroneously
-generates unsupported Thumb 2 instructions.
-
-```sh
-sudo apt-get install qemu-user-static
-```
-
-### Windows
-
-The output of libvips' [build-win64](https://github.com/jcupitt/build-win64)
-"web" target is [post-processed](build/win.sh) within a [container](win32-x64/Dockerfile).
-
-### OS X
-
-See [package-libvips-darwin](https://github.com/lovell/package-libvips-darwin).

packaging/build.sh

@@ -1,48 +0,0 @@
-#!/bin/sh
-set -e
-
-if [ $# -lt 1 ]; then
-  echo
-  echo "Usage: $0 VERSION [PLATFORM]"
-  echo "Build shared libraries for libvips and its dependencies via containers"
-  echo
-  echo "Please specify the libvips VERSION, e.g. 8.3.3"
-  echo
-  echo "Optionally build for only one PLATFORM, defaults to building for all"
-  echo "Possible values for PLATFORM are: win32-x64, linux-x64, linux-armv6,"
-  echo "linux-armv7, linux-armv8"
-  echo
-  exit 1
-fi
-VERSION_VIPS="$1"
-PLATFORM="${2:-all}"
-
-# Is docker available?
-if ! type docker >/dev/null; then
-  echo "Please install docker"
-  exit 1
-fi
-
-# Update base images
-for baseimage in debian:wheezy debian:jessie debian:stretch socialdefect/raspbian-jessie-core; do
-  docker pull $baseimage
-done
-
-# Windows (x64)
-if [ $PLATFORM = "all" ] || [ $PLATFORM = "win32-x64" ]; then
-  echo "Building win32-x64..."
-  docker build -t vips-dev-win32-x64 win32-x64
-  docker run --rm -e "VERSION_VIPS=${VERSION_VIPS}" -v $PWD:/packaging vips-dev-win32-x64 sh -c "/packaging/build/win.sh"
-fi
-
-# Linux (x64, ARMv6, ARMv7, ARMv8)
-for flavour in linux-x64 linux-armv6 linux-armv7 linux-armv8; do
-  if [ $PLATFORM = "all" ] || [ $PLATFORM = $flavour ]; then
-    echo "Building $flavour..."
-    docker build -t vips-dev-$flavour $flavour
-    docker run --rm -e "VERSION_VIPS=${VERSION_VIPS}" -v $PWD:/packaging vips-dev-$flavour sh -c "/packaging/build/lin.sh"
-  fi
-done
-
-# Display checksums
-sha256sum *.tar.gz

packaging/build/lin.sh

@@ -1,256 +0,0 @@
-#!/bin/sh
-set -e
-
-# 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${TARGET}/lib"
-export CFLAGS="${FLAGS}"
-export CXXFLAGS="${FLAGS}"
-
-# Dependency version numbers
-VERSION_ZLIB=1.2.11
-VERSION_FFI=3.2.1
-VERSION_GLIB=2.53.1
-VERSION_XML2=2.9.4
-VERSION_GSF=1.14.41
-VERSION_EXIF=0.6.21
-VERSION_LCMS2=2.8
-VERSION_JPEG=1.5.1
-VERSION_PNG16=1.6.29
-VERSION_WEBP=0.6.0
-VERSION_TIFF=4.0.7
-VERSION_ORC=0.4.26
-VERSION_GDKPIXBUF=2.36.6
-VERSION_FREETYPE=2.8
-VERSION_EXPAT=2.2.0
-VERSION_FONTCONFIG=2.12.1
-VERSION_HARFBUZZ=1.4.6
-VERSION_PIXMAN=0.34.0
-VERSION_CAIRO=1.14.8
-VERSION_PANGO=1.40.5
-VERSION_CROCO=0.6.12
-VERSION_SVG=2.40.17
-VERSION_GIF=5.1.4
-
-# Least out-of-sync Sourceforge mirror
-SOURCEFORGE_MIRROR=netix
-
-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} --uname=linux
-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 ${DEPS}/ffi
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-builddir
-make install-strip
-
-mkdir ${DEPS}/glib
-curl -Ls https://download.gnome.org/sources/glib/2.53/glib-${VERSION_GLIB}.tar.xz | tar xJC ${DEPS}/glib --strip-components=1
-cd ${DEPS}/glib
-echo glib_cv_stack_grows=no >>glib.cache
-echo glib_cv_uscore=no >>glib.cache
-./configure --cache-file=glib.cache --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --with-pcre=internal --disable-libmount
-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 ${DEPS}/xml2
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --without-python --without-debug --without-docbook --without-ftp --without-html --without-legacy \
-  --without-pattern --without-push --without-regexps --without-schemas --without-schematron --with-zlib=${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 ${DEPS}/gsf
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking
-make install-strip
-
-mkdir ${DEPS}/exif
-curl -Ls http://${SOURCEFORGE_MIRROR}.dl.sourceforge.net/project/libexif/libexif/${VERSION_EXIF}/libexif-${VERSION_EXIF}.tar.bz2 | tar xjC ${DEPS}/exif --strip-components=1
-cd ${DEPS}/exif
-autoreconf -fiv
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking
-make install-strip
-
-mkdir ${DEPS}/lcms2
-curl -Ls http://${SOURCEFORGE_MIRROR}.dl.sourceforge.net/project/lcms/lcms/${VERSION_LCMS2}/lcms2-${VERSION_LCMS2}.tar.gz | tar xzC ${DEPS}/lcms2 --strip-components=1
-cd ${DEPS}/lcms2
-# Apply patches for lcms2 vulnerabilities reported since v2.8
-VERSION_LCMS2_GIT_MASTER_SHA=$(curl -Ls https://api.github.com/repos/mm2/Little-CMS/git/refs/heads/master | jq -r '.object.sha' | head -c7)
-curl -Ls https://github.com/mm2/Little-CMS/compare/lcms2.8...master.patch | patch -p1 -t || true
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking
-make install-strip
-
-mkdir ${DEPS}/jpeg
-curl -Ls https://github.com/libjpeg-turbo/libjpeg-turbo/archive/${VERSION_JPEG}.tar.gz | tar xzC ${DEPS}/jpeg --strip-components=1
-cd ${DEPS}/jpeg
-autoreconf -fiv
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --with-jpeg8 --without-turbojpeg
-make install-strip
-
-mkdir ${DEPS}/png16
-curl -Ls http://${SOURCEFORGE_MIRROR}.dl.sourceforge.net/project/libpng/libpng16/${VERSION_PNG16}/libpng-${VERSION_PNG16}.tar.xz | tar xJC ${DEPS}/png16 --strip-components=1
-cd ${DEPS}/png16
-./configure --host=${CHOST} --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 ${DEPS}/webp
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --disable-neon --enable-libwebpmux
-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 ${DEPS}/tiff
-# Apply patches for libtiff vulnerabilities reported since v4.0.7
-VERSION_TIFF_GIT_MASTER_SHA=$(curl -Ls https://api.github.com/repos/vadz/libtiff/git/refs/heads/master | jq -r '.object.sha' | head -c7)
-curl -Ls https://github.com/vadz/libtiff/compare/Release-v4-0-7...master.patch | patch -p1 -t || true
-if [ -n "${CHOST}" ]; then autoreconf -fiv; fi
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-mdi --disable-pixarlog --disable-cxx
-make install-strip
-
-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 ${DEPS}/orc
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking
-make install-strip
-cd ${TARGET}/lib
-rm -rf liborc-test-*
-
-mkdir ${DEPS}/gdkpixbuf
-curl -Ls https://download.gnome.org/sources/gdk-pixbuf/2.36/gdk-pixbuf-${VERSION_GDKPIXBUF}.tar.xz | tar xJC ${DEPS}/gdkpixbuf --strip-components=1
-cd ${DEPS}/gdkpixbuf
-touch gdk-pixbuf/loaders.cache
-LD_LIBRARY_PATH=${TARGET}/lib \
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --disable-introspection --disable-modules --disable-gio-sniffing \
-  --without-libtiff --without-gdiplus --with-included-loaders=png,jpeg
-make install-strip
-
-mkdir ${DEPS}/freetype
-curl -Ls http://${SOURCEFORGE_MIRROR}.dl.sourceforge.net/project/freetype/freetype2/${VERSION_FREETYPE}/freetype-${VERSION_FREETYPE}.tar.gz | tar xzC ${DEPS}/freetype --strip-components=1
-cd ${DEPS}/freetype
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static
-make install
-
-mkdir ${DEPS}/expat
-curl -Ls http://${SOURCEFORGE_MIRROR}.dl.sourceforge.net/project/expat/expat/${VERSION_EXPAT}/expat-${VERSION_EXPAT}.tar.bz2 | tar xjC ${DEPS}/expat --strip-components=1
-cd ${DEPS}/expat
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static
-make install
-
-mkdir ${DEPS}/fontconfig
-curl -Ls https://www.freedesktop.org/software/fontconfig/release/fontconfig-${VERSION_FONTCONFIG}.tar.bz2 | tar xjC ${DEPS}/fontconfig --strip-components=1
-cd ${DEPS}/fontconfig
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --with-expat-includes=${TARGET}/include --with-expat-lib=${TARGET}/lib --sysconfdir=/etc
-make install-strip
-
-mkdir ${DEPS}/harfbuzz
-curl -Ls https://www.freedesktop.org/software/harfbuzz/release/harfbuzz-${VERSION_HARFBUZZ}.tar.bz2 | tar xjC ${DEPS}/harfbuzz --strip-components=1
-cd ${DEPS}/harfbuzz
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking
-make install-strip
-
-mkdir ${DEPS}/pixman
-curl -Ls http://cairographics.org/releases/pixman-${VERSION_PIXMAN}.tar.gz | tar xzC ${DEPS}/pixman --strip-components=1
-cd ${DEPS}/pixman
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-libpng --disable-arm-iwmmxt
-make install-strip
-
-mkdir ${DEPS}/cairo
-curl -Ls http://cairographics.org/releases/cairo-${VERSION_CAIRO}.tar.xz | tar xJC ${DEPS}/cairo --strip-components=1
-cd ${DEPS}/cairo
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --disable-xlib --disable-xcb --disable-quartz --disable-win32 --disable-egl --disable-glx --disable-wgl \
-  --disable-script --disable-ps --disable-gobject --disable-trace --disable-interpreter
-make install-strip
-
-mkdir ${DEPS}/pango
-curl -Ls https://download.gnome.org/sources/pango/1.40/pango-${VERSION_PANGO}.tar.xz | tar xJC ${DEPS}/pango --strip-components=1
-cd ${DEPS}/pango
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking
-make install-strip
-
-mkdir ${DEPS}/croco
-curl -Ls https://download.gnome.org/sources/libcroco/0.6/libcroco-${VERSION_CROCO}.tar.xz | tar xJC ${DEPS}/croco --strip-components=1
-cd ${DEPS}/croco
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking
-make install-strip
-
-mkdir ${DEPS}/svg
-curl -Ls https://download.gnome.org/sources/librsvg/2.40/librsvg-${VERSION_SVG}.tar.xz | tar xJC ${DEPS}/svg --strip-components=1
-cd ${DEPS}/svg
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-introspection --disable-tools --disable-pixbuf-loader
-make install-strip
-
-mkdir ${DEPS}/gif
-curl -Ls http://${SOURCEFORGE_MIRROR}.dl.sourceforge.net/project/giflib/giflib-${VERSION_GIF}.tar.gz | tar xzC ${DEPS}/gif --strip-components=1
-cd ${DEPS}/gif
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking
-make install-strip
-
-mkdir ${DEPS}/vips
-curl -Ls https://github.com/jcupitt/libvips/releases/download/v${VERSION_VIPS}/vips-${VERSION_VIPS}.tar.gz | tar xzC ${DEPS}/vips --strip-components=1
-cd ${DEPS}/vips
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
-  --disable-debug --disable-introspection --without-python --without-fftw \
-  --without-magick --without-pangoft2 --without-ppm --without-analyze --without-radiance \
-  --with-zip-includes=${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 ${TARGET}
-echo "{\n\
-  \"cairo\": \"${VERSION_CAIRO}\",\n\
-  \"croco\": \"${VERSION_CROCO}\",\n\
-  \"exif\": \"${VERSION_EXIF}\",\n\
-  \"expat\": \"${VERSION_EXPAT}\",\n\
-  \"ffi\": \"${VERSION_FFI}\",\n\
-  \"fontconfig\": \"${VERSION_FONTCONFIG}\",\n\
-  \"freetype\": \"${VERSION_FREETYPE}\",\n\
-  \"gdkpixbuf\": \"${VERSION_GDKPIXBUF}\",\n\
-  \"gif\": \"${VERSION_GIF}\",\n\
-  \"glib\": \"${VERSION_GLIB}\",\n\
-  \"gsf\": \"${VERSION_GSF}\",\n\
-  \"harfbuzz\": \"${VERSION_HARFBUZZ}\",\n\
-  \"jpeg\": \"${VERSION_JPEG}\",\n\
-  \"lcms\": \"${VERSION_LCMS2}-${VERSION_LCMS2_GIT_MASTER_SHA}\",\n\
-  \"orc\": \"${VERSION_ORC}\",\n\
-  \"pango\": \"${VERSION_PANGO}\",\n\
-  \"pixman\": \"${VERSION_PIXMAN}\",\n\
-  \"png\": \"${VERSION_PNG16}\",\n\
-  \"svg\": \"${VERSION_SVG}\",\n\
-  \"tiff\": \"${VERSION_TIFF}-${VERSION_TIFF_GIT_MASTER_SHA}\",\n\
-  \"vips\": \"${VERSION_VIPS}\",\n\
-  \"webp\": \"${VERSION_WEBP}\",\n\
-  \"xml\": \"${VERSION_XML2}\",\n\
-  \"zlib\": \"${VERSION_ZLIB}\"\n\
-}" >lib/versions.json
-
-# Create .tar.gz
-tar czf /packaging/libvips-${VERSION_VIPS}-${PLATFORM}.tar.gz include lib
-advdef --recompress --shrink-insane /packaging/libvips-${VERSION_VIPS}-${PLATFORM}.tar.gz

packaging/build/win.sh

@@ -1,19 +0,0 @@
-#!/bin/sh
-set -e
-
-# Fetch and unzip
-mkdir /vips
-cd /vips
-curl -L -O https://github.com/lovell/build-win64/releases/download/v${VERSION_VIPS}/vips-dev-w64-web-${VERSION_VIPS}.zip
-unzip vips-dev-w64-web-${VERSION_VIPS}.zip
-
-# Clean and zip
-cd /vips/vips-dev-8.5
-rm bin/libvipsCC-42.dll bin/libvips-cpp-42.dll bin/libgsf-win32-1-114.dll
-cp bin/*.dll lib/
-cp -r lib64/* lib/
-
-echo "Creating tarball"
-tar czf /packaging/libvips-${VERSION_VIPS}-${PLATFORM}.tar.gz include lib/glib-2.0 lib/libvips.lib lib/libglib-2.0.lib lib/libgobject-2.0.lib lib/*.dll
-echo "Shrinking tarball"
-advdef --recompress --shrink-insane /packaging/libvips-${VERSION_VIPS}-${PLATFORM}.tar.gz

packaging/linux-armv6/Dockerfile

@@ -1,15 +0,0 @@
-FROM socialdefect/raspbian-jessie-core
-MAINTAINER Lovell Fuller <npm@lovell.info>
-
-# Create Rasbian-based container suitable for compiling Linux ARMv6 binaries
-# Requires the QEMU user mode emulation binaries on the host machine
-
-# Build dependencies
-RUN \
-  apt-get update && \
-  apt-get install -y build-essential curl autoconf libtool nasm gtk-doc-tools texinfo advancecomp libglib2.0-dev jq
-
-# Compiler settings
-ENV \
-  PLATFORM=linux-armv6 \
-  FLAGS="-Os"

packaging/linux-armv7/Dockerfile

@@ -1,20 +0,0 @@
-FROM debian:jessie
-MAINTAINER Lovell Fuller <npm@lovell.info>
-
-# Create Debian-based container suitable for cross-compiling Linux ARMv7-A binaries
-
-# Build dependencies
-RUN \
-  apt-get update && \
-  apt-get install -y curl && \
-  echo "deb http://emdebian.org/tools/debian/ jessie main" | tee /etc/apt/sources.list.d/crosstools.list && \
-  curl http://emdebian.org/tools/debian/emdebian-toolchain-archive.key | apt-key add - && \
-  dpkg --add-architecture armhf && \
-  apt-get update && \
-  apt-get install -y crossbuild-essential-armhf autoconf libtool nasm gtk-doc-tools texinfo advancecomp libglib2.0-dev jq
-
-# Compiler settings
-ENV \
-  PLATFORM=linux-armv7 \
-  CHOST=arm-linux-gnueabihf \
-  FLAGS="-marm -march=armv7-a -mfpu=neon-vfpv4 -mfloat-abi=hard -Os"

packaging/linux-armv8/Dockerfile

@@ -1,18 +0,0 @@
-FROM debian:stretch
-MAINTAINER Lovell Fuller <npm@lovell.info>
-
-# Create Debian-based container suitable for cross-compiling Linux ARMv8-A binaries
-
-# Build dependencies
-RUN \
-  apt-get update && \
-  apt-get install -y curl && \
-  dpkg --add-architecture arm64 && \
-  apt-get update && \
-  apt-get install -y crossbuild-essential-arm64 autoconf libtool nasm gtk-doc-tools texinfo advancecomp libglib2.0-dev jq gettext intltool autopoint
-
-# Compiler settings
-ENV \
-  PLATFORM=linux-armv8 \
-  CHOST=aarch64-linux-gnu \
-  FLAGS="-march=armv8-a -Os -D_GLIBCXX_USE_CXX11_ABI=0"

packaging/linux-x64/Dockerfile

@@ -1,16 +0,0 @@
-FROM debian:wheezy
-MAINTAINER Lovell Fuller <npm@lovell.info>
-
-# Create Debian-based container suitable for building Linux x64 binaries
-
-# Build dependencies
-RUN \
-  echo "deb http://ftp.debian.org/debian wheezy-backports main" | tee /etc/apt/sources.list.d/wheezy-backports.list && \
-  apt-get update && \
-  apt-get install -y build-essential autoconf libtool nasm gtk-doc-tools texinfo advancecomp && \
-  apt-get -t wheezy-backports install -y jq
-
-# Compiler settings
-ENV \
-  PLATFORM="linux-x64" \
-  FLAGS="-O3"

packaging/test-linux-arm.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 $IP"
-  exit 1
-fi
-
-if ! type sshpass >/dev/null; then
-  echo "Please install sshpass"
-  exit 1
-fi
-
-export SSHPASS=hypriot
-
-echo "Copying sharp source to device"
-sshpass -e scp -o PreferredAuthentications=password -r ../../sharp pirate@${IP}:/home/pirate/sharp
-
-echo "Compile and test within container"
-sshpass -e ssh -o PreferredAuthentications=password -t pirate@${IP} "docker run --rm -v \${PWD}/sharp:/s hypriot/rpi-node:6 sh -c 'cd /s && npm install --unsafe-perm && npm test'"

packaging/test-linux-x64.sh

@@ -1,36 +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 14.04, 16.04
-for dist in debian:jessie debian:stretch ubuntu:trusty ubuntu:xenial; do
-  echo "Testing $dist..."
-  docker pull $dist
-  if docker run -i -t --rm -v $PWD:/v $dist >packaging/$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 7
-echo "Testing centos7..."
-docker pull centos:7
-if docker run -i -t --rm -v $PWD:/v centos:7 >packaging/centos7.log 2>&1 sh -c "cd /v; ./packaging/test/centos.sh; $test";
-then echo "centos7 OK"
-else echo "centos7 fail" && cat packaging/centos7.log
-fi
-
-# Archlinux latest
-echo "Testing archlinux..."
-docker pull pritunl/archlinux:latest
-if docker run -i -t --rm -v $PWD:/v pritunl/archlinux:latest >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

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/centos.sh

@@ -1,4 +0,0 @@
-#!/bin/sh
-
-curl -sL https://rpm.nodesource.com/setup_6.x | bash -
-yum install -y gcc-c++ make nodejs

packaging/test/debian.sh

@@ -1,6 +0,0 @@
-#!/bin/sh
-
-apt-get update
-apt-get install -y build-essential python pkg-config curl
-curl -sL https://deb.nodesource.com/setup_6.x | bash -
-apt-get install -y nodejs

packaging/win32-x64/Dockerfile

@@ -1,8 +0,0 @@
-FROM debian:stretch
-MAINTAINER Lovell Fuller <npm@lovell.info>
-
-# Create Debian-based container suitable for post-processing Windows x64 binaries
-
-RUN apt-get update && apt-get install -y curl zip advancecomp
-
-ENV PLATFORM=win32-x64

src/common.cc

@@ -40,7 +40,7 @@ namespace sharp {
 
   // 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
+    v8::Handle<v8::Object> input, std::vector<v8::Local<v8::Object>> &buffersToPersist
   ) {
     Nan::HandleScope();
     InputDescriptor *descriptor = new InputDescriptor;
@@ -52,6 +52,7 @@ namespace sharp {
       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<uint32_t>(input, "density");
@@ -62,6 +63,10 @@ namespace sharp {
       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");
@@ -219,13 +224,18 @@ namespace sharp {
         imageType = DetermineImageType(descriptor->buffer, descriptor->bufferLength);
         if (imageType != ImageType::UNKNOWN) {
           try {
-            vips::VOption *option = VImage::option()->set("access", accessMethod);
+            vips::VOption *option = VImage::option()
+              ->set("access", accessMethod)
+              ->set("fail", descriptor->failOnError);
             if (imageType == ImageType::SVG || imageType == ImageType::PDF) {
               option->set("dpi", static_cast<double>(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);
@@ -256,13 +266,18 @@ namespace sharp {
         imageType = DetermineImageType(descriptor->file.data());
         if (imageType != ImageType::UNKNOWN) {
           try {
-            vips::VOption *option = VImage::option()->set("access", accessMethod);
+            vips::VOption *option = VImage::option()
+              ->set("access", accessMethod)
+              ->set("fail", descriptor->failOnError);
             if (imageType == ImageType::SVG || imageType == ImageType::PDF) {
               option->set("dpi", static_cast<double>(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);
@@ -404,7 +419,62 @@ namespace sharp {
 
   /*
     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) {

src/common.h

@@ -25,17 +25,17 @@
 
 // Verify platform and compiler compatibility
 
-#if (VIPS_MAJOR_VERSION < 8 || (VIPS_MAJOR_VERSION == 8 && VIPS_MINOR_VERSION < 5))
-#error libvips version 8.5.x required - see sharp.dimens.io/page/install
+#if (VIPS_MAJOR_VERSION < 8 || (VIPS_MAJOR_VERSION == 8 && VIPS_MINOR_VERSION < 6))
+#error libvips version 8.6.1+ 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.dimens.io/page/install#prerequisites
+#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.dimens.io/page/install#prerequisites
+#error clang version 3.0+ is required for C++11 features - see sharp.pixelplumbing.com/page/install#prerequisites
 #endif
 #endif
 
@@ -47,11 +47,13 @@ namespace sharp {
     std::string name;
     std::string file;
     char *buffer;
+    bool failOnError;
     size_t bufferLength;
     int density;
     int rawChannels;
     int rawWidth;
     int rawHeight;
+    int page;
     int createChannels;
     int createWidth;
     int createHeight;
@@ -59,11 +61,13 @@ namespace sharp {
 
     InputDescriptor():
       buffer(nullptr),
+      failOnError(FALSE),
       bufferLength(0),
       density(72),
       rawChannels(0),
       rawWidth(0),
       rawHeight(0),
+      page(0),
       createChannels(0),
       createWidth(0),
       createHeight(0) {
@@ -89,7 +93,7 @@ namespace sharp {
 
   // 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);
+    v8::Handle<v8::Object> input, std::vector<v8::Local<v8::Object>> &buffersToPersist);
 
   enum class ImageType {
     JPEG,
@@ -204,6 +208,13 @@ namespace sharp {
   */
   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.

src/libvips/cplusplus/VImage.cpp

@@ -205,6 +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 )
@@ -465,8 +489,7 @@ VImage::call_option_string( const char *operation_name,
 		operation_name );
 
 	if( !(operation = vips_operation_new( operation_name )) ) {
-		if( options )
-			delete options;
+		delete options;
 		throw( VError() ); 
 	}
 
@@ -565,34 +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 + 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 ) 
 {
@@ -693,10 +688,21 @@ VImage::bandsplit( VOption *options )
 VImage 
 VImage::bandjoin( VImage other, VOption *options )
 {
-    VImage v[2] = { *this, other }; 
-    std::vector<VImage> vec( v, v + VIPS_NUMBER( v ) );
+	VImage v[2] = { *this, other }; 
+	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 )
+{
+	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> 

src/libvips/cplusplus/vips-operators.cpp

@@ -1,5 +1,5 @@
 // bodies for vips operations
-// Mon 13 Mar 13:22:17 GMT 2017
+// Sun 26 Nov 17:44:23 GMT 2017
 // this file is generated automatically, do not edit!
 
 void VImage::system( char * cmd_format , VOption *options )
@@ -487,6 +487,21 @@ std::vector<double> VImage::getpoint( int x , int y , VOption *options )
     return( out_array );
 }
 
+int VImage::find_trim( int * top , int * width , int * height , VOption *options )
+{
+    int left;
+
+    call( "find_trim" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "left", &left ) ->
+            set( "top", top ) ->
+            set( "width", width ) ->
+            set( "height", height ) );
+
+    return( left );
+}
+
 VImage VImage::copy( VOption *options )
 {
     VImage out;
@@ -563,6 +578,21 @@ VImage VImage::embed( int x , int y , int width , int height , VOption *options
     return( out );
 }
 
+VImage VImage::gravity( VipsCompassDirection direction , int width , int height , VOption *options )
+{
+    VImage out;
+
+    call( "gravity" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "out", &out ) ->
+            set( "direction", direction ) ->
+            set( "width", width ) ->
+            set( "height", height ) );
+
+    return( out );
+}
+
 VImage VImage::flip( VipsDirection direction , VOption *options )
 {
     VImage out;
@@ -988,6 +1018,19 @@ VImage VImage::gamma( VOption *options )
     return( out );
 }
 
+VImage VImage::composite( std::vector<VImage> in , std::vector<int> mode , VOption *options )
+{
+    VImage out;
+
+    call( "composite" ,
+        (options ? options : VImage::option()) ->
+            set( "in", in ) ->
+            set( "out", &out ) ->
+            set( "mode", mode ) );
+
+    return( out );
+}
+
 VImage VImage::black( int width , int height , VOption *options )
 {
     VImage out;
@@ -1904,6 +1947,19 @@ VImage VImage::thumbnail_buffer( VipsBlob * buffer , int width , VOption *option
     return( out );
 }
 
+VImage VImage::thumbnail_image( int width , VOption *options )
+{
+    VImage out;
+
+    call( "thumbnail_image" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "out", &out ) ->
+            set( "width", width ) );
+
+    return( out );
+}
+
 VImage VImage::mapim( VImage index , VOption *options )
 {
     VImage out;
@@ -2822,6 +2878,18 @@ VImage VImage::labelregions( VOption *options )
     return( mask );
 }
 
+VImage VImage::fill_nearest( VOption *options )
+{
+    VImage out;
+
+    call( "fill_nearest" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "out", &out ) );
+
+    return( out );
+}
+
 void VImage::draw_rect( std::vector<double> ink , int left , int top , int width , int height , VOption *options )
 {
     call( "draw_rect" ,

src/metadata.cc

@@ -27,7 +27,8 @@ class MetadataWorker : public Nan::AsyncWorker {
   MetadataWorker(
     Nan::Callback *callback, MetadataBaton *baton, Nan::Callback *debuglog,
     std::vector<v8::Local<v8::Object>> const buffersToPersist) :
-    Nan::AsyncWorker(callback), baton(baton), debuglog(debuglog),
+    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,
@@ -81,6 +82,22 @@ class MetadataWorker : public Nan::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
@@ -123,6 +140,16 @@ class MetadataWorker : public Nan::AsyncWorker {
           New("icc").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;
     }
 
@@ -139,12 +166,12 @@ class MetadataWorker : public Nan::AsyncWorker {
     std::string warning = sharp::VipsWarningPop();
     while (!warning.empty()) {
       v8::Local<v8::Value> message[1] = { New(warning).ToLocalChecked() };
-      debuglog->Call(1, message);
+      debuglog->Call(1, message, async_resource);
       warning = sharp::VipsWarningPop();
     }
 
     // Return to JavaScript
-    callback->Call(2, argv);
+    callback->Call(2, argv, async_resource);
   }
 
  private:

src/metadata.h

@@ -38,6 +38,10 @@ struct MetadataBaton {
   size_t exifLength;
   char *icc;
   size_t iccLength;
+  char *iptc;
+  size_t iptcLength;
+  char *xmp;
+  size_t xmpLength;
   std::string err;
 
   MetadataBaton():
@@ -52,7 +56,11 @@ struct MetadataBaton {
     exif(nullptr),
     exifLength(0),
     icc(nullptr),
-    iccLength(0) {}
+    iccLength(0),
+    iptc(nullptr),
+    iptcLength(0),
+    xmp(nullptr),
+    xmpLength(0) {}
 };
 
 NAN_METHOD(metadata);

src/operations.cc

@@ -28,6 +28,16 @@ using vips::VError;
 
 namespace sharp {
 
+  /*
+    Removes alpha channel, if any.
+  */
+  VImage RemoveAlpha(VImage image) {
+    if (HasAlpha(image)) {
+      image = image.extract_band(0, VImage::option()->set("n", image.bands() - 1));
+    }
+    return image;
+  }
+
   /*
     Composite overlayImage over image at given position
     Assumes alpha channels are already premultiplied and will be unpremultiplied after
@@ -152,6 +162,33 @@ namespace sharp {
     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.
    */
@@ -196,10 +233,8 @@ 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));
     }
@@ -267,23 +302,6 @@ namespace sharp {
     }
   }
 
-  /*
-    Insert a tile cache to prevent over-computation of any previous operations in the pipeline
-  */
-  VImage TileCache(VImage image, double const factor) {
-    int tile_width;
-    int tile_height;
-    int scanline_count;
-    vips_get_tile_size(image.get_image(), &tile_width, &tile_height, &scanline_count);
-    double const need_lines = 1.2 * scanline_count / factor;
-    return image.tilecache(VImage::option()
-      ->set("tile_width", image.width())
-      ->set("tile_height", 10)
-      ->set("max_tiles", static_cast<int>(round(1.0 + need_lines / 10.0)))
-      ->set("access", VIPS_ACCESS_SEQUENTIAL)
-      ->set("threaded", TRUE));
-  }
-
   VImage Threshold(VImage image, double const threshold, bool const thresholdGrayscale) {
     if (!thresholdGrayscale) {
       return image >= threshold;
@@ -358,4 +376,16 @@ namespace sharp {
     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

@@ -25,6 +25,11 @@ using vips::VImage;
 
 namespace sharp {
 
+  /*
+    Removes alpha channel, if any.
+  */
+  VImage RemoveAlpha(VImage image);
+
   /*
     Alpha composite src over dst with given gravity.
     Assumes alpha channels are already premultiplied and will be unpremultiplied after.
@@ -46,6 +51,11 @@ namespace sharp {
   */
   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.
    */
@@ -72,11 +82,6 @@ namespace sharp {
    */
   VImage Sharpen(VImage image, double const sigma, double const flat, double const jagged);
 
-  /*
-    Insert a tile cache to prevent over-computation of any previous operations in the pipeline
-  */
-  VImage TileCache(VImage image, double const factor);
-
   /*
     Threshold an image
   */
@@ -97,6 +102,11 @@ namespace sharp {
   */
   VImage Trim(VImage image, int const tolerance);
 
+  /*
+   * Linear adjustment (a * in + b)
+   */
+  VImage Linear(VImage image, double const a, double const b);
+
 }  // namespace sharp
 
 #endif  // SRC_OPERATIONS_H_

src/pipeline.cc

@@ -35,7 +35,8 @@ class PipelineWorker : public Nan::AsyncWorker {
   PipelineWorker(
     Nan::Callback *callback, PipelineBaton *baton, Nan::Callback *debuglog, Nan::Callback *queueListener,
     std::vector<v8::Local<v8::Object>> const buffersToPersist) :
-    Nan::AsyncWorker(callback), baton(baton), debuglog(debuglog), queueListener(queueListener),
+    Nan::AsyncWorker(callback, "sharp:PipelineWorker"),
+    baton(baton), debuglog(debuglog), queueListener(queueListener),
     buffersToPersist(buffersToPersist) {
     // Protect Buffer objects from GC, keyed on index
     std::accumulate(buffersToPersist.begin(), buffersToPersist.end(), 0,
@@ -222,20 +223,27 @@ class PipelineWorker : public Nan::AsyncWorker {
       // If integral x and y shrink are equal, try to use shrink-on-load for JPEG and WebP,
       // but not when applying gamma correction, pre-resize extract or trim
       int shrink_on_load = 1;
+
+      int shrink_on_load_factor = 1;
+      // Leave at least a factor of two for the final resize step, when fastShrinkOnLoad: false
+      // for more consistent results and avoid occasional small image shifting
+      if (!baton->fastShrinkOnLoad) {
+        shrink_on_load_factor = 2;
+      }
       if (
-        xshrink == yshrink && xshrink >= 2 &&
+        xshrink == yshrink && xshrink >= 2 * shrink_on_load_factor &&
         (inputImageType == ImageType::JPEG || inputImageType == ImageType::WEBP) &&
         baton->gamma == 0 && baton->topOffsetPre == -1 && baton->trimTolerance == 0
       ) {
-        if (xshrink >= 8) {
+        if (xshrink >= 8 * shrink_on_load_factor) {
           xfactor = xfactor / 8;
           yfactor = yfactor / 8;
           shrink_on_load = 8;
-        } else if (xshrink >= 4) {
+        } else if (xshrink >= 4 * shrink_on_load_factor) {
           xfactor = xfactor / 4;
           yfactor = yfactor / 4;
           shrink_on_load = 4;
-        } else if (xshrink >= 2) {
+        } else if (xshrink >= 2 * shrink_on_load_factor) {
           xfactor = xfactor / 2;
           yfactor = yfactor / 2;
           shrink_on_load = 2;
@@ -249,7 +257,10 @@ class PipelineWorker : public Nan::AsyncWorker {
       }
       if (shrink_on_load > 1) {
         // Reload input using shrink-on-load
-        vips::VOption *option = VImage::option()->set("shrink", shrink_on_load);
+        vips::VOption *option = VImage::option()
+          ->set("access", baton->accessMethod)
+          ->set("shrink", shrink_on_load)
+          ->set("fail", baton->input->failOnError);
         if (baton->input->buffer != nullptr) {
           VipsBlob *blob = vips_blob_new(nullptr, baton->input->buffer, baton->input->bufferLength);
           if (inputImageType == ImageType::JPEG) {
@@ -270,32 +281,17 @@ class PipelineWorker : public Nan::AsyncWorker {
           }
         }
         // Recalculate integral shrink and double residual
-        int shrunkOnLoadWidth = image.width();
-        int shrunkOnLoadHeight = image.height();
+        int const shrunkOnLoadWidth = image.width();
+        int const shrunkOnLoadHeight = image.height();
         if (!baton->rotateBeforePreExtract &&
           (rotation == VIPS_ANGLE_D90 || rotation == VIPS_ANGLE_D270)) {
-          // Swap input output width and height when rotating by 90 or 270 degrees
-          std::swap(shrunkOnLoadWidth, shrunkOnLoadHeight);
+          // Swap when rotating by 90 or 270 degrees
+          xfactor = static_cast<double>(shrunkOnLoadWidth) / static_cast<double>(targetResizeHeight);
+          yfactor = static_cast<double>(shrunkOnLoadHeight) / static_cast<double>(targetResizeWidth);
+        } else {
+          xfactor = static_cast<double>(shrunkOnLoadWidth) / static_cast<double>(targetResizeWidth);
+          yfactor = static_cast<double>(shrunkOnLoadHeight) / static_cast<double>(targetResizeHeight);
         }
-        xfactor = static_cast<double>(shrunkOnLoadWidth) / static_cast<double>(targetResizeWidth);
-        yfactor = static_cast<double>(shrunkOnLoadHeight) / static_cast<double>(targetResizeHeight);
-        xshrink = std::max(1, static_cast<int>(floor(xfactor)));
-        yshrink = std::max(1, static_cast<int>(floor(yfactor)));
-        xresidual = static_cast<double>(xshrink) / xfactor;
-        yresidual = static_cast<double>(yshrink) / yfactor;
-        if (
-          !baton->rotateBeforePreExtract &&
-          (rotation == VIPS_ANGLE_D90 || rotation == VIPS_ANGLE_D270)
-        ) {
-          std::swap(xresidual, yresidual);
-        }
-      }
-      // Help ensure a final kernel-based reduction to prevent shrink aliasing
-      if (xshrink > 1 && yshrink > 1 && (xresidual == 1.0 || yresidual == 1.0)) {
-        xshrink = xshrink / 2;
-        yshrink = yshrink / 2;
-        xresidual = static_cast<double>(xshrink) / xfactor;
-        yresidual = static_cast<double>(yshrink) / yfactor;
       }
 
       // Ensure we're using a device-independent colour space
@@ -361,13 +357,14 @@ class PipelineWorker : public Nan::AsyncWorker {
         }
       }
 
-      bool const shouldShrink = xshrink > 1 || yshrink > 1;
-      bool const shouldReduce = xresidual != 1.0 || yresidual != 1.0;
+      bool const shouldResize = xfactor != 1.0 || yfactor != 1.0;
       bool const shouldBlur = baton->blurSigma != 0.0;
       bool const shouldConv = baton->convKernelWidth * baton->convKernelHeight > 0;
       bool const shouldSharpen = baton->sharpenSigma != 0.0;
+      bool const shouldApplyMedian = baton->medianSize > 0;
+
       bool const shouldPremultiplyAlpha = HasAlpha(image) &&
-        (shouldShrink || shouldReduce || shouldBlur || shouldConv || shouldSharpen || shouldOverlayWithAlpha);
+        (shouldResize || shouldBlur || shouldConv || shouldSharpen || shouldOverlayWithAlpha);
 
       // Premultiply image alpha channel before all transformations to avoid
       // dark fringing around bright pixels
@@ -376,79 +373,19 @@ class PipelineWorker : public Nan::AsyncWorker {
         image = image.premultiply();
       }
 
-      // Fast, integral box-shrink
-      if (shouldShrink) {
-        if (yshrink > 1) {
-          image = image.shrinkv(yshrink);
-        }
-        if (xshrink > 1) {
-          image = image.shrinkh(xshrink);
-        }
-        // Recalculate residual float based on dimensions of required vs shrunk images
-        int shrunkWidth = image.width();
-        int shrunkHeight = image.height();
-        if (!baton->rotateBeforePreExtract &&
-          (rotation == VIPS_ANGLE_D90 || rotation == VIPS_ANGLE_D270)) {
-          // Swap input output width and height when rotating by 90 or 270 degrees
-          std::swap(shrunkWidth, shrunkHeight);
-        }
-        xresidual = static_cast<double>(targetResizeWidth) / static_cast<double>(shrunkWidth);
-        yresidual = static_cast<double>(targetResizeHeight) / static_cast<double>(shrunkHeight);
+      // Resize
+      if (shouldResize) {
+        VipsKernel kernel = static_cast<VipsKernel>(
+          vips_enum_from_nick(nullptr, VIPS_TYPE_KERNEL, baton->kernel.data()));
         if (
-          !baton->rotateBeforePreExtract &&
-          (rotation == VIPS_ANGLE_D90 || rotation == VIPS_ANGLE_D270)
+          kernel != VIPS_KERNEL_NEAREST && kernel != VIPS_KERNEL_CUBIC && kernel != VIPS_KERNEL_LANCZOS2 &&
+          kernel != VIPS_KERNEL_LANCZOS3
         ) {
-          std::swap(xresidual, yresidual);
-        }
-      }
-
-      // Use affine increase or kernel reduce with the remaining float part
-      if (xresidual != 1.0 || yresidual != 1.0) {
-        // Insert tile cache to prevent over-computation of previous operations
-        if (baton->accessMethod == VIPS_ACCESS_SEQUENTIAL) {
-          image = sharp::TileCache(image, yresidual);
-        }
-        // Perform kernel-based reduction
-        if (yresidual < 1.0 || xresidual < 1.0) {
-          VipsKernel kernel = static_cast<VipsKernel>(
-            vips_enum_from_nick(nullptr, VIPS_TYPE_KERNEL, baton->kernel.data()));
-          if (
-            kernel != VIPS_KERNEL_NEAREST && kernel != VIPS_KERNEL_CUBIC && kernel != VIPS_KERNEL_LANCZOS2 &&
-            kernel != VIPS_KERNEL_LANCZOS3
-          ) {
-            throw vips::VError("Unknown kernel");
-          }
-          if (yresidual < 1.0) {
-            image = image.reducev(1.0 / yresidual, VImage::option()
-              ->set("kernel", kernel)
-              ->set("centre", baton->centreSampling));
-          }
-          if (xresidual < 1.0) {
-            image = image.reduceh(1.0 / xresidual, VImage::option()
-              ->set("kernel", kernel)
-              ->set("centre", baton->centreSampling));
-          }
-        }
-        // Perform enlargement
-        if (yresidual > 1.0 || xresidual > 1.0) {
-          if (trunc(xresidual) == xresidual && trunc(yresidual) == yresidual && baton->interpolator == "nearest") {
-            // Fast, integral nearest neighbour enlargement
-            image = image.zoom(static_cast<int>(xresidual), static_cast<int>(yresidual));
-          } else {
-            // Floating point affine transformation
-            vips::VInterpolate interpolator = vips::VInterpolate::new_from_name(baton->interpolator.data());
-            if (yresidual > 1.0 && xresidual > 1.0) {
-              image = image.affine({xresidual, 0.0, 0.0, yresidual}, VImage::option()
-                ->set("interpolate", interpolator));
-            } else if (yresidual > 1.0) {
-              image = image.affine({1.0, 0.0, 0.0, yresidual}, VImage::option()
-                ->set("interpolate", interpolator));
-            } else if (xresidual > 1.0) {
-              image = image.affine({xresidual, 0.0, 0.0, 1.0}, VImage::option()
-                ->set("interpolate", interpolator));
-            }
-          }
+          throw vips::VError("Unknown kernel");
         }
+        image = image.resize(1.0 / xfactor, VImage::option()
+          ->set("vscale", 1.0 / yfactor)
+          ->set("kernel", kernel));
       }
 
       // Rotate
@@ -513,13 +450,29 @@ class PipelineWorker : public Nan::AsyncWorker {
             image = image.bandjoin(
               VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier));
           }
+
           // Embed
-          int left = static_cast<int>(round((baton->width - image.width()) / 2));
-          int top = static_cast<int>(round((baton->height - image.height()) / 2));
-          image = image.embed(left, top, baton->width, baton->height, VImage::option()
+
+          // Calculate where to position the embeded image if gravity specified, else center.
+          int left;
+          int top;
+
+          left = static_cast<int>(round((baton->width - image.width()) / 2));
+          top = static_cast<int>(round((baton->height - image.height()) / 2));
+
+          int width = std::max(image.width(), baton->width);
+          int height = std::max(image.height(), baton->height);
+          std::tie(left, top) = sharp::CalculateEmbedPosition(
+            image.width(), image.height(), baton->width, baton->height, baton->embed);
+
+          image = image.embed(left, top, width, height, VImage::option()
             ->set("extend", VIPS_EXTEND_BACKGROUND)
             ->set("background", background));
-        } else if (baton->canvas != Canvas::IGNORE_ASPECT) {
+
+        } else if (
+          baton->canvas != Canvas::IGNORE_ASPECT &&
+          (image.width() > baton->width || image.height() > baton->height)
+        ) {
           // Crop/max/min
           if (baton->crop < 9) {
             // Gravity-based crop
@@ -532,8 +485,20 @@ class PipelineWorker : public Nan::AsyncWorker {
             image = image.extract_area(left, top, width, height);
           } else {
             // Attention-based or Entropy-based crop
+            if (baton->width > image.width()) {
+              baton->width = image.width();
+            }
+            if (baton->height > image.height()) {
+              baton->height = image.height();
+            }
+            image = image.tilecache(VImage::option()
+              ->set("access", baton->accessMethod)
+              ->set("threaded", TRUE));
             image = image.smartcrop(baton->width, baton->height, VImage::option()
               ->set("interesting", baton->crop == 16 ? VIPS_INTERESTING_ENTROPY : VIPS_INTERESTING_ATTENTION));
+            baton->hasCropOffset = true;
+            baton->cropOffsetLeft = static_cast<int>(image.xoffset());
+            baton->cropOffsetTop = static_cast<int>(image.yoffset());
           }
         }
       }
@@ -582,7 +547,10 @@ class PipelineWorker : public Nan::AsyncWorker {
         image = image.embed(baton->extendLeft, baton->extendTop, baton->width, baton->height,
           VImage::option()->set("extend", VIPS_EXTEND_BACKGROUND)->set("background", background));
       }
-
+      // Median - must happen before blurring, due to the utility of blurring after thresholding
+      if (shouldApplyMedian) {
+        image = image.median(baton->medianSize);
+      }
       // Threshold - must happen before blurring, due to the utility of blurring after thresholding
       if (baton->threshold != 0) {
         image = sharp::Threshold(image, baton->threshold, baton->thresholdGrayscale);
@@ -692,6 +660,11 @@ class PipelineWorker : public Nan::AsyncWorker {
         image = sharp::Gamma(image, baton->gamma);
       }
 
+      // Linear adjustment (a * in + b)
+      if (baton->linearA != 1.0 || baton->linearB != 0.0) {
+        image = sharp::Linear(image, baton->linearA, baton->linearB);
+      }
+
       // Apply normalisation - stretch luminance to cover full dynamic range
       if (baton->normalise) {
         image = sharp::Normalise(image);
@@ -710,14 +683,30 @@ class PipelineWorker : public Nan::AsyncWorker {
         image = sharp::Bandbool(image, baton->bandBoolOp);
       }
 
+      // Tint the image
+      if (baton->tintA < 128.0 || baton->tintB < 128.0) {
+        image = sharp::Tint(image, baton->tintA, baton->tintB);
+      }
+
       // Extract an image channel (aka vips band)
       if (baton->extractChannel > -1) {
         if (baton->extractChannel >= image.bands()) {
           (baton->err).append("Cannot extract channel from image. Too few channels in image.");
           return Error();
         }
-        image = image.extract_band(baton->extractChannel);
+        VipsInterpretation const interpretation = sharp::Is16Bit(image.interpretation())
+          ? VIPS_INTERPRETATION_GREY16
+          : VIPS_INTERPRETATION_B_W;
+        image = image
+          .extract_band(baton->extractChannel)
+          .copy(VImage::option()->set("interpretation", interpretation));
       }
+
+      // Remove alpha channel, if any
+      if (baton->removeAlpha) {
+        image = sharp::RemoveAlpha(image);
+      }
+
       // Convert image to sRGB, if not already
       if (sharp::Is16Bit(image.interpretation())) {
         image = image.cast(VIPS_FORMAT_USHORT);
@@ -753,9 +742,10 @@ class PipelineWorker : public Nan::AsyncWorker {
             ->set("interlace", baton->jpegProgressive)
             ->set("no_subsample", baton->jpegChromaSubsampling == "4:4:4")
             ->set("trellis_quant", baton->jpegTrellisQuantisation)
+            ->set("quant_table", baton->jpegQuantisationTable)
             ->set("overshoot_deringing", baton->jpegOvershootDeringing)
             ->set("optimize_scans", baton->jpegOptimiseScans)
-            ->set("optimize_coding", TRUE)));
+            ->set("optimize_coding", baton->jpegOptimiseCoding)));
           baton->bufferOut = static_cast<char*>(area->data);
           baton->bufferOutLength = area->length;
           area->free_fn = nullptr;
@@ -856,9 +846,10 @@ class PipelineWorker : public Nan::AsyncWorker {
         bool const isDz = sharp::IsDz(baton->fileOut);
         bool const isDzZip = sharp::IsDzZip(baton->fileOut);
         bool const isV = sharp::IsV(baton->fileOut);
-        bool const matchInput = baton->formatOut == "input" &&
-          !(isJpeg || isPng || isWebp || isTiff || isDz || isDzZip || isV);
-        if (baton->formatOut == "jpeg" || isJpeg || (matchInput && inputImageType == ImageType::JPEG)) {
+        bool const mightMatchInput = baton->formatOut == "input";
+        bool const willMatchInput = mightMatchInput && !(isJpeg || isPng || isWebp || isTiff || isDz || isDzZip || isV);
+        if (baton->formatOut == "jpeg" || (mightMatchInput && isJpeg) ||
+          (willMatchInput && inputImageType == ImageType::JPEG)) {
           // Write JPEG to file
           sharp::AssertImageTypeDimensions(image, ImageType::JPEG);
           image.jpegsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
@@ -867,12 +858,13 @@ class PipelineWorker : public Nan::AsyncWorker {
             ->set("interlace", baton->jpegProgressive)
             ->set("no_subsample", baton->jpegChromaSubsampling == "4:4:4")
             ->set("trellis_quant", baton->jpegTrellisQuantisation)
+            ->set("quant_table", baton->jpegQuantisationTable)
             ->set("overshoot_deringing", baton->jpegOvershootDeringing)
             ->set("optimize_scans", baton->jpegOptimiseScans)
-            ->set("optimize_coding", TRUE));
+            ->set("optimize_coding", baton->jpegOptimiseCoding));
           baton->formatOut = "jpeg";
           baton->channels = std::min(baton->channels, 3);
-        } else if (baton->formatOut == "png" || isPng || (matchInput &&
+        } else if (baton->formatOut == "png" || (mightMatchInput && isPng) || (willMatchInput &&
           (inputImageType == ImageType::PNG || inputImageType == ImageType::GIF || inputImageType == ImageType::SVG))) {
           // Write PNG to file
           sharp::AssertImageTypeDimensions(image, ImageType::PNG);
@@ -885,9 +877,10 @@ class PipelineWorker : public Nan::AsyncWorker {
             ->set("compression", baton->pngCompressionLevel)
             ->set("filter", baton->pngAdaptiveFiltering ? VIPS_FOREIGN_PNG_FILTER_ALL : VIPS_FOREIGN_PNG_FILTER_NONE));
           baton->formatOut = "png";
-        } else if (baton->formatOut == "webp" || isWebp || (matchInput && inputImageType == ImageType::WEBP)) {
+        } else if (baton->formatOut == "webp" || (mightMatchInput && isWebp) ||
+          (willMatchInput && inputImageType == ImageType::WEBP)) {
           // Write WEBP to file
-          AssertImageTypeDimensions(image, ImageType::WEBP);
+          sharp::AssertImageTypeDimensions(image, ImageType::WEBP);
           image.webpsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
             ->set("strip", !baton->withMetadata)
             ->set("Q", baton->webpQuality)
@@ -895,7 +888,8 @@ class PipelineWorker : public Nan::AsyncWorker {
             ->set("near_lossless", baton->webpNearLossless)
             ->set("alpha_q", baton->webpAlphaQuality));
           baton->formatOut = "webp";
-        } else if (baton->formatOut == "tiff" || isTiff || (matchInput && inputImageType == ImageType::TIFF)) {
+        } else if (baton->formatOut == "tiff" || (mightMatchInput && isTiff) ||
+          (willMatchInput && inputImageType == ImageType::TIFF)) {
           // Write TIFF to file
           if (baton->tiffCompression == VIPS_FOREIGN_TIFF_COMPRESSION_JPEG) {
             sharp::AssertImageTypeDimensions(image, ImageType::JPEG);
@@ -944,22 +938,33 @@ class PipelineWorker : public Nan::AsyncWorker {
               {"interlace", baton->jpegProgressive ? "TRUE" : "FALSE"},
               {"no_subsample", baton->jpegChromaSubsampling == "4:4:4" ? "TRUE": "FALSE"},
               {"trellis_quant", baton->jpegTrellisQuantisation ? "TRUE" : "FALSE"},
+              {"quant_table", std::to_string(baton->jpegQuantisationTable)},
               {"overshoot_deringing", baton->jpegOvershootDeringing ? "TRUE": "FALSE"},
               {"optimize_scans", baton->jpegOptimiseScans ? "TRUE": "FALSE"},
-              {"optimize_coding", "TRUE"}
+              {"optimize_coding", baton->jpegOptimiseCoding ? "TRUE": "FALSE"}
             };
             suffix = AssembleSuffixString(extname, options);
           }
           // Write DZ to file
-          image.dzsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
-            ->set("strip", !baton->withMetadata)
-            ->set("tile_size", baton->tileSize)
-            ->set("overlap", baton->tileOverlap)
-            ->set("container", baton->tileContainer)
-            ->set("layout", baton->tileLayout)
-            ->set("suffix", const_cast<char*>(suffix.data())));
+          vips::VOption *options = VImage::option()
+                                       ->set("strip", !baton->withMetadata)
+                                       ->set("tile_size", baton->tileSize)
+                                       ->set("overlap", baton->tileOverlap)
+                                       ->set("container", baton->tileContainer)
+                                       ->set("layout", baton->tileLayout)
+                                       ->set("suffix", const_cast<char*>(suffix.data()))
+                                       ->set("angle", CalculateAngleRotation(baton->tileAngle));
+
+          // libvips chooses a default depth based on layout. Instead of replicating that logic here by
+          // not passing anything - libvips will handle choice
+          if (baton->tileDepth < VIPS_FOREIGN_DZ_DEPTH_LAST) {
+            options->set("depth", baton->tileDepth);
+          }
+
+          image.dzsave(const_cast<char*>(baton->fileOut.data()), options);
           baton->formatOut = "dz";
-        } else if (baton->formatOut == "v" || isV || (matchInput && inputImageType == ImageType::VIPS)) {
+        } else if (baton->formatOut == "v" || (mightMatchInput && isV) ||
+          (willMatchInput && inputImageType == ImageType::VIPS)) {
           // Write V to file
           image.vipssave(const_cast<char*>(baton->fileOut.data()), VImage::option()
             ->set("strip", !baton->withMetadata));
@@ -1005,9 +1010,11 @@ class PipelineWorker : public Nan::AsyncWorker {
       Set(info, New("height").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(height)));
       Set(info, New("channels").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(baton->channels)));
       Set(info, New("premultiplied").ToLocalChecked(), New<v8::Boolean>(baton->premultiplied));
-      if (baton->cropCalcLeft != -1 && baton->cropCalcLeft != -1) {
-        Set(info, New("cropCalcLeft").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(baton->cropCalcLeft)));
-        Set(info, New("cropCalcTop").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(baton->cropCalcTop)));
+      if (baton->hasCropOffset) {
+        Set(info, New("cropOffsetLeft").ToLocalChecked(),
+          New<v8::Int32>(static_cast<int32_t>(baton->cropOffsetLeft)));
+        Set(info, New("cropOffsetTop").ToLocalChecked(),
+          New<v8::Int32>(static_cast<int32_t>(baton->cropOffsetTop)));
       }
 
       if (baton->bufferOutLength > 0) {
@@ -1047,18 +1054,18 @@ class PipelineWorker : public Nan::AsyncWorker {
     std::string warning = sharp::VipsWarningPop();
     while (!warning.empty()) {
       v8::Local<v8::Value> message[1] = { New(warning).ToLocalChecked() };
-      debuglog->Call(1, message);
+      debuglog->Call(1, message, async_resource);
       warning = sharp::VipsWarningPop();
     }
 
     // Decrement processing task counter
     g_atomic_int_dec_and_test(&sharp::counterProcess);
     v8::Local<v8::Value> queueLength[1] = { New<v8::Uint32>(sharp::counterQueue) };
-    queueListener->Call(1, queueLength);
+    queueListener->Call(1, queueLength, async_resource);
     delete queueListener;
 
     // Return to JavaScript
-    callback->Call(3, argv);
+    callback->Call(3, argv, async_resource);
   }
 
  private:
@@ -1188,6 +1195,9 @@ NAN_METHOD(pipeline) {
   for (unsigned int i = 0; i < 4; i++) {
     baton->background[i] = AttrTo<double>(background, i);
   }
+  // Tint chroma
+  baton->tintA = AttrTo<double>(options, "tintA");
+  baton->tintB = AttrTo<double>(options, "tintB");
   // Overlay options
   if (HasAttr(options, "overlay")) {
     baton->overlay = CreateInputDescriptor(AttrAs<v8::Object>(options, "overlay"), buffersToPersist);
@@ -1200,9 +1210,9 @@ NAN_METHOD(pipeline) {
   // Resize options
   baton->withoutEnlargement = AttrTo<bool>(options, "withoutEnlargement");
   baton->crop = AttrTo<int32_t>(options, "crop");
+  baton->embed = AttrTo<int32_t>(options, "embed");
   baton->kernel = AttrAsStr(options, "kernel");
-  baton->interpolator = AttrAsStr(options, "interpolator");
-  baton->centreSampling = AttrTo<bool>(options, "centreSampling");
+  baton->fastShrinkOnLoad = AttrTo<bool>(options, "fastShrinkOnLoad");
   // Join Channel Options
   if (HasAttr(options, "joinChannelIn")) {
     v8::Local<v8::Object> joinChannelObject = Nan::Get(options, Nan::New("joinChannelIn").ToLocalChecked())
@@ -1220,6 +1230,7 @@ NAN_METHOD(pipeline) {
   baton->flatten = AttrTo<bool>(options, "flatten");
   baton->negate = AttrTo<bool>(options, "negate");
   baton->blurSigma = AttrTo<double>(options, "blurSigma");
+  baton->medianSize = AttrTo<uint32_t>(options, "medianSize");
   baton->sharpenSigma = AttrTo<double>(options, "sharpenSigma");
   baton->sharpenFlat = AttrTo<double>(options, "sharpenFlat");
   baton->sharpenJagged = AttrTo<double>(options, "sharpenJagged");
@@ -1227,6 +1238,8 @@ NAN_METHOD(pipeline) {
   baton->thresholdGrayscale = AttrTo<bool>(options, "thresholdGrayscale");
   baton->trimTolerance = AttrTo<int32_t>(options, "trimTolerance");
   baton->gamma = AttrTo<double>(options, "gamma");
+  baton->linearA = AttrTo<double>(options, "linearA");
+  baton->linearB = AttrTo<double>(options, "linearB");
   baton->greyscale = AttrTo<bool>(options, "greyscale");
   baton->normalise = AttrTo<bool>(options, "normalise");
   baton->useExifOrientation = AttrTo<bool>(options, "useExifOrientation");
@@ -1239,6 +1252,7 @@ NAN_METHOD(pipeline) {
   baton->extendLeft = AttrTo<int32_t>(options, "extendLeft");
   baton->extendRight = AttrTo<int32_t>(options, "extendRight");
   baton->extractChannel = AttrTo<int32_t>(options, "extractChannel");
+  baton->removeAlpha = AttrTo<bool>(options, "removeAlpha");
   if (HasAttr(options, "boolean")) {
     baton->boolean = CreateInputDescriptor(AttrAs<v8::Object>(options, "boolean"), buffersToPersist);
     baton->booleanOp = sharp::GetBooleanOperation(AttrAsStr(options, "booleanOp"));
@@ -1273,8 +1287,10 @@ NAN_METHOD(pipeline) {
   baton->jpegProgressive = AttrTo<bool>(options, "jpegProgressive");
   baton->jpegChromaSubsampling = AttrAsStr(options, "jpegChromaSubsampling");
   baton->jpegTrellisQuantisation = AttrTo<bool>(options, "jpegTrellisQuantisation");
+  baton->jpegQuantisationTable = AttrTo<uint32_t>(options, "jpegQuantisationTable");
   baton->jpegOvershootDeringing = AttrTo<bool>(options, "jpegOvershootDeringing");
   baton->jpegOptimiseScans = AttrTo<bool>(options, "jpegOptimiseScans");
+  baton->jpegOptimiseCoding = AttrTo<bool>(options, "jpegOptimiseCoding");
   baton->pngProgressive = AttrTo<bool>(options, "pngProgressive");
   baton->pngCompressionLevel = AttrTo<uint32_t>(options, "pngCompressionLevel");
   baton->pngAdaptiveFiltering = AttrTo<bool>(options, "pngAdaptiveFiltering");
@@ -1298,6 +1314,7 @@ NAN_METHOD(pipeline) {
   baton->tileSize = AttrTo<uint32_t>(options, "tileSize");
   baton->tileOverlap = AttrTo<uint32_t>(options, "tileOverlap");
   std::string tileContainer = AttrAsStr(options, "tileContainer");
+  baton->tileAngle = AttrTo<int32_t>(options, "tileAngle");
   if (tileContainer == "zip") {
     baton->tileContainer = VIPS_FOREIGN_DZ_CONTAINER_ZIP;
   } else {
@@ -1312,6 +1329,17 @@ NAN_METHOD(pipeline) {
     baton->tileLayout = VIPS_FOREIGN_DZ_LAYOUT_DZ;
   }
   baton->tileFormat = AttrAsStr(options, "tileFormat");
+  std::string tileDepth = AttrAsStr(options, "tileDepth");
+  if (tileDepth == "onetile") {
+    baton->tileDepth = VIPS_FOREIGN_DZ_DEPTH_ONETILE;
+  } else if (tileDepth == "one") {
+    baton->tileDepth = VIPS_FOREIGN_DZ_DEPTH_ONE;
+  } else if (tileDepth == "onepixel") {
+    baton->tileDepth = VIPS_FOREIGN_DZ_DEPTH_ONEPIXEL;
+  } else {
+    // signal that we do not want to pass any value to dzSave
+    baton->tileDepth = VIPS_FOREIGN_DZ_DEPTH_LAST;
+  }
   // Force random access for certain operations
   if (baton->accessMethod == VIPS_ACCESS_SEQUENTIAL && (
     baton->trimTolerance != 0 || baton->normalise ||
@@ -1332,5 +1360,6 @@ NAN_METHOD(pipeline) {
   // Increment queued task counter
   g_atomic_int_inc(&sharp::counterQueue);
   v8::Local<v8::Value> queueLength[1] = { Nan::New<v8::Uint32>(sharp::counterQueue) };
-  queueListener->Call(1, queueLength);
+  v8::Local<v8::Object> recv = Nan::New<v8::Object>();
+  Nan::Call(*queueListener, recv, 1, queueLength);
 }

src/pipeline.h

@@ -62,22 +62,28 @@ struct PipelineBaton {
   int channels;
   Canvas canvas;
   int crop;
-  int cropCalcLeft;
-  int cropCalcTop;
+  int embed;
+  bool hasCropOffset;
+  int cropOffsetLeft;
+  int cropOffsetTop;
   bool premultiplied;
   std::string kernel;
-  std::string interpolator;
-  bool centreSampling;
+  bool fastShrinkOnLoad;
   double background[4];
+  double tintA;
+  double tintB;
   bool flatten;
   bool negate;
   double blurSigma;
+  int medianSize;
   double sharpenSigma;
   double sharpenFlat;
   double sharpenJagged;
   int threshold;
   bool thresholdGrayscale;
   int trimTolerance;
+  double linearA;
+  double linearB;
   double gamma;
   bool greyscale;
   bool normalise;
@@ -96,8 +102,10 @@ struct PipelineBaton {
   bool jpegProgressive;
   std::string jpegChromaSubsampling;
   bool jpegTrellisQuantisation;
+  int jpegQuantisationTable;
   bool jpegOvershootDeringing;
   bool jpegOptimiseScans;
+  bool jpegOptimiseCoding;
   bool pngProgressive;
   int pngCompressionLevel;
   bool pngAdaptiveFiltering;
@@ -123,12 +131,15 @@ struct PipelineBaton {
   VipsOperationBoolean booleanOp;
   VipsOperationBoolean bandBoolOp;
   int extractChannel;
+  bool removeAlpha;
   VipsInterpretation colourspace;
   int tileSize;
   int tileOverlap;
   VipsForeignDzContainer tileContainer;
   VipsForeignDzLayout tileLayout;
   std::string tileFormat;
+  int tileAngle;
+  VipsForeignDzDepth tileDepth;
 
   PipelineBaton():
     input(nullptr),
@@ -145,19 +156,25 @@ struct PipelineBaton {
     channels(0),
     canvas(Canvas::CROP),
     crop(0),
-    cropCalcLeft(-1),
-    cropCalcTop(-1),
+    embed(0),
+    hasCropOffset(false),
+    cropOffsetLeft(0),
+    cropOffsetTop(0),
     premultiplied(false),
-    centreSampling(false),
+    tintA(128.0),
+    tintB(128.0),
     flatten(false),
     negate(false),
     blurSigma(0.0),
+    medianSize(0),
     sharpenSigma(0.0),
     sharpenFlat(1.0),
     sharpenJagged(2.0),
     threshold(0),
     thresholdGrayscale(true),
     trimTolerance(0),
+    linearA(1.0),
+    linearB(0.0),
     gamma(0.0),
     greyscale(false),
     normalise(false),
@@ -174,15 +191,17 @@ struct PipelineBaton {
     jpegProgressive(false),
     jpegChromaSubsampling("4:2:0"),
     jpegTrellisQuantisation(false),
+    jpegQuantisationTable(0),
     jpegOvershootDeringing(false),
     jpegOptimiseScans(false),
+    jpegOptimiseCoding(true),
     pngProgressive(false),
-    pngCompressionLevel(6),
-    pngAdaptiveFiltering(true),
+    pngCompressionLevel(9),
+    pngAdaptiveFiltering(false),
     webpQuality(80),
     tiffQuality(80),
     tiffCompression(VIPS_FOREIGN_TIFF_COMPRESSION_JPEG),
-    tiffPredictor(VIPS_FOREIGN_TIFF_PREDICTOR_NONE),
+    tiffPredictor(VIPS_FOREIGN_TIFF_PREDICTOR_HORIZONTAL),
     tiffSquash(false),
     tiffXres(1.0),
     tiffYres(1.0),
@@ -196,11 +215,14 @@ struct PipelineBaton {
     booleanOp(VIPS_OPERATION_BOOLEAN_LAST),
     bandBoolOp(VIPS_OPERATION_BOOLEAN_LAST),
     extractChannel(-1),
+    removeAlpha(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),
+    tileAngle(0),
+    tileDepth(VIPS_FOREIGN_DZ_DEPTH_LAST){
       background[0] = 0.0;
       background[1] = 0.0;
       background[2] = 0.0;

src/sharp.cc

@@ -20,6 +20,7 @@
 #include "metadata.h"
 #include "pipeline.h"
 #include "utilities.h"
+#include "stats.h"
 
 NAN_MODULE_INIT(init) {
   vips_init("sharp");
@@ -46,6 +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 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 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_

test/bench/package.json

@@ -8,16 +8,16 @@
     "test": "node perf && node random && node parallel"
   },
   "devDependencies": {
-    "async": "^2.5.0",
+    "async": "^2.6.0",
     "benchmark": "^2.1.4",
-    "gm": "^1.23.0",
+    "gm": "^1.23.1",
     "imagemagick": "^0.1.3",
     "imagemagick-native": "^1.9.3",
-    "images": "^3.0.0",
+    "images": "^3.0.1",
     "jimp": "^0.2.28",
     "mapnik": "^3.6.2",
     "pajk-lwip": "^0.2.0",
-    "semver": "^5.3.0"
+    "semver": "^5.4.1"
   },
   "license": "Apache-2.0",
   "engines": {

test/bench/parallel.js

@@ -31,6 +31,7 @@ async.mapSeries([1, 1, 2, 4, 8, 16, 32, 64], function (parallelism, next) {
     function (err, ids) {
       assert(!err);
       assert(ids.length === parallelism);
+      ids.sort();
       const mean = ids.reduce(function (a, b) {
         return a + b;
       }) / ids.length;

test/bench/perf.js

@@ -601,7 +601,7 @@ async.series({
       callback(null, this.filter('fastest').map('name'));
     }).run();
   },
-  // Comparitive speed of kernels
+  // Comparative speed of kernels
   kernels: function (callback) {
     const inputJpgBuffer = fs.readFileSync(fixtures.inputJpg);
     (new Benchmark.Suite('kernels')).add('sharp-cubic', {
@@ -911,12 +911,12 @@ async.series({
             }
           });
       }
-    }).add('sharp-withoutAdaptiveFiltering', {
+    }).add('sharp-adaptiveFiltering', {
       defer: true,
       fn: function (deferred) {
         sharp(inputPngBuffer)
           .resize(width, height)
-          .png({ adaptiveFiltering: false })
+          .png({ adaptiveFiltering: true })
           .toBuffer(function (err, buffer) {
             if (err) {
               throw err;

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