Release v0.17.2

Dependency version bumps and doc refresh

.gitignore

@@ -8,9 +8,9 @@ test/saliency/report.json
 test/saliency/Image*
 test/saliency/[Uu]serData*
 !test/saliency/userData.js
-lib
-include
+vendor
 packaging/libvips*
 packaging/*.log
 !packaging/build
 .DS_Store
+.nyc_output

.jshintignore

@@ -1,4 +0,0 @@
-node_modules
-test/bench/node_modules
-test/saliency/humanae/node_modules
-coverage

.jshintrc

@@ -1,12 +0,0 @@
-{
-  "strict": true,
-  "node": true,
-  "maxparams": 4,
-  "maxcomplexity": 14,
-  "globals": {
-    "beforeEach": true,
-    "afterEach": true,
-    "describe": true,
-    "it": true
-  }
-}

.npmignore

@@ -2,15 +2,13 @@ build
 node_modules
 coverage
 .editorconfig
-.jshintignore
-.jshintrc
 .gitignore
 test
 .travis.yml
 appveyor.yml
 circle.yml
 mkdocs.yml
-lib
-include
+vendor
 packaging
 preinstall.sh
+.nyc_output

.travis.yml

@@ -1,9 +1,8 @@
 language: node_js
 node_js:
-  - "0.10"
-  - "0.12"
   - "4"
   - "6"
+  - "7"
 os:
   - linux
   - osx
@@ -18,4 +17,5 @@ osx_image: xcode8
 before_install:
   - if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then export CXX=g++-4.8; fi
 after_success:
+  - npm install coveralls
   - cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js

CONTRIBUTING.md

@@ -41,9 +41,9 @@ Any change that modifies the existing public API should be added to the relevant
 
 | Release | WIP branch |
 | ------: | :--------- |
-| v0.16.0 | pencil     |
 | v0.17.0 | quill      |
 | v0.18.0 | ridge      |
+| v0.19.0 | suit       |
 
 Please squash your changes into a single commit using a command like `git rebase -i upstream/<wip-branch>`.
 
@@ -63,6 +63,22 @@ A method to be removed should be deprecated in the next major version then remov
 
 By way of example, the [bilinearInterpolation method](https://github.com/lovell/sharp/blob/v0.6.0/index.js#L155) present in v0.5.0 was deprecated in v0.6.0 and removed in v0.7.0.
 
+## Documentation
+
+The public API is documented with [JSDoc](http://usejsdoc.org/) annotated comments.
+
+These can be converted to Markdown by running:
+```sh
+npm run docs
+```
+
+The `types.d.ts` TypeScript declaration can be generated by running:
+```sh
+npm run types
+```
+
+Please include documentation and TypeScript declaration updates in any Pull Request that modifies the public API.
+
 ## Run the tests
 
 ### Functional tests and static code analysis
@@ -90,4 +106,9 @@ npm run test-packaging
 
 ## Finally
 
-Please feel free to ask any questions via a [new issue](https://github.com/lovell/sharp/issues/new) or contact me by [e-mail](https://github.com/lovell/sharp/blob/master/package.json#L4).
+Please feel free to ask any questions via a
+[new issue](https://github.com/lovell/sharp/issues/new).
+
+If you're unable to post details publicly, please
+[e-mail](https://github.com/lovell/sharp/blob/master/package.json#L4)
+for private, paid consulting.

README.md

@@ -74,7 +74,7 @@ covers reporting bugs, requesting features and submitting code changes.
 
 ### Licence
 
-Copyright 2013, 2014, 2015, 2016 Lovell Fuller and contributors.
+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.

appveyor.yml

@@ -3,14 +3,13 @@ version: "{build}"
 build: off
 platform: x64
 environment:
-  VIPS_WARNING: 0
   matrix:
-  - nodejs_version: "0.12"
   - nodejs_version: "4"
   - nodejs_version: "6"
+  - nodejs_version: "7"
 install:
   - ps: Install-Product node $env:nodejs_version x64
   - npm install -g npm@latest
   - npm install
 test_script:
-  - npm run-script test-win
+  - npm test

binding.gyp

@@ -18,14 +18,14 @@
           'src/libvips/cplusplus/VImage.cpp'
         ],
         'include_dirs': [
-          'include',
-          'include/glib-2.0',
-          'lib/glib-2.0/include'
+          'vendor/include',
+          'vendor/include/glib-2.0',
+          'vendor/lib/glib-2.0/include'
         ],
         'libraries': [
-          '../lib/libvips.lib',
-          '../lib/libglib-2.0.lib',
-          '../lib/libgobject-2.0.lib'
+          '../vendor/lib/libvips.lib',
+          '../vendor/lib/libglib-2.0.lib',
+          '../vendor/lib/libgobject-2.0.lib'
         ],
         'configurations': {
           'Release': {
@@ -107,16 +107,16 @@
           ['OS == "linux"', {
             'defines': [
               # Inspect libvips-cpp.so to determine which C++11 ABI version was used and set _GLIBCXX_USE_CXX11_ABI accordingly. This is quite horrible.
-              '_GLIBCXX_USE_CXX11_ABI=<!(if readelf -Ws "$(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --libs-only-L vips-cpp | cut -c 3- | sed -e "s/^$/\/usr\/lib/")/libvips-cpp.so" | c++filt | grep -qF __cxx11;then echo "1";else echo "0";fi)'
+              '_GLIBCXX_USE_CXX11_ABI=<!(if readelf -Ws "$(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --variable libdir vips-cpp)/libvips-cpp.so" | c++filt | grep -qF __cxx11;then echo "1";else echo "0";fi)'
             ]
           }]
         ]
       }, {
         # Attempt to download pre-built libvips and install locally within node_modules
         'include_dirs': [
-          'include',
-          'include/glib-2.0',
-          'lib/glib-2.0/include'
+          'vendor/include',
+          'vendor/include/glib-2.0',
+          'vendor/lib/glib-2.0/include'
         ],
         'conditions': [
           ['OS == "win"', {
@@ -124,9 +124,9 @@
               '_ALLOW_KEYWORD_MACROS'
             ],
             'libraries': [
-              '../lib/libvips.lib',
-              '../lib/libglib-2.0.lib',
-              '../lib/libgobject-2.0.lib'
+              '../vendor/lib/libvips.lib',
+              '../vendor/lib/libglib-2.0.lib',
+              '../vendor/lib/libgobject-2.0.lib'
             ]
           }],
           ['OS == "mac"', {
@@ -134,12 +134,12 @@
               'download_vips': '<!(node -e "require(\'./binding\').download_vips()")'
             },
             'libraries': [
-              '../lib/libvips-cpp.42.dylib',
-              '../lib/libvips.42.dylib',
-              '../lib/libglib-2.0.0.dylib',
-              '../lib/libgobject-2.0.0.dylib',
+              '../vendor/lib/libvips-cpp.42.dylib',
+              '../vendor/lib/libvips.42.dylib',
+              '../vendor/lib/libglib-2.0.0.dylib',
+              '../vendor/lib/libgobject-2.0.0.dylib',
               # Ensure runtime linking is relative to sharp.node
-              '-rpath \'@loader_path/../../lib\''
+              '-rpath \'@loader_path/../../vendor/lib\''
             ]
           }],
           ['OS == "linux"', {
@@ -150,39 +150,39 @@
               '_GLIBCXX_USE_CXX11_ABI=0'
             ],
             'libraries': [
-              '../lib/libvips-cpp.so',
-              '../lib/libvips.so',
-              '../lib/libglib-2.0.so',
-              '../lib/libgobject-2.0.so',
+              '../vendor/lib/libvips-cpp.so',
+              '../vendor/lib/libvips.so',
+              '../vendor/lib/libglib-2.0.so',
+              '../vendor/lib/libgobject-2.0.so',
               # Dependencies of dependencies, included for openSUSE support
-              '../lib/libcairo.so',
-              '../lib/libcroco-0.6.so',
-              '../lib/libexif.so',
-              '../lib/libffi.so',
-              '../lib/libfontconfig.so',
-              '../lib/libfreetype.so',
-              '../lib/libgdk_pixbuf-2.0.so',
-              '../lib/libgif.so',
-              '../lib/libgio-2.0.so',
-              '../lib/libgmodule-2.0.so',
-              '../lib/libgsf-1.so',
-              '../lib/libgthread-2.0.so',
-              '../lib/libharfbuzz.so',
-              '../lib/libjpeg.so',
-              '../lib/liblcms2.so',
-              '../lib/liborc-0.4.so',
-              '../lib/libpango-1.0.so',
-              '../lib/libpangocairo-1.0.so',
-              '../lib/libpangoft2-1.0.so',
-              '../lib/libpixman-1.so',
-              '../lib/libpng.so',
-              '../lib/librsvg-2.so',
-              '../lib/libtiff.so',
-              '../lib/libwebp.so',
-              '../lib/libxml2.so',
-              '../lib/libz.so',
+              '../vendor/lib/libcairo.so',
+              '../vendor/lib/libcroco-0.6.so',
+              '../vendor/lib/libexif.so',
+              '../vendor/lib/libffi.so',
+              '../vendor/lib/libfontconfig.so',
+              '../vendor/lib/libfreetype.so',
+              '../vendor/lib/libgdk_pixbuf-2.0.so',
+              '../vendor/lib/libgif.so',
+              '../vendor/lib/libgio-2.0.so',
+              '../vendor/lib/libgmodule-2.0.so',
+              '../vendor/lib/libgsf-1.so',
+              '../vendor/lib/libgthread-2.0.so',
+              '../vendor/lib/libharfbuzz.so',
+              '../vendor/lib/libjpeg.so',
+              '../vendor/lib/liblcms2.so',
+              '../vendor/lib/liborc-0.4.so',
+              '../vendor/lib/libpango-1.0.so',
+              '../vendor/lib/libpangocairo-1.0.so',
+              '../vendor/lib/libpangoft2-1.0.so',
+              '../vendor/lib/libpixman-1.so',
+              '../vendor/lib/libpng.so',
+              '../vendor/lib/librsvg-2.so',
+              '../vendor/lib/libtiff.so',
+              '../vendor/lib/libwebp.so',
+              '../vendor/lib/libxml2.so',
+              '../vendor/lib/libz.so',
               # Ensure runtime linking is relative to sharp.node
-              '-Wl,--disable-new-dtags -Wl,-rpath=\'$${ORIGIN}/../../lib\''
+              '-Wl,--disable-new-dtags -Wl,-rpath=\'$${ORIGIN}/../../vendor/lib\''
             ]
           }]
         ]
@@ -230,46 +230,46 @@
         'copies': [{
           'destination': 'build/Release',
           'files': [
-            'lib/GNU.Gettext.dll',
-            'lib/libasprintf-0.dll',
-            'lib/libcairo-2.dll',
-            'lib/libcairo-gobject-2.dll',
-            'lib/libcairo-script-interpreter-2.dll',
-            'lib/libcharset-1.dll',
-            'lib/libcroco-0.6-3.dll',
-            'lib/libexif-12.dll',
-            'lib/libexpat-1.dll',
-            'lib/libffi-6.dll',
-            'lib/libfftw3-3.dll',
-            'lib/libfontconfig-1.dll',
-            'lib/libfreetype-6.dll',
-            'lib/libgcc_s_seh-1.dll',
-            'lib/libgdk_pixbuf-2.0-0.dll',
-            'lib/libgif-7.dll',
-            'lib/libgio-2.0-0.dll',
-            'lib/libglib-2.0-0.dll',
-            'lib/libgmodule-2.0-0.dll',
-            'lib/libgobject-2.0-0.dll',
-            'lib/libgsf-1-114.dll',
-            'lib/libgthread-2.0-0.dll',
-            'lib/libiconv-2.dll',
-            'lib/libintl-8.dll',
-            'lib/libjpeg-62.dll',
-            'lib/liblcms2-2.dll',
-            'lib/libpango-1.0-0.dll',
-            'lib/libpangocairo-1.0-0.dll',
-            'lib/libpangowin32-1.0-0.dll',
-            'lib/libpixman-1-0.dll',
-            'lib/libpng16-16.dll',
-            'lib/libquadmath-0.dll',
-            'lib/librsvg-2-2.dll',
-            'lib/libssp-0.dll',
-            'lib/libstdc++-6.dll',
-            'lib/libtiff-5.dll',
-            'lib/libvips-42.dll',
-            'lib/libwebp-6.dll',
-            'lib/libxml2-2.dll',
-            'lib/zlib1.dll'
+            '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-6.dll',
+            'vendor/lib/libxml2-2.dll',
+            'vendor/lib/zlib1.dll'
           ]
         }]
       }]

binding.js

@@ -1,81 +1,58 @@
 'use strict';
 
-var fs = require('fs');
-var path = require('path');
-var zlib = require('zlib');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const zlib = require('zlib');
 
-var semver = require('semver');
-var request = require('request');
-var tar = require('tar');
+const caw = require('caw');
+const got = require('got');
+const semver = require('semver');
+const tar = require('tar');
 
-var tmp = require('os').tmpdir();
-
-var distBaseUrl = 'https://dl.bintray.com/lovell/sharp/';
+const distBaseUrl = 'https://dl.bintray.com/lovell/sharp/';
 
 // Use NPM-provided environment variable where available, falling back to require-based method for Electron
-var minimumLibvipsVersion = process.env.npm_package_config_libvips || require('./package.json').config.libvips;
+const minimumLibvipsVersion = process.env.npm_package_config_libvips || require('./package.json').config.libvips;
 
-var vipsHeaderPath = path.join(__dirname, 'include', 'vips', 'vips.h');
+const platform = process.env.npm_config_platform || process.platform;
 
-var platform = process.env.npm_config_platform || process.platform;
-
-var arch = process.env.npm_config_arch || process.arch;
-var arm_version = process.env.npm_config_armv || process.config.variables.arm_version;
-
-if (arch === 'arch64' || arch === 'armhf') {
-  arch = 'arm';
-  if (arch === 'arch64') arm_version = '8';
-}
+const arch = process.env.npm_config_arch || process.arch;
 
 // -- Helpers
 
 // Does this file exist?
-var isFile = function(file) {
-  var exists = false;
+const isFile = function (file) {
   try {
-    exists = fs.statSync(file).isFile();
+    return fs.statSync(file).isFile();
   } catch (err) {}
-  return exists;
 };
 
-var unpack = function(tarPath, done) {
-  var extractor = tar.Extract({
-    path: __dirname
-  });
+const unpack = function (tarPath, done) {
+  const extractor = tar.Extract({ path: path.join(__dirname, 'vendor') });
+  if (done) {
+    extractor.on('end', done);
+  }
   extractor.on('error', error);
-  extractor.on('end', function() {
-    if (!isFile(vipsHeaderPath)) {
-      error('Could not unpack ' + tarPath);
-    }
-    if (typeof done === 'function') {
-      done();
-    }
-  });
-  fs.createReadStream(tarPath).on('error', error)
+  fs.createReadStream(tarPath)
+    .on('error', error)
     .pipe(zlib.Unzip())
     .pipe(extractor);
 };
 
-var platformId = function() {
-  var id = [platform, arch].join('-');
-  if (arch === 'arm') {
-    switch(arm_version) {
-      case '8':
-        id = id + 'v8';
-        break;
-      case '7':
-        id = id + 'v7';
-        break;
-      default:
-        id = id + 'v6';
-        break;
-    }
+const platformId = function () {
+  const platformId = [platform];
+  if (arch === 'arm' || arch === 'armhf' || arch === 'arch64') {
+    const armVersion = (arch === 'arch64') ? '8' : process.env.npm_config_armv || process.config.variables.arm_version || '6';
+    platformId.push('armv' + armVersion);
+  } else {
+    platformId.push(arch);
   }
-  return id;
+  return platformId.join('-');
 };
 
 // Error
-var error = function(msg) {
+const error = function (msg) {
   if (msg instanceof Error) {
     msg = msg.message;
   }
@@ -85,18 +62,19 @@ var error = function(msg) {
 
 // -- Binary downloaders
 
-module.exports.download_vips = function() {
+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 - please see http://sharp.dimens.io/en/stable/install/');
     }
     // Ensure glibc >= 2.15
-    var lddVersion = process.env.LDD_VERSION;
+    const lddVersion = process.env.LDD_VERSION;
     if (lddVersion) {
       if (/(glibc|gnu libc)/i.test(lddVersion)) {
-        var glibcVersion = lddVersion ? lddVersion.split(/\n/)[0].split(' ').slice(-1)[0].trim() : '';
+        const glibcVersion = lddVersion ? lddVersion.split(/\n/)[0].split(' ').slice(-1)[0].trim() : '';
         if (glibcVersion && semver.lt(glibcVersion + '.0', '2.13.0')) {
           error('glibc version ' + glibcVersion + ' requires manual installation - please see http://sharp.dimens.io/en/stable/install/');
         }
@@ -105,47 +83,47 @@ module.exports.download_vips = function() {
       }
     }
     // Arch/platform-specific .tar.gz
-    var tarFilename = ['libvips', minimumLibvipsVersion, platformId()].join('-') + '.tar.gz';
-    var tarPath = path.join(__dirname, 'packaging', tarFilename);
-    if (isFile(tarPath)) {
-      unpack(tarPath);
+    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
-      tarPath = path.join(tmp, process.pid + '-' + tarFilename);
-      var tmpFile = fs.createWriteStream(tarPath).on('finish', function() {
-        unpack(tarPath, function() {
+      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(tarPath);
+            fs.unlinkSync(tarPathTemp);
           } catch (err) {}
         });
       });
-      var options = {
-        url: distBaseUrl + tarFilename
+      const gotOpt = {
+        agent: caw(null, {
+          protocol: 'https'
+        })
       };
-      if (process.env.npm_config_https_proxy) {
-        // Use the NPM-configured HTTPS proxy
-        options.proxy = process.env.npm_config_https_proxy;
-      }
-      request(options).on('response', function(response) {
+      const url = distBaseUrl + tarFilename;
+      got.stream(url, gotOpt).on('response', function (response) {
         if (response.statusCode !== 200) {
-          error(distBaseUrl + tarFilename + ' status code ' + response.statusCode);
+          error(url + ' status code ' + response.statusCode);
         }
-      }).on('error', function(err) {
-        error('Download from ' + distBaseUrl + tarFilename + ' failed: ' + err.message);
+      }).on('error', function (err) {
+        error('Download of ' + url + ' failed: ' + err.message);
       }).pipe(tmpFile);
     }
   }
 };
 
-module.exports.use_global_vips = function() {
-  var useGlobalVips = false;
-  var globalVipsVersion = process.env.GLOBAL_VIPS_VERSION;
+module.exports.use_global_vips = function () {
+  const globalVipsVersion = process.env.GLOBAL_VIPS_VERSION;
   if (globalVipsVersion) {
-    useGlobalVips = semver.gte(
+    const useGlobalVips = semver.gte(
       globalVipsVersion,
       minimumLibvipsVersion
     );
+    process.stdout.write(useGlobalVips ? 'true' : 'false');
+  } else {
+    process.stdout.write('false');
   }
-  process.stdout.write(useGlobalVips ? 'true' : 'false');
 };

circle.yml

@@ -1,4 +1,6 @@
 machine:
+  node:
+    version: v4.6.1
   services:
     - docker
 test:

docs/api-channel.md

@@ -0,0 +1,77 @@
+<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
+
+### Table of Contents
+
+-   [extractChannel](#extractchannel)
+-   [joinChannel](#joinchannel)
+-   [bandbool](#bandbool)
+
+## extractChannel
+
+Extract a single channel from a multi-channel image.
+
+**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.
+
+**Examples**
+
+```javascript
+sharp(input)
+  .extractChannel('green')
+  .toFile('input_green.jpg', function(err, info) {
+    // info.channels === 1
+    // input_green.jpg contains the green channel of the input image
+   });
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid channel
+
+Returns **Sharp** 
+
+## joinChannel
+
+Join one or more channels to the image.
+The meaning of the added channels depends on the output colourspace, set with `toColourspace()`.
+By default the output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+Channel ordering follows vips convention:
+
+-   sRGB: 0: Red, 1: Green, 2: Blue, 3: Alpha.
+-   CMYK: 0: Magenta, 1: Cyan, 2: Yellow, 3: Black, 4: Alpha.
+
+Buffers may be any of the image formats supported by sharp: JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data.
+For raw pixel input, the `options` object should contain a `raw` attribute, which follows the format of the attribute of the same name in the `sharp()` constructor.
+
+**Parameters**
+
+-   `images` **([Array](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.
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## bandbool
+
+Perform a bitwise boolean operation on all input image channels (bands) to produce a single channel output image.
+
+**Parameters**
+
+-   `boolOp` **[String](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.
+
+**Examples**
+
+```javascript
+sharp('3-channel-rgb-input.png')
+  .bandbool(sharp.bool.and)
+  .toFile('1-channel-output.png', function (err, info) {
+    // The output will be a single channel image where each pixel `P = R & G & B`.
+    // If `I(1,1) = [247, 170, 14] = [0b11110111, 0b10101010, 0b00001111]`
+    // then `O(1,1) = 0b11110111 & 0b10101010 & 0b00001111 = 0b00000010 = 2`.
+  });
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 

docs/api-colour.md

@@ -0,0 +1,79 @@
+<!-- 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.
+The default background is `{r: 0, g: 0, b: 0, alpha: 1}`, black without transparency.
+
+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**
+
+-   `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.
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameter
+
+Returns **Sharp** 
+
+## greyscale
+
+Convert to 8-bit greyscale; 256 shades of grey.
+This is a linear operation. If the input image is in a non-linear colour space such as sRGB, use `gamma()` with `greyscale()` for the best results.
+By default the output image will be web-friendly sRGB and contain three (identical) color channels.
+This may be overridden by other sharp operations such as `toColourspace('b-w')`,
+which will produce an output image containing one color channel.
+An alpha channel may be present, and will be unchanged by the operation.
+
+**Parameters**
+
+-   `greyscale` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## grayscale
+
+Alternative spelling of `greyscale`.
+
+**Parameters**
+
+-   `grayscale` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## toColourspace
+
+Set the output colourspace.
+By default output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+
+**Parameters**
+
+-   `colourspace` **[String](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)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## toColorspace
+
+Alternative spelling of `toColourspace`.
+
+**Parameters**
+
+-   `colorspace` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)?** output colorspace.
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 

docs/api-composite.md

@@ -0,0 +1,51 @@
+<!-- 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.
+
+The overlay image must be the same size or smaller than the processed image.
+If both `top` and `left` options are provided, they take precedence over `gravity`.
+
+**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.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)?** 
+
+**Examples**
+
+```javascript
+sharp('input.png')
+  .rotate(180)
+  .resize(300)
+  .flatten()
+  .background('#ff6600')
+  .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
+  .sharpen()
+  .withMetadata()
+  .quality(90)
+  .webp()
+  .toBuffer()
+  .then(function(outputBuffer) {
+    // outputBuffer contains upside down, 300px wide, alpha channel flattened
+    // onto orange background, composited with overlay.png with SE gravity,
+    // sharpened, with metadata, 90% quality WebP image data. Phew!
+  });
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 

docs/api-constructor.md

@@ -0,0 +1,88 @@
+<!-- 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**
+
+-   `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
+     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 null or undefined.
+-   `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 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)?** 
+
+**Examples**
+
+```javascript
+sharp('input.jpg')
+  .resize(300, 200)
+  .toFile('output.jpg', function(err) {
+    // output.jpg is a 300 pixels wide and 200 pixels high image
+    // containing a scaled and cropped version of input.jpg
+  });
+```
+
+```javascript
+// Read image data from readableStream,
+// resize to 300 pixels wide,
+// emit an 'info' event with calculated dimensions
+// and finally write image data to writableStream
+var transformer = sharp()
+  .resize(300)
+  .on('info', function(info) {
+    console.log('Image height is ' + info.height);
+  });
+readableStream.pipe(transformer).pipe(writableStream);
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **[Sharp](#sharp)** 
+
+### format
+
+An Object containing nested boolean values representing the available input and output formats/methods.
+
+**Examples**
+
+```javascript
+console.log(sharp.format());
+```
+
+Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
+
+### versions
+
+An Object containing the version numbers of libvips and its dependencies.
+
+**Examples**
+
+```javascript
+console.log(sharp.versions);
+```
+
+## queue
+
+An EventEmitter that emits a `change` event when a task is either:
+
+-   queued, waiting for _libuv_ to provide a worker thread
+-   complete
+
+**Examples**
+
+```javascript
+sharp.queue.on('change', function(queueLength) {
+  console.log('Queue contains ' + queueLength + ' task(s)');
+});
+```

docs/api-input.md

@@ -0,0 +1,93 @@
+<!-- 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**
+
+```javascript
+const pipeline = sharp().rotate();
+pipeline.clone().resize(800, 600).pipe(firstWritableStream);
+pipeline.clone().extract({ left: 20, top: 20, width: 100, height: 100 }).pipe(secondWritableStream);
+readableStream.pipe(pipeline);
+// firstWritableStream receives auto-rotated, resized readableStream
+// secondWritableStream receives auto-rotated, extracted region of readableStream
+```
+
+Returns **Sharp** 
+
+## metadata
+
+Fast access to image metadata without decoding any compressed image data.
+A Promises/A+ promise is returned when `callback` is not provided.
+
+-   `format`: Name of decoder used to decompress image data e.g. `jpeg`, `png`, `webp`, `gif`, `svg`
+-   `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#L568)
+-   `channels`: Number of bands e.g. `3` for sRGB, `4` for CMYK
+-   `density`: Number of pixels per inch (DPI), if present
+-   `hasProfile`: Boolean indicating the presence of an embedded ICC profile
+-   `hasAlpha`: Boolean indicating the presence of an alpha transparency channel
+-   `orientation`: Number value of the EXIF Orientation header, if present
+-   `exif`: Buffer containing raw EXIF data, if present
+-   `icc`: Buffer containing raw [ICC](https://www.npmjs.com/package/icc) profile data, if present
+
+**Parameters**
+
+-   `callback` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)?** called with the arguments `(err, metadata)`
+
+**Examples**
+
+```javascript
+const image = sharp(inputJpg);
+image
+  .metadata()
+  .then(function(metadata) {
+    return image
+      .resize(Math.round(metadata.width / 2))
+      .webp()
+      .toBuffer();
+  })
+  .then(function(data) {
+    // data contains a WebP image half the width and height of the original JPEG
+  });
+```
+
+Returns **([Promise](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)** 
+
+## limitInputPixels
+
+Do not process input images where the number of pixels (width _ height) exceeds this limit.
+Assumes image dimensions contained in the input metadata can be trusted.
+The default limit is 268402689 (0x3FFF _ 0x3FFF) pixels.
+
+**Parameters**
+
+-   `limit` **([Number](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.
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid limit
+
+Returns **Sharp** 
+
+## sequentialRead
+
+An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`.
+This will reduce memory usage and can improve performance on some systems.
+
+**Parameters**
+
+-   `sequentialRead` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 

docs/api-operation.md

@@ -0,0 +1,320 @@
+<!-- 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
+or auto-orient based on the EXIF `Orientation` tag.
+
+Use this method without angle to determine the angle from EXIF data.
+Mirroring is supported and may infer the use of a flip operation.
+
+The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
+
+Method order is important when both rotating and extracting regions,
+for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`.
+
+**Parameters**
+
+-   `angle` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 0, 90, 180 or 270. (optional, default `auto`)
+
+**Examples**
+
+```javascript
+const pipeline = sharp()
+  .rotate()
+  .resize(null, 200)
+  .toBuffer(function (err, outputBuffer, info) {
+    // outputBuffer contains 200px high JPEG image data,
+    // auto-rotated using EXIF Orientation tag
+    // info.width and info.height contain the dimensions of the resized image
+  });
+readableStream.pipe(pipeline);
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## extract
+
+Extract a region of the image.
+
+-   Use `extract` before `resize` for pre-resize extraction.
+-   Use `extract` after `resize` for post-resize extraction.
+-   Use `extract` before and after for both.
+
+**Parameters**
+
+-   `options` **[Object](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
+
+**Examples**
+
+```javascript
+sharp(input)
+  .extract({ left: left, top: top, width: width, height: height })
+  .toFile(output, function(err) {
+    // Extract a region of the input image, saving in the same format.
+  });
+```
+
+```javascript
+sharp(input)
+  .extract({ left: leftOffsetPre, top: topOffsetPre, width: widthPre, height: heightPre })
+  .resize(width, height)
+  .extract({ left: leftOffsetPost, top: topOffsetPost, width: widthPost, height: heightPost })
+  .toFile(output, function(err) {
+    // Extract a region, resize, then extract from the resized image
+  });
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## flip
+
+Flip the image about the vertical Y axis. This always occurs after rotation, if any.
+The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
+
+**Parameters**
+
+-   `flip` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## flop
+
+Flop the image about the horizontal X axis. This always occurs after rotation, if any.
+The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
+
+**Parameters**
+
+-   `flop` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## sharpen
+
+Sharpen the image.
+When used without parameters, performs a fast, mild sharpen of the output image.
+When a `sigma` is provided, performs a slower, more accurate sharpen of the L channel in the LAB colour space.
+Separate control over the level of sharpening in "flat" and "jagged" areas is available.
+
+**Parameters**
+
+-   `sigma` **[Number](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`)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## blur
+
+Blur the image.
+When used without parameters, performs a fast, mild blur of the output image.
+When a `sigma` is provided, performs a slower, more accurate Gaussian blur.
+
+**Parameters**
+
+-   `sigma` **[Number](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`.
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## extend
+
+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**
+
+-   `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)?** 
+
+**Examples**
+
+```javascript
+// Resize to 140 pixels wide, then add 10 transparent pixels
+// to the top, left and right edges and 20 to the bottom edge
+sharp(input)
+  .resize(140)
+  .background({r: 0, g: 0, b: 0, alpha: 0})
+  .extend({top: 10, bottom: 20, left: 10, right: 10})
+  ...
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## flatten
+
+Merge alpha transparency channel, if any, with `background`.
+
+**Parameters**
+
+-   `flatten` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## trim
+
+Trim "boring" pixels from all edges that contain values within a percentage similarity of the top-left pixel.
+
+**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`)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## gamma
+
+Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma`
+then increasing the encoding (brighten) post-resize at a factor of `gamma`.
+This can improve the perceived brightness of a resized image in non-linear colour spaces.
+JPEG and WebP input images will not take advantage of the shrink-on-load performance optimisation
+when applying a gamma correction.
+
+**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`)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## negate
+
+Produce the "negative" of the image.
+
+**Parameters**
+
+-   `negate` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## normalise
+
+Enhance output image contrast by stretching its luminance to cover the full dynamic range.
+
+**Parameters**
+
+-   `normalise` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## normalize
+
+Alternative spelling of normalise.
+
+**Parameters**
+
+-   `normalize` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 
+
+## convolve
+
+Convolve the image with the specified kernel.
+
+**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`)
+
+**Examples**
+
+```javascript
+sharp(input)
+  .convolve({
+    width: 3,
+    height: 3,
+    kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1]
+  })
+  .raw()
+  .toBuffer(function(err, data, info) {
+    // data contains the raw pixel data representing the convolution
+    // of the input image with the horizontal Sobel operator
+  });
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## threshold
+
+Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
+
+**Parameters**
+
+-   `threshold` **[Number](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`)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## boolean
+
+Perform a bitwise boolean operation with operand image.
+
+This operation creates an output image where each pixel is the result of
+the selected bitwise boolean `operation` between the corresponding pixels of the input images.
+
+**Parameters**
+
+-   `operand` **([Buffer](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)?** 
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 

docs/api-output.md

@@ -0,0 +1,193 @@
+<!-- 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.
+
+If an explicit output format is not selected, it will be inferred from the extension,
+with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
+Note that raw pixel data is only supported for buffer output.
+
+A Promises/A+ promise is returned when `callback` is not provided.
+
+**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)`.
+    `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+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
+
+## toBuffer
+
+Write output to a Buffer.
+JPEG, PNG, WebP, and RAW output are supported.
+By default, the format will match the input image, except GIF and SVG input which become PNG output.
+
+`callback`, if present, gets three arguments `(err, buffer, info)` where:
+
+-   `err` is an error message, if any.
+-   `buffer` is the output image data.
+-   `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
+    A Promises/A+ promise is returned when `callback` is not provided.
+
+**Parameters**
+
+-   `callback` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)?** 
+
+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
+
+## withMetadata
+
+Include all metadata (EXIF, XMP, IPTC) from the input image in the output image.
+The default behaviour, when `withMetadata` is not used, is to strip all metadata and convert to the device-independent sRGB colour space.
+This will also convert to and add a web-friendly sRGB ICC profile.
+
+**Parameters**
+
+-   `withMetadata` **[Object](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.
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## jpeg
+
+Use these JPEG options for output image.
+
+**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`)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid options
+
+Returns **Sharp** 
+
+## png
+
+Use these PNG options for output image.
+
+**Parameters**
+
+-   `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`)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid options
+
+Returns **Sharp** 
+
+## webp
+
+Use these WebP options for output image.
+
+**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`)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid options
+
+Returns **Sharp** 
+
+## tiff
+
+Use these TIFF options for output image.
+
+**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`)
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid options
+
+Returns **Sharp** 
+
+## raw
+
+Force output to be raw, uncompressed uint8 pixel data.
+
+Returns **Sharp** 
+
+## toFormat
+
+Force output to a given format.
+
+**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
+
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** unsupported format or options
+
+Returns **Sharp** 
+
+## tile
+
+Use tile-based deep zoom (image pyramid) output.
+Set the format and options for tile images via the `toFormat`, `jpeg`, `png` or `webp` functions.
+Use a `.zip` or `.szi` file extension with `toFile` to write to a compressed archive file format.
+
+**Parameters**
+
+-   `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'`)
+
+**Examples**
+
+```javascript
+sharp('input.tiff')
+  .png()
+  .tile({
+    size: 512
+  })
+  .toFile('output.dz', function(err, info) {
+    // output.dzi is the Deep Zoom XML definition
+    // output_files contains 512x512 tiles grouped by zoom level
+  });
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 

docs/api-resize.md

@@ -0,0 +1,176 @@
+<!-- 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:
+
+-   `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.
+
+**Parameters**
+
+-   `width` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** pixels wide the resultant image should be, between 1 and 16383 (0x3FFF). Use `null` or `undefined` to auto-scale the width to match the height.
+-   `height` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** pixels high the resultant image should be, between 1 and 16383. 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**
+
+```javascript
+sharp(inputBuffer)
+  .resize(200, 300, {
+    kernel: sharp.kernel.lanczos2,
+    interpolator: sharp.interpolator.nohalo
+  })
+  .background('white')
+  .embed()
+  .toFile('output.tiff')
+  .then(function() {
+    // output.tiff is a 200 pixels wide and 300 pixels high image
+    // containing a lanczos2/nohalo 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
+
+Returns **Sharp** 
+
+## crop
+
+Crop the resized image to the exact size specified, the default behaviour.
+
+Possible attributes of the optional `sharp.gravity` are `north`, `northeast`, `east`, `southeast`, `south`,
+`southwest`, `west`, `northwest`, `center` and `centre`.
+
+The experimental strategy-based approach resizes so one dimension is at its target length
+then repeatedly ranks edge regions, discarding the edge with the lowest score based on the selected strategy.
+
+-   `entropy`: focus on the region with the highest [Shannon entropy](https://en.wikipedia.org/wiki/Entropy_%28information_theory%29).
+-   `attention`: focus on the region with the highest luminance frequency, colour saturation and presence of skin tones.
+
+**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'`)
+
+**Examples**
+
+```javascript
+const transformer = sharp()
+  .resize(200, 200)
+  .crop(sharp.strategy.entropy)
+  .on('error', function(err) {
+    console.log(err);
+  });
+// Read image data from readableStream
+// Write 200px square auto-cropped image data to writableStream
+readableStream.pipe(transformer).pipe(writableStream);
+```
+
+-   Throws **[Error](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error)** Invalid parameters
+
+Returns **Sharp** 
+
+## embed
+
+Preserving aspect ratio, resize the image to the maximum `width` or `height` specified
+then embed on a background of the exact `width` and `height` specified.
+
+If the background contains an alpha value then WebP and PNG format output images will
+contain an alpha channel, even when the input image does not.
+
+**Examples**
+
+```javascript
+sharp('input.gif')
+  .resize(200, 300)
+  .background({r: 0, g: 0, b: 0, alpha: 0})
+  .embed()
+  .toFormat(sharp.format.webp)
+  .toBuffer(function(err, outputBuffer) {
+    if (err) {
+      throw err;
+    }
+    // outputBuffer contains WebP image data of a 200 pixels wide and 300 pixels high
+    // containing a scaled version, embedded on a transparent canvas, of input.gif
+  });
+```
+
+Returns **Sharp** 
+
+## max
+
+Preserving aspect ratio, resize the image to be as large as possible
+while ensuring its dimensions are less than or equal to the `width` and `height` specified.
+
+Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
+
+**Examples**
+
+```javascript
+sharp(inputBuffer)
+  .resize(200, 200)
+  .max()
+  .toFormat('jpeg')
+  .toBuffer()
+  .then(function(outputBuffer) {
+    // outputBuffer contains JPEG image data no wider than 200 pixels and no higher
+    // than 200 pixels regardless of the inputBuffer image dimensions
+  });
+```
+
+Returns **Sharp** 
+
+## min
+
+Preserving aspect ratio, resize the image to be as small as possible
+while ensuring its dimensions are greater than or equal to the `width` and `height` specified.
+
+Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
+
+Returns **Sharp** 
+
+## ignoreAspectRatio
+
+Ignoring the aspect ratio of the input, stretch the image to
+the exact `width` and/or `height` provided via `resize`.
+
+Returns **Sharp** 
+
+## withoutEnlargement
+
+Do not enlarge the output image if the input image width _or_ height are already less than the required dimensions.
+This is equivalent to GraphicsMagick's `>` geometry option:
+"_change the dimensions of the image only if its width or height exceeds the geometry specification_".
+
+**Parameters**
+
+-   `withoutEnlargement` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `true`)
+
+Returns **Sharp** 

docs/api-utility.md

@@ -0,0 +1,106 @@
+<!-- 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.
+Existing entries in the cache will be trimmed after any change in limits.
+This method always returns cache statistics,
+useful for determining how much working memory is required for a particular task.
+
+**Parameters**
+
+-   `options` **([Object](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.
+    -   `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`)
+
+**Examples**
+
+```javascript
+const stats = sharp.cache();
+```
+
+```javascript
+sharp.cache( { items: 200 } );
+sharp.cache( { files: 0 } );
+sharp.cache(false);
+```
+
+Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
+
+## concurrency
+
+Gets, or when a concurrency is provided sets,
+the number of threads _libvips'_ should create to process each image.
+The default value is the number of CPU cores.
+A value of `0` will reset to this default.
+
+The maximum number of images that can be processed in parallel
+is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
+
+This method always returns the current concurrency.
+
+**Parameters**
+
+-   `concurrency` **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)?** 
+
+**Examples**
+
+```javascript
+const threads = sharp.concurrency(); // 4
+sharp.concurrency(2); // 2
+sharp.concurrency(0); // 4
+```
+
+Returns **[Number](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)** concurrency
+
+## counters
+
+Provides access to internal task counters.
+
+-   queue is the number of tasks this module has queued waiting for _libuv_ to provide a worker thread from its pool.
+-   process is the number of resize tasks currently being processed.
+
+**Examples**
+
+```javascript
+const counters = sharp.counters(); // { queue: 2, process: 4 }
+```
+
+Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
+
+## simd
+
+Get and set use of SIMD vector unit instructions.
+Requires libvips to have been compiled with liborc support.
+
+Improves the performance of `resize`, `blur` and `sharpen` operations
+by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM NEON.
+
+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**
+
+-   `simd` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?**  (optional, default `false`)
+
+**Examples**
+
+```javascript
+const simd = sharp.simd();
+// simd is `true` if SIMD is currently enabled
+```
+
+```javascript
+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)** 

docs/api.md

@@ -1,838 +0,0 @@
-# API
-
-```javascript
-var sharp = require('sharp');
-```
-
-### Input
-
-#### sharp([input], [options])
-
-Constructor to which further methods are chained.
-
-`input`, if present, can be one of:
-
-* Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
-* String containing the path to an 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 `input` is `null` or `undefined`.
-
-`options`, if present, is an Object with the following optional attributes:
-
-* `density` an integral number representing the DPI for vector images, defaulting to 72.
-* `raw` an Object containing `width`, `height` and `channels` when providing uncompressed data. See `raw()` for pixel ordering.
-
-The object returned by the constructor implements the
-[stream.Duplex](http://nodejs.org/api/stream.html#stream_class_stream_duplex) class.
-
-JPEG, PNG or WebP format image data can be streamed out from this object.
-When using Stream based output, derived attributes are available from the `info` event.
-
-```javascript
-sharp('input.jpg')
-  .resize(300, 200)
-  .toFile('output.jpg', function(err) {
-    // output.jpg is a 300 pixels wide and 200 pixels high image
-    // containing a scaled and cropped version of input.jpg
-  });
-```
-
-```javascript
-// Read image data from readableStream,
-// resize to 300 pixels wide,
-// emit an 'info' event with calculated dimensions
-// and finally write image data to writableStream
-var transformer = sharp()
-  .resize(300)
-  .on('info', function(info) {
-    console.log('Image height is ' + info.height);
-  });
-readableStream.pipe(transformer).pipe(writableStream);
-```
-
-#### metadata([callback])
-
-Fast access to image metadata without decoding any compressed image data.
-
-`callback`, if present, gets the arguments `(err, metadata)` where `metadata` has the attributes:
-
-* `format`: Name of decoder 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`, `scrgb`, `cmyk`, `lab`, `xyz`, `b-w` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568)
-* `channels`: Number of bands e.g. `3` for sRGB, `4` for CMYK
-* `density`: Number of pixels per inch (DPI), if present
-* `hasProfile`: Boolean indicating the presence of an embedded ICC profile
-* `hasAlpha`: Boolean indicating the presence of an alpha transparency channel
-* `orientation`: Number value of the EXIF Orientation header, if present
-* `exif`: Buffer containing raw EXIF data, if present
-* `icc`: Buffer containing raw [ICC](https://www.npmjs.com/package/icc) profile data, if present
-
-A Promises/A+ promise is returned when `callback` is not provided.
-
-```javascript
-var image = sharp(inputJpg);
-image
-  .metadata()
-  .then(function(metadata) {
-    return image
-      .resize(Math.round(metadata.width / 2))
-      .webp()
-      .toBuffer();
-  })
-  .then(function(data) {
-    // data contains a WebP image half the width and height of the original JPEG
-  });
-```
-
-#### clone()
-
-Takes a "snapshot" of the instance, returning a new instance.
-Cloned instances inherit the input of their parent instance.
-
-This allows multiple output Streams
-and therefore multiple processing pipelines
-to share a single input Stream.
-
-```javascript
-var pipeline = sharp().rotate();
-pipeline.clone().resize(800, 600).pipe(firstWritableStream);
-pipeline.clone().extract({ left: 20, top: 20, width: 100, height: 100 }).pipe(secondWritableStream);
-readableStream.pipe(pipeline);
-// firstWritableStream receives auto-rotated, resized readableStream
-// secondWritableStream receives auto-rotated, extracted region of readableStream
-```
-
-#### sequentialRead()
-
-An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`.
-This will reduce memory usage and can improve performance on some systems.
-
-#### limitInputPixels(pixels)
-
-Do not process input images where the number of pixels (width * height) exceeds this limit.
-
-`pixels` is either an integral Number of pixels, with a value between 1 and the default 268402689 (0x3FFF * 0x3FFF) or
- a boolean. `false` will disable checking while `true` will revert to the default limit.
-
-### Resizing
-
-#### resize([width], [height], [options])
-
-Scale output to `width` x `height`. By default, the resized image is cropped to the exact size specified.
-
-`width` is the integral Number of pixels wide the resultant image should be, between 1 and 16383 (0x3FFF). Use `null` or `undefined` to auto-scale the width to match the height.
-
-`height` is the integral Number of pixels high the resultant image should be, between 1 and 16383. Use `null` or `undefined` to auto-scale the height to match the width.
-
-`options` is an optional Object. If present, it can contain one or more of:
-
-* `options.kernel`, the kernel to use for image reduction, defaulting to `lanczos3`.
-* `options.interpolator`, the interpolator to use for image enlargement, defaulting to `bicubic`.
-
-Possible kernels are:
-
-* `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 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.
-
-```javascript
-sharp(inputBuffer)
-  .resize(200, 300, {
-    kernel: sharp.kernel.lanczos2,
-    interpolator: sharp.interpolator.nohalo
-  })
-  .background('white')
-  .embed()
-  .toFile('output.tiff')
-  .then(function() {
-    // output.tiff is a 200 pixels wide and 300 pixels high image
-    // containing a lanczos2/nohalo scaled version, embedded on a white canvas,
-    // of the image data in inputBuffer
-  });
-```
-
-#### crop([option])
-
-Crop the resized image to the exact size specified, the default behaviour.
-
-`option`, if present, is an attribute of:
-
-* `sharp.gravity` e.g. `sharp.gravity.north`, to crop to an edge or corner, or
-* `sharp.strategy` e.g. `sharp.strategy.entropy`, to crop dynamically.
-
-Possible attributes of `sharp.gravity` are
-`north`, `northeast`, `east`, `southeast`, `south`,
-`southwest`, `west`, `northwest`, `center` and `centre`.
-
-The experimental strategy-based approach resizes so one dimension is at its target length
-then repeatedly ranks edge regions, discarding the edge with the lowest score based on the selected strategy.
-
-* `entropy`: focus on the region with the highest [Shannon entropy](https://en.wikipedia.org/wiki/Entropy_%28information_theory%29).
-* `attention`: focus on the region with the highest luminance frequency, colour saturation and presence of skin tones.
-
-The default crop option is a `center`/`centre` gravity.
-
-```javascript
-var transformer = sharp()
-  .resize(200, 200)
-  .crop(sharp.strategy.entropy)
-  .on('error', function(err) {
-    console.log(err);
-  });
-// Read image data from readableStream
-// Write 200px square auto-cropped image data to writableStream
-readableStream.pipe(transformer).pipe(writableStream);
-```
-
-#### embed()
-
-Preserving aspect ratio, resize the image to the
-maximum `width` or `height` specified
-then embed on a background of the exact
-`width` and `height` specified.
-
-If the background contains an alpha value
-then WebP and PNG format output images will
-contain an alpha channel,
-even when the input image does not.
-
-```javascript
-sharp('input.gif')
-  .resize(200, 300)
-  .background({r: 0, g: 0, b: 0, a: 0})
-  .embed()
-  .toFormat(sharp.format.webp)
-  .toBuffer(function(err, outputBuffer) {
-    if (err) {
-      throw err;
-    }
-    // outputBuffer contains WebP image data of a 200 pixels wide and 300 pixels high
-    // containing a scaled version, embedded on a transparent canvas, of input.gif
-  });
-```
-
-#### max()
-
-Preserving aspect ratio,
-resize the image to be as large as possible
-while ensuring its dimensions are less than or equal to
-the `width` and `height` specified.
-
-Both `width` and `height` must be provided via
-`resize` otherwise the behaviour will default to `crop`.
-
-```javascript
-sharp(inputBuffer)
-  .resize(200, 200)
-  .max()
-  .toFormat('jpeg')
-  .toBuffer()
-  .then(function(outputBuffer) {
-    // outputBuffer contains JPEG image data no wider than 200 pixels and no higher
-    // than 200 pixels regardless of the inputBuffer image dimensions
-  });
-```
-
-#### min()
-
-Preserving aspect ratio,
-resize the image to be as small as possible
-while ensuring its dimensions are greater than or equal to
-the `width` and `height` specified.
-
-Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
-
-#### withoutEnlargement()
-
-Do not enlarge the output image
-if the input image width *or* height
-are already less than the required dimensions.
-
-This is equivalent to GraphicsMagick's `>` geometry option:
-"*change the dimensions of the image only
-if its width or height exceeds the geometry specification*".
-
-#### ignoreAspectRatio()
-
-Ignoring the aspect ratio of the input, stretch the image to the exact `width` and/or `height` provided via `resize`.
-
-### Operations
-
-#### extract({ left: left, top: top, width: width, height: height })
-
-Extract a region of the image. Can be used with or without a `resize` operation.
-
-`left` and `top` are the offset, in pixels, from the top-left corner.
-
-`width` and `height` are the dimensions of the extracted image.
-
-Use `extract` before `resize` for pre-resize extraction. Use `extract` after `resize` for post-resize extraction. Use `extract` before and after for both.
-
-```javascript
-sharp(input)
-  .extract({ left: left, top: top, width: width, height: height })
-  .toFile(output, function(err) {
-    // Extract a region of the input image, saving in the same format.
-  });
-```
-
-```javascript
-sharp(input)
-  .extract({ left: leftOffsetPre, top: topOffsetPre, width: widthPre, height: heightPre })
-  .resize(width, height)
-  .extract({ left: leftOffsetPost, top: topOffsetPost, width: widthPost, height: heightPost })
-  .toFile(output, function(err) {
-    // Extract a region, resize, then extract from the resized image
-  });
-```
-
-#### trim([tolerance])
-
-Trim "boring" pixels from all edges that contain values within a percentage similarity of the top-left pixel.
-
-* `tolerance`, if present, is an integral Number between 1 and 99 representing the percentage similarity, defaulting to 10.
-
-#### background(rgba)
-
-Set the background for the `embed`, `flatten` and `extend` operations.
-
-`rgba` is parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
-
-The alpha value is a float between `0` (transparent) and `1` (opaque).
-
-The default background is `{r: 0, g: 0, b: 0, a: 1}`, black without transparency.
-
-#### flatten()
-
-Merge alpha transparency channel, if any, with `background`.
-
-#### extend(extension)
-
-Extends/pads the edges of the image with `background`, where `extension` is one of:
-
-* a Number representing the pixel count to add to each edge, or
-* an Object containing `top`, `left`, `bottom` and `right` attributes, each a Number of pixels to add to that edge.
-
-This operation will always occur after resizing and extraction, if any.
-
-```javascript
-// Resize to 140 pixels wide, then add 10 transparent pixels
-// to the top, left and right edges and 20 to the bottom edge
-sharp(input)
-  .resize(140)
-  .background({r: 0, g: 0, b: 0, a: 0})
-  .extend({top: 10, bottom: 20, left: 10, right: 10})
-  ...
-```
-
-#### negate()
-
-Produces the "negative" of the image.  White => Black, Black => White, Blue => Yellow, etc.
-
-#### rotate([angle])
-
-Rotate the output image by either an explicit angle or auto-orient based on the EXIF `Orientation` tag.
-
-`angle`, if present, is a Number with a value of `0`, `90`, `180` or `270`.
-
-Use this method without `angle` to determine the angle from EXIF data. Mirroring is supported and may infer the use of a `flip` operation.
-
-Method order is important when both rotating and extracting regions, for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`.
-
-The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
-
-```javascript
-var pipeline = sharp()
-  .rotate()
-  .resize(null, 200)
-  .progressive()
-  .toBuffer(function(err, outputBuffer, info) {
-    if (err) {
-      throw err;
-    }
-    // outputBuffer contains 200px high progressive JPEG image data,
-    // auto-rotated using EXIF Orientation tag
-    // info.width and info.height contain the dimensions of the resized image
-  });
-readableStream.pipe(pipeline);
-```
-
-#### flip()
-
-Flip the image about the vertical Y axis. This always occurs after rotation, if any.
-The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
-
-#### flop()
-
-Flop the image about the horizontal X axis. This always occurs after rotation, if any.
-The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
-
-#### blur([sigma])
-
-When used without parameters, performs a fast, mild blur of the output image. This typically reduces performance by 10%.
-
-When a `sigma` is provided, performs a slower, more accurate Gaussian blur. This typically reduces performance by 25%.
-
-* `sigma`, if present, is a Number between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
-
-#### convolve(kernel)
-
-Convolve the image with the specified `kernel`, an Object with the following attributes:
-
-* `width` is an integral Number representing the width of the kernel in pixels.
-* `height` is an integral Number representing the width of the kernel in pixels.
-* `kernel` is an Array of length `width*height` containing the kernel values.
-* `scale`, if present, is a Number representing the scale of the kernel in pixels, defaulting to the sum of the kernel's values.
-* `offset`, if present, is a Number representing the offset of the kernel in pixels, defaulting to 0.
-
-```javascript
-sharp(input)
-  .convolve({
-    width: 3,
-    height: 3,
-    kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1]
-  })
-  .raw()
-  .toBuffer(function(err, data, info) {
-    // data contains the raw pixel data representing the convolution
-    // of the input image with the horizontal Sobel operator
-  });
-```
-
-#### sharpen([sigma], [flat], [jagged])
-
-When used without parameters, performs a fast, mild sharpen of the output image. This typically reduces performance by 10%.
-
-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. This typically reduces performance by 50%.
-
-* `sigma`, if present, is a Number representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
-* `flat`, if present, is a Number representing the level of sharpening to apply to "flat" areas, defaulting to a value of 1.0.
-* `jagged`, if present, is a Number representing the level of sharpening to apply to "jagged" areas, defaulting to a value of 2.0.
-
-#### threshold([threshold], [options])
-
-Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
-By default, the image will be converted to single channel greyscale before thresholding.
-
-* `threshold`, if present, is a Number between 0 and 255, representing the level at which the threshold will be applied. The default threshold is 128.
-* `options`, if present, is an Object containing a Boolean `greyscale` (or `grayscale`). When `false` each channel will have the threshold applied independently.
-
-#### gamma([gamma])
-
-Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma` then increasing the encoding (brighten) post-resize at a factor of `gamma`.
-
-`gamma`, if present, is a Number between 1 and 3. The default value is `2.2`, a suitable approximation for sRGB images.
-
-This can improve the perceived brightness of a resized image in non-linear colour spaces.
-
-JPEG input images will not take advantage of the shrink-on-load performance optimisation when applying a gamma correction.
-
-#### grayscale() / greyscale()
-
-Convert to 8-bit greyscale; 256 shades of grey.
-
-This is a linear operation. If the input image is in a non-linear colour space such as sRGB, use `gamma()` with `greyscale()` for the best results.
-
-By default the output image will be web-friendly sRGB and contain three (identical) color channels. This may be overridden by other sharp operations such as `toColourspace('b-w')`, which will produce an output image containing one color channel. An alpha channel may be present, and will be unchanged by the operation.
-
-#### normalize() / normalise()
-
-Enhance output image contrast by stretching its luminance to cover the full dynamic range. This typically reduces performance by 30%.
-
-#### overlayWith(image, [options])
-
-Overlay (composite) a image over the processed (resized, extracted etc.) image.
-
-`image` is one of the following, and must be the same size or smaller than the processed image:
-
-* Buffer containing image data, or
-* String containing the path to an image file
-
-`options`, if present, is an Object with the following optional attributes:
-
-* `gravity` is a String or an attribute of the `sharp.gravity` Object e.g. `sharp.gravity.north` at which to place the overlay, defaulting to `center`/`centre`.
-* `top` is an integral Number representing the pixel offset from the top edge.
-* `left` is an integral Number representing the pixel offset from the left edge.
-* `tile` is a Boolean, defaulting to `false`. When set to `true` repeats the overlay image across the entire image with the given `gravity`.
-* `cutout` is a Boolean, defaulting to `false`. When set to `true` applies only the alpha channel of the overlay image to the image to be overlaid, giving the appearance of one image being cut out of another.
-* `raw` an Object containing `width`, `height` and `channels` when providing uncompressed data.
-
-If both `top` and `left` are provided, they take precedence over `gravity`.
-
-```javascript
-sharp('input.png')
-  .rotate(180)
-  .resize(300)
-  .flatten()
-  .background('#ff6600')
-  .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
-  .sharpen()
-  .withMetadata()
-  .quality(90)
-  .webp()
-  .toBuffer()
-  .then(function(outputBuffer) {
-    // outputBuffer contains upside down, 300px wide, alpha channel flattened
-    // onto orange background, composited with overlay.png with SE gravity,
-    // sharpened, with metadata, 90% quality WebP image data. Phew!
-  });
-```
-
-#### toColourspace(colourspace) / toColorspace(colorspace)
-
-Set the output colourspace. By default output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.  
-  
-`colourspace` is a string or `sharp.colourspace` enum that identifies an output colourspace. String arguments comprise vips colour space interpretation names  e.g. `srgb`, `rgb`, `scrgb`, `cmyk`, `lab`, `xyz`, `b-w` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568)
-  
-#### extractChannel(channel)
-
-Extract a single channel from a multi-channel image.
-
-`channel` is a zero-indexed integral Number representing the band number to extract. `red`, `green` or `blue` are also accepted as an alternative to `0`, `1` or `2` respectively.
-
-```javascript
-sharp(input)
-  .extractChannel('green')
-  .toFile('input_green.jpg', function(err, info) {
-    // info.channels === 1
-    // input_green.jpg contains the green channel of the input image
-   });
-```
-
-#### joinChannel(channels, [options])
-
-Join a data channel to the image. The meaning of the added channels depends on the output colourspace, set with `toColourspace()`. By default the output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
-
-`channels` is one of
-* a single file path
-* an array of file paths
-* a single buffer
-* an array of buffers
-
-Note that channel ordering follows vips convention:
-* sRGB: 0: Red, 1: Green, 2: Blue, 3: Alpha
-* CMYK: 0: Magenta, 1: Cyan, 2: Yellow, 3: Black, 4: Alpha
-
-Buffers may be any of the image formats supported by sharp: JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data. In the case of a RAW buffer, the `options` object should contain a `raw` attribute, which follows the format of the attribute of the same name in the `sharp()` constructor. See `sharp()` for details. See `raw()` for pixel ordering. 
-
-#### bandbool(operation)
-
-Perform a bitwise boolean operation on all input image channels (bands) to produce a single channel output image.
-
-`operation` is a string containing the name of the bitwise operator to be appled to image channels, which can be one of:
-
-* `and` performs a bitwise and operation, like the c-operator `&`.
-* `or` performs a bitwise or operation, like the c-operator `|`.
-* `eor` performs a bitwise exclusive or operation, like the c-operator `^`.
-
-```javascript
-sharp('input.png')
-  .bandbool(sharp.bool.and)
-  .toFile('output.png')
-```
-
-In the above example if `input.png` is a 3 channel RGB image, `output.png` will be a 1 channel grayscale image where each pixel `P = R & G & B`.
-For example, if `I(1,1) = [247, 170, 14] = [0b11110111, 0b10101010, 0b00001111]` then `O(1,1) = 0b11110111 & 0b10101010 & 0b00001111 = 0b00000010 = 2`.
-
-#### boolean(image, operation, [options])
-
-Perform a bitwise boolean operation with `image`, where `image` is one of the following:
-
-* Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
-* String containing the path to an image file
-
-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.
-The boolean operation can be one of the following:
-
-* `and` performs a bitwise and operation, like the c-operator `&`.
-* `or` performs a bitwise or operation, like the c-operator `|`.
-* `eor` performs a bitwise exclusive or operation, like the c-operator `^`.
-
-`options`, if present, is an Object with the following optional attributes:
-
-* `raw` an Object containing `width`, `height` and `channels` when providing uncompressed data.
-
-### Output
-
-#### toFile(path, [callback])
-
-`path` is a String containing the path to write the image data to.
-
-If an explicit output format is not selected, it will be inferred from the extension, with JPEG, PNG, WebP, TIFF, DZI, and VIPS V format supported. Note that RAW format is only supported for buffer output.
-
-`callback`, if present, is called with two arguments `(err, info)` where:
-
-* `err` contains an error message, if any.
-* `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
-
-A Promises/A+ promise is returned when `callback` is not provided.
-
-#### toBuffer([callback])
-
-Write image data to a Buffer, the format of which will match the input image by default. JPEG, PNG, WebP, and RAW are supported.
-
-`callback`, if present, gets three arguments `(err, buffer, info)` where:
-
-* `err` is an error message, if any.
-* `buffer` is the output image data.
-* `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
-
-A Promises/A+ promise is returned when `callback` is not provided.
-
-#### jpeg()
-
-Use JPEG format for the output image.
-
-#### png()
-
-Use PNG format for the output image.
-
-#### webp()
-
-Use WebP format for the output image.
-
-#### raw()
-
-Provide raw, uncompressed uint8 (unsigned char) image data for Buffer and Stream based output.
-
-The number of channels depends on the input image and selected options.
-
-* 1 channel for images converted to `greyscale()`, with each byte representing one pixel.
-* 3 channels for colour images without alpha transparency, with bytes ordered \[red, green, blue, red, green, blue, etc.\]).
-* 4 channels for colour images with alpha transparency, with bytes ordered \[red, green, blue, alpha, red, green, blue, alpha, etc.\].
-
-#### toFormat(format)
-
-Convenience method for the above output format methods, where `format` is either:
-
-* an attribute of the `sharp.format` Object e.g. `sharp.format.jpeg`, or
-* a String containing `jpeg`, `png`, `webp` or `raw`.
-
-#### quality(quality)
-
-The output quality to use for lossy JPEG, WebP and TIFF output formats. The default quality is `80`.
-
-`quality` is a Number between 1 and 100.
-
-#### progressive()
-
-Use progressive (interlace) scan for JPEG and PNG output. This typically reduces compression performance by 30% but results in an image that can be rendered sooner when decompressed.
-
-#### withMetadata([metadata])
-
-Include all metadata (EXIF, XMP, IPTC) from the input image in the output image.
-This will also convert to and add the latest web-friendly v2 sRGB ICC profile.
-
-The optional `metadata` parameter, if present, is an Object with the attributes to update.
-New attributes cannot be inserted, only existing attributes updated.
-
-* `orientation` is an integral Number between 1 and 8, used to update the value of the EXIF `Orientation` tag.
-This has no effect if the input image does not have an EXIF `Orientation` tag.
-
-The default behaviour, when `withMetadata` is not used, is to strip all metadata and convert to the device-independent sRGB colour space.
-
-#### tile(options)
-
-The size, overlap, container and directory layout to use when generating square Deep Zoom image pyramid tiles.
-
-`options` is an Object with one or more of the following attributes:
-
-* `size` is an integral Number between 1 and 8192. The default value is 256 pixels.
-* `overlap` is an integral Number between 0 and 8192. The default value is 0 pixels.
-* `container` is a String, with value `fs` or `zip`. The default value is `fs`.
-* `layout` is a String, with value `dz`, `zoomify` or `google`. The default value is `dz`.
-
-You can also use the file extension `.zip` or `.szi` to write to a compressed archive file format.
-
-```javascript
-sharp('input.tiff')
-  .tile({
-    size: 512
-  })
-  .toFile('output.dzi', function(err, info) {
-    // output.dzi is the Deep Zoom XML definition
-    // output_files contains 512x512 tiles grouped by zoom level
-  });
-```
-
-#### withoutChromaSubsampling()
-
-Disable the use of [chroma subsampling](http://en.wikipedia.org/wiki/Chroma_subsampling) with JPEG output (4:4:4).
-
-This can improve colour representation at higher quality settings (90+),
-but usually increases output file size and typically reduces performance by 25%.
-
-The default behaviour is to use chroma subsampling (4:2:0).
-
-#### compressionLevel(compressionLevel)
-
-An advanced setting for the _zlib_ compression level of the lossless PNG output format. The default level is `6`.
-
-`compressionLevel` is a Number between 0 and 9.
-
-#### withoutAdaptiveFiltering()
-
-An advanced setting to disable adaptive row filtering for the lossless PNG output format.
-
-#### trellisQuantisation() / trellisQuantization()
-
-_Requires libvips to have been compiled with mozjpeg support_
-
-An advanced setting to apply the use of
-[trellis quantisation](http://en.wikipedia.org/wiki/Trellis_quantization) with JPEG output.
-Reduces file size and slightly increases relative quality at the cost of increased compression time.
-
-#### overshootDeringing()
-
-_Requires libvips to have been compiled with mozjpeg support_
-
-An advanced setting to reduce the effects of
-[ringing](http://en.wikipedia.org/wiki/Ringing_%28signal%29) in JPEG output,
-in particular where black text appears on a white background (or vice versa).
-
-#### optimiseScans() / optimizeScans()
-
-_Requires libvips to have been compiled with mozjpeg support_
-
-An advanced setting for progressive (interlace) JPEG output.
-Calculates which spectrum of DCT coefficients uses the fewest bits.
-Usually reduces file size at the cost of increased compression time.
-
-### Attributes
-
-#### format
-
-An Object containing nested boolean values
-representing the available input and output formats/methods,
-for example:
-
-```javascript
-> console.dir(sharp.format);
-
-{ jpeg: { id: 'jpeg',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: true, buffer: true, stream: true } },
-  png: { id: 'png',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: true, buffer: true, stream: true } },
-  webp: { id: 'webp',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: true, buffer: true, stream: true } },
-  tiff: { id: 'tiff',
-    input: { file: true, buffer: true, stream: true },
-    output: { file: true, buffer: false, stream: false } },
-  raw: { id: 'raw',
-    input: { file: false, buffer: false, stream: false },
-    output: { file: false, buffer: true, stream: true } } }
-```
-
-#### queue
-
-An EventEmitter that emits a `change` event when a task is either:
-
-* queued, waiting for _libuv_ to provide a worker thread
-* complete
-
-```javascript
-sharp.queue.on('change', function(queueLength) {
-  console.log('Queue contains ' + queueLength + ' task(s)');
-});
-```
-
-#### versions
-
-An Object containing the version numbers of libvips and, on Linux, its dependencies.
-
-```javascript
-console.log(sharp.versions);
-```
-
-### Utilities
-
-#### sharp.cache([options])
-
-If `options` is provided, sets the limits of _libvips'_ operation cache.
-
-* `options.memory` is the maximum memory in MB to use for this cache, with a default value of 50
-* `options.files` is the maximum number of files to hold open, with a default value of 20
-* `options.items` is the maximum number of operations to cache, with a default value of 100
-
-`options` can also be a boolean, where `true` enables the default cache settings and `false` disables all caching.
-
-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.
-
-```javascript
-var stats = sharp.cache();
-```
-
-```javascript
-sharp.cache( { items: 200 } );
-sharp.cache( { files: 0 } );
-sharp.cache(false);
-```
-
-#### sharp.concurrency([threads])
-
-`threads`, if provided, is the Number of threads _libvips'_ should create for processing each image. The default value is the number of CPU cores. A value of `0` will reset to this default.
-
-This method always returns the current concurrency.
-
-```javascript
-var threads = sharp.concurrency(); // 4
-sharp.concurrency(2); // 2
-sharp.concurrency(0); // 4
-```
-
-The maximum number of images that can be processed in parallel is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
-
-#### sharp.counters()
-
-Provides access to internal task counters.
-
-* `queue` is the number of tasks this module has queued waiting for _libuv_ to provide a worker thread from its pool.
-* `process` is the number of resize tasks currently being processed.
-
-```javascript
-var counters = sharp.counters(); // { queue: 2, process: 4 }
-```
-
-#### sharp.simd([enable])
-
-_Requires libvips to have been compiled with liborc support_
-
-Improves the performance of `resize`, `blur` and `sharpen` operations
-by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM NEON.
-
-* `enable`, if present, is a boolean where `true` enables and `false` disables the use of SIMD.
-
-This method always returns the current state.
-
-This feature is currently disabled by default
-but future versions may enable it by default.
-
-When enabled, versions of liborc prior to 0.4.24
-and versions of libvips prior to 8.2.0
-have been known to crash under heavy load.
-
-```javascript
-var simd = sharp.simd();
-// simd is `true` if SIMD is currently enabled
-```
-
-```javascript
-var simd = sharp.simd(true);
-// attempts to enable the use of SIMD, returning true if available
-```

docs/changelog.md

@@ -1,5 +1,69 @@
 # Changelog
 
+### v0.17 - "*quill*"
+
+Requires libvips v8.4.2.
+
+#### v0.17.2 - 11<sup>th</sup> February 2017
+
+* Ensure Readable side of Stream can start flowing after Writable side has finished.
+  [#671](https://github.com/lovell/sharp/issues/671)
+  [@danhaller](https://github.com/danhaller)
+
+* Expose WebP alpha quality, lossless and near-lossless output options.
+  [#685](https://github.com/lovell/sharp/pull/685)
+  [@rnanwani](https://github.com/rnanwani)
+
+#### v0.17.1 - 15<sup>th</sup> January 2017
+
+* Improve error messages for invalid parameters.
+  [@spikeon](https://github.com/spikeon)
+  [#644](https://github.com/lovell/sharp/pull/644)
+
+* Simplify expression for finding vips-cpp libdir.
+  [#656](https://github.com/lovell/sharp/pull/656)
+
+* Allow HTTPS-over-HTTP proxy when downloading pre-compiled dependencies.
+  [@wangzhiwei1888](https://github.com/wangzhiwei1888)
+  [#679](https://github.com/lovell/sharp/issues/679)
+
+#### v0.17.0 - 11<sup>th</sup> December 2016
+
+* Drop support for versions of Node prior to v4.
+
+* Deprecate the following output format "option" functions:
+    quality, progressive, compressionLevel, withoutAdaptiveFiltering,
+    withoutChromaSubsampling, trellisQuantisation, trellisQuantization,
+    overshootDeringing, optimiseScans and optimizeScans.
+  Access to these is now via output format functions, for example `quality(n)`
+    is now `jpeg({quality: n})` and/or `webp({quality: n})`.
+
+* Autoconvert GIF and SVG input to PNG output if no other format is specified.
+
+* Expose libvips' "centre" resize option to mimic \*magick's +0.5px convention.
+  [#568](https://github.com/lovell/sharp/issues/568)
+
+* Ensure support for embedded base64 PNG and JPEG images within an SVG.
+  [#601](https://github.com/lovell/sharp/issues/601)
+  [@dynamite-ready](https://github.com/dynamite-ready)
+
+* Ensure premultiply operation occurs before box filter shrink.
+  [#605](https://github.com/lovell/sharp/issues/605)
+  [@CmdrShepardsPie](https://github.com/CmdrShepardsPie)
+  [@teroparvinen](https://github.com/teroparvinen)
+
+* Add support for PNG and WebP tile-based output formats (in addition to JPEG).
+  [#622](https://github.com/lovell/sharp/pull/622)
+  [@ppaskaris](https://github.com/ppaskaris)
+
+* Allow use of extend with greyscale input.
+  [#623](https://github.com/lovell/sharp/pull/623)
+  [@ppaskaris](https://github.com/ppaskaris)
+
+* Allow non-RGB input to embed/extend onto background with an alpha channel.
+  [#646](https://github.com/lovell/sharp/issues/646)
+  [@DaGaMs](https://github.com/DaGaMs)
+
 ### v0.16 - "*pencil*"
 
 Requires libvips v8.3.3

docs/index.md

@@ -94,12 +94,15 @@ the help and code contributions of the following people:
 * [Kleis Auke Wolthuizen](https://github.com/kleisauke)
 * [Matt Hirsch](https://github.com/mhirsch)
 * [Rahul Nanwani](https://github.com/rnanwani)
+* [Matthias Thoemmes](https://github.com/cmtt)
+* [Patrick Paskaris](https://github.com/ppaskaris)
+* [Jérémy Lal](https://github.com/kapouer)
 
 Thank you!
 
 ### Licence
 
-Copyright 2013, 2014, 2015, 2016 Lovell Fuller and contributors.
+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.

docs/install.md

@@ -4,8 +4,13 @@
 npm install sharp
 ```
 
+```sh
+yarn add sharp
+```
+
 ### Prerequisites
 
+* Node v4+
 * 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
 
@@ -14,7 +19,7 @@ npm install sharp
 [![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)
 
-libvips and its dependencies are fetched and stored within `node_modules/sharp/lib` during `npm install`.
+libvips and its dependencies are fetched and stored within `node_modules/sharp/vendor` during `npm install`.
 This involves an automated HTTPS download of approximately 6.5MB.
 
 Most recent Linux-based operating systems with glibc running on x64 and ARMv6+ CPUs should "just work", e.g.:
@@ -39,15 +44,9 @@ and `LD_LIBRARY_PATH` at runtime.
 This allows the use of newer versions of libvips with older versions of sharp.
 
 For 32-bit Intel CPUs and older Linux-based operating systems such as Centos 6,
-a system-wide installation of the most suitable version of
-libvips and its dependencies can be achieved by running
-the following command as a user with `sudo` access
-(requires `curl` and `pkg-config`):
+it is recommended to install a system-wide installation of libvips from source:
 
-```sh
-# WARNING: This script is deprecated. You probably don't need to run it. Please read above.
-curl -s https://raw.githubusercontent.com/lovell/sharp/master/preinstall.sh | sudo bash -
-```
+https://github.com/jcupitt/libvips#building-libvips-from-a-source-tarball
 
 For Linux-based operating systems such as Alpine that use musl libc,
 the smaller stack size means libvips' cache should be disabled
@@ -57,8 +56,8 @@ via `sharp.cache(false)` to avoid a stack overflow.
 
 [![OS X 10.9.5 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/lib` during `npm install`.
-This involves an automated HTTPS download of approximately 6.5MB.
+libvips and its dependencies are fetched and stored within `node_modules/sharp/vendor` during `npm install`.
+This involves an automated HTTPS download of approximately 6.3MB.
 
 To use your own 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
@@ -68,7 +67,7 @@ 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` during `npm install`.
+libvips and its dependencies are fetched and stored within `node_modules\sharp\vendor` during `npm install`.
 This involves an automated HTTPS download of approximately 9MB.
 
 Only 64-bit (x64) `node.exe` is supported.
@@ -136,6 +135,11 @@ You can now download your deployment ZIP using `scp` and upload it to Lambda. Be
 * [gulp-responsive](https://www.npmjs.com/package/gulp-responsive)
 * [grunt-sharp](https://www.npmjs.com/package/grunt-sharp)
 
+
+### CLI tools
+
+* [sharp-cli](https://www.npmjs.com/package/sharp-cli)
+
 ### Security
 
 Many users of this module process untrusted, user-supplied images,

docs/performance.md

@@ -2,42 +2,42 @@
 
 ### Test environment
 
-* AWS EC2 [c4.xlarge](http://aws.amazon.com/ec2/instance-types/#c4) (4x E5-2666 v3 @ 2.90GHz)
-* Amazon Linux AMI 2016.03.1 (HVM), SSD Volume Type
-* Node.js v6.2.0
+* 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
 
 ### The contenders
 
-* [jimp](https://www.npmjs.com/package/jimp) v0.2.24 - Image processing in pure JavaScript. Bilinear interpolation only.
-* [lwip](https://www.npmjs.com/package/lwip) v0.0.9 - Wrapper around CImg, compiles dependencies from source.
-* [imagemagick-native](https://www.npmjs.com/package/imagemagick-native) v1.9.2 - Wrapper around libmagick++, supports Buffers only.
+* [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.
+* [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) v1.22.0 - Fully featured wrapper around GraphicsMagick's `gm` command line utility.
-* sharp v0.15.0 / libvips v8.3.1 - Caching within libvips disabled to ensure a fair comparison.
+* [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.
 
 ### The task
 
 Decompress a 2725x2225 JPEG image,
-resize to 720x480 using Lanczos 3 resampling (where available),
-then compress to JPEG.
+resize to 720x588 using Lanczos 3 resampling (where available),
+then compress to JPEG at a "quality" setting of 80.
 
 ### Results
 
 | Module             | Input  | Output | Ops/sec | Speed-up |
 | :----------------- | :----- | :----- | ------: | -------: |
-| jimp (bilinear)    | file   | file   |    0.94 |      1.0 |
-| jimp (bilinear)    | buffer | buffer |    0.98 |      1.0 |
-| lwip               | file   | file   |    1.14 |      1.2 |
-| lwip               | buffer | buffer |    1.14 |      1.2 |
-| imagemagick-native | buffer | buffer |    1.66 |      1.8 |
-| imagemagick        | file   | file   |    5.08 |      5.4 |
-| gm                 | buffer | buffer |    5.43 |      5.7 |
-| gm                 | file   | file   |    5.46 |      5.8 |
-| sharp              | stream | stream |   26.52 |     28.2 |
-| sharp              | file   | file   |   28.16 |     30.0 |
-| sharp              | file   | buffer |   28.27 |     30.1 |
-| sharp              | buffer | file   |   28.42 |     30.2 |
-| sharp              | buffer | buffer |   28.42 |     30.2 |
+| 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 |
 
 Greater libvips performance can be expected with caching enabled (default)
 and using 8+ core machines, especially those with larger L1/L2 CPU caches.

lib/channel.js

@@ -0,0 +1,113 @@
+'use strict';
+
+const is = require('./is');
+
+/**
+ * Boolean operations for bandbool.
+ * @private
+ */
+const bool = {
+  and: 'and',
+  or: 'or',
+  eor: 'eor'
+};
+
+/**
+ * Extract a single channel from a multi-channel image.
+ *
+ * @example
+ * sharp(input)
+ *   .extractChannel('green')
+ *   .toFile('input_green.jpg', function(err, info) {
+ *     // info.channels === 1
+ *     // input_green.jpg contains the green channel of the input image
+ *    });
+ *
+ * @param {Number|String} channel - zero-indexed band number to extract, or `red`, `green` or `blue` as alternative to `0`, `1` or `2` respectively.
+ * @returns {Sharp}
+ * @throws {Error} Invalid channel
+ */
+const extractChannel = function extractChannel (channel) {
+  if (channel === 'red') {
+    channel = 0;
+  } else if (channel === 'green') {
+    channel = 1;
+  } else if (channel === 'blue') {
+    channel = 2;
+  }
+  if (is.integer(channel) && is.inRange(channel, 0, 4)) {
+    this.options.extractChannel = channel;
+  } else {
+    throw new Error('Cannot extract invalid channel ' + channel);
+  }
+  return this;
+};
+
+/**
+ * Join one or more channels to the image.
+ * The meaning of the added channels depends on the output colourspace, set with `toColourspace()`.
+ * By default the output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+ * Channel ordering follows vips convention:
+ * - sRGB: 0: Red, 1: Green, 2: Blue, 3: Alpha.
+ * - CMYK: 0: Magenta, 1: Cyan, 2: Yellow, 3: Black, 4: Alpha.
+ *
+ * Buffers may be any of the image formats supported by sharp: JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data.
+ * For raw pixel input, the `options` object should contain a `raw` attribute, which follows the format of the attribute of the same name in the `sharp()` constructor.
+ *
+ * @param {Array<String|Buffer>|String|Buffer} images - one or more images (file paths, Buffers).
+ * @param {Object} options - image options, see `sharp()` constructor.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const joinChannel = function joinChannel (images, options) {
+  if (Array.isArray(images)) {
+    images.forEach(function (image) {
+      this.options.joinChannelIn.push(this._createInputDescriptor(image, options));
+    }, this);
+  } else {
+    this.options.joinChannelIn.push(this._createInputDescriptor(images, options));
+  }
+  return this;
+};
+
+/**
+ * Perform a bitwise boolean operation on all input image channels (bands) to produce a single channel output image.
+ *
+ * @example
+ * sharp('3-channel-rgb-input.png')
+ *   .bandbool(sharp.bool.and)
+ *   .toFile('1-channel-output.png', function (err, info) {
+ *     // The output will be a single channel image where each pixel `P = R & G & B`.
+ *     // If `I(1,1) = [247, 170, 14] = [0b11110111, 0b10101010, 0b00001111]`
+ *     // then `O(1,1) = 0b11110111 & 0b10101010 & 0b00001111 = 0b00000010 = 2`.
+ *   });
+ *
+ * @param {String} boolOp - one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const bandbool = function bandbool (boolOp) {
+  if (is.string(boolOp) && is.inArray(boolOp, ['and', 'or', 'eor'])) {
+    this.options.bandBoolOp = boolOp;
+  } else {
+    throw new Error('Invalid bandbool operation ' + boolOp);
+  }
+  return this;
+};
+
+/**
+ * Decorate the Sharp prototype with channel-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  // Public instance functions
+  [
+    extractChannel,
+    joinChannel,
+    bandbool
+  ].forEach(function (f) {
+    Sharp.prototype[f.name] = f;
+  });
+  // Class attributes
+  Sharp.bool = bool;
+};

lib/colour.js

@@ -0,0 +1,108 @@
+'use strict';
+
+const color = require('color');
+const is = require('./is');
+
+/**
+ * Colourspaces.
+ * @private
+ */
+const colourspace = {
+  multiband: 'multiband',
+  'b-w': 'b-w',
+  bw: 'b-w',
+  cmyk: 'cmyk',
+  srgb: 'srgb'
+};
+
+/**
+ * Set the background for the `embed`, `flatten` and `extend` operations.
+ * The default background is `{r: 0, g: 0, b: 0, alpha: 1}`, black without transparency.
+ *
+ * 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).
+ *
+ * @param {String|Object} rgba - parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameter
+ */
+const background = function background (rgba) {
+  const colour = color(rgba);
+  this.options.background = [
+    colour.red(),
+    colour.green(),
+    colour.blue(),
+    Math.round(colour.alpha() * 255)
+  ];
+  return this;
+};
+
+/**
+ * Convert to 8-bit greyscale; 256 shades of grey.
+ * This is a linear operation. If the input image is in a non-linear colour space such as sRGB, use `gamma()` with `greyscale()` for the best results.
+ * By default the output image will be web-friendly sRGB and contain three (identical) color channels.
+ * This may be overridden by other sharp operations such as `toColourspace('b-w')`,
+ * which will produce an output image containing one color channel.
+ * An alpha channel may be present, and will be unchanged by the operation.
+ * @param {Boolean} [greyscale=true]
+ * @returns {Sharp}
+ */
+const greyscale = function greyscale (greyscale) {
+  this.options.greyscale = is.bool(greyscale) ? greyscale : true;
+  return this;
+};
+
+/**
+ * Alternative spelling of `greyscale`.
+ * @param {Boolean} [grayscale=true]
+ * @returns {Sharp}
+ */
+const grayscale = function grayscale (grayscale) {
+  return this.greyscale(grayscale);
+};
+
+/**
+ * Set the output colourspace.
+ * By default output image will be web-friendly sRGB, with additional channels interpreted as alpha channels.
+ * @param {String} [colourspace] - output colourspace e.g. `srgb`, `rgb`, `cmyk`, `lab`, `b-w` [...](https://github.com/jcupitt/libvips/blob/master/libvips/iofuncs/enumtypes.c#L568)
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const toColourspace = function toColourspace (colourspace) {
+  if (!is.string(colourspace)) {
+    throw new Error('Invalid output colourspace ' + colourspace);
+  }
+  this.options.colourspace = colourspace;
+  return this;
+};
+
+/**
+ * Alternative spelling of `toColourspace`.
+ * @param {String} [colorspace] - output colorspace.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const toColorspace = function toColorspace (colorspace) {
+  return this.toColourspace(colorspace);
+};
+
+/**
+ * Decorate the Sharp prototype with colour-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  // Public instance functions
+  [
+    background,
+    greyscale,
+    grayscale,
+    toColourspace,
+    toColorspace
+  ].forEach(function (f) {
+    Sharp.prototype[f.name] = f;
+  });
+  // Class attributes
+  Sharp.colourspace = colourspace;
+  Sharp.colorspace = colourspace;
+};

lib/composite.js

@@ -0,0 +1,92 @@
+'use strict';
+
+const is = require('./is');
+
+/**
+ * Overlay (composite) an image over the processed (resized, extracted etc.) image.
+ *
+ * The overlay image must be the same size or smaller than the processed image.
+ * If both `top` and `left` options are provided, they take precedence over `gravity`.
+ *
+ * @example
+ * sharp('input.png')
+ *   .rotate(180)
+ *   .resize(300)
+ *   .flatten()
+ *   .background('#ff6600')
+ *   .overlayWith('overlay.png', { gravity: sharp.gravity.southeast } )
+ *   .sharpen()
+ *   .withMetadata()
+ *   .quality(90)
+ *   .webp()
+ *   .toBuffer()
+ *   .then(function(outputBuffer) {
+ *     // outputBuffer contains upside down, 300px wide, alpha channel flattened
+ *     // onto orange background, composited with overlay.png with SE gravity,
+ *     // sharpened, with metadata, 90% quality WebP image data. Phew!
+ *   });
+ *
+ * @param {(Buffer|String)} overlay - Buffer containing image data or String containing the path to an image file.
+ * @param {Object} [options]
+ * @param {String} [options.gravity='centre'] - gravity at which to place the overlay.
+ * @param {Number} [options.top] - the pixel offset from the top edge.
+ * @param {Number} [options.left] - the pixel offset from the left edge.
+ * @param {Boolean} [options.tile=false] - set to true to repeat the overlay image across the entire image with the given `gravity`.
+ * @param {Boolean} [options.cutout=false] - set to true to apply only the alpha channel of the overlay image to the input image, giving the appearance of one image being cut out of another.
+ * @param {Object} [options.raw] - describes overlay when using raw pixel data.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const overlayWith = function overlayWith (overlay, options) {
+  this.options.overlay = this._createInputDescriptor(overlay, options, {
+    allowStream: false
+  });
+  if (is.object(options)) {
+    if (is.defined(options.tile)) {
+      if (is.bool(options.tile)) {
+        this.options.overlayTile = options.tile;
+      } else {
+        throw new Error('Invalid overlay tile ' + options.tile);
+      }
+    }
+    if (is.defined(options.cutout)) {
+      if (is.bool(options.cutout)) {
+        this.options.overlayCutout = options.cutout;
+      } else {
+        throw new Error('Invalid overlay cutout ' + options.cutout);
+      }
+    }
+    if (is.defined(options.left) || is.defined(options.top)) {
+      if (
+        is.integer(options.left) && is.inRange(options.left, 0, this.constructor.maximum.width) &&
+        is.integer(options.top) && is.inRange(options.top, 0, this.constructor.maximum.height)
+      ) {
+        this.options.overlayXOffset = options.left;
+        this.options.overlayYOffset = options.top;
+      } else {
+        throw new Error('Invalid overlay left ' + options.left + ' and/or top ' + options.top);
+      }
+    }
+    if (is.defined(options.gravity)) {
+      if (is.integer(options.gravity) && is.inRange(options.gravity, 0, 8)) {
+        this.options.overlayGravity = options.gravity;
+      } else if (is.string(options.gravity) && is.integer(this.constructor.gravity[options.gravity])) {
+        this.options.overlayGravity = this.constructor.gravity[options.gravity];
+      } else {
+        throw new Error('Unsupported overlay gravity ' + options.gravity);
+      }
+    }
+  }
+  return this;
+};
+
+/**
+ * Decorate the Sharp prototype with composite-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  Sharp.prototype.overlayWith = overlayWith;
+};

lib/constructor.js

@@ -0,0 +1,209 @@
+'use strict';
+
+const path = require('path');
+const util = require('util');
+const stream = require('stream');
+const events = require('events');
+const semver = require('semver');
+const sharp = require('../build/Release/sharp.node');
+
+// Versioning
+let versions = {
+  vips: sharp.libvipsVersion()
+};
+(function () {
+  // Does libvips meet minimum requirement?
+  const libvipsVersionMin = require('../package.json').config.libvips;
+  /* istanbul ignore if */
+  if (semver.lt(versions.vips, libvipsVersionMin)) {
+    throw new Error('Found libvips ' + versions.vips + ' but require at least ' + libvipsVersionMin);
+  }
+  // Include versions of dependencies, if present
+  try {
+    versions = require('../vendor/lib/versions.json');
+  } catch (err) {}
+})();
+
+/**
+ * @class Sharp
+ *
+ * Constructor factory to create an instance of `sharp`, to which further methods are chained.
+ *
+ * JPEG, PNG or WebP format image data can be streamed out from this object.
+ * When using Stream based output, derived attributes are available from the `info` event.
+ *
+ * Implements the [stream.Duplex](http://nodejs.org/api/stream.html#stream_class_stream_duplex) class.
+ *
+ * @example
+ * sharp('input.jpg')
+ *   .resize(300, 200)
+ *   .toFile('output.jpg', function(err) {
+ *     // output.jpg is a 300 pixels wide and 200 pixels high image
+ *     // containing a scaled and cropped version of input.jpg
+ *   });
+ *
+ * @example
+ * // Read image data from readableStream,
+ * // resize to 300 pixels wide,
+ * // emit an 'info' event with calculated dimensions
+ * // and finally write image data to writableStream
+ * var transformer = sharp()
+ *   .resize(300)
+ *   .on('info', function(info) {
+ *     console.log('Image height is ' + info.height);
+ *   });
+ * readableStream.pipe(transformer).pipe(writableStream);
+ *
+ * @param {(Buffer|String)} [input] - if present, can be
+ *  a Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
+ *  a String containing the path to an JPEG, PNG, WebP, GIF, SVG or TIFF image file.
+ *  JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data can be streamed into the object when null or undefined.
+ * @param {Object} [options] - if present, is an Object with optional attributes.
+ * @param {Number} [options.density=72] - integral number representing the DPI for vector images.
+ * @param {Object} [options.raw] - describes raw pixel image data. See `raw()` for pixel ordering.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const Sharp = function (input, options) {
+  if (!(this instanceof Sharp)) {
+    return new Sharp(input, options);
+  }
+  stream.Duplex.call(this);
+  this.options = {
+    // input options
+    sequentialRead: false,
+    limitInputPixels: maximum.pixels,
+    // ICC profiles
+    iccProfilePath: path.join(__dirname, 'icc') + path.sep,
+    // resize options
+    topOffsetPre: -1,
+    leftOffsetPre: -1,
+    widthPre: -1,
+    heightPre: -1,
+    topOffsetPost: -1,
+    leftOffsetPost: -1,
+    widthPost: -1,
+    heightPost: -1,
+    width: -1,
+    height: -1,
+    canvas: 'crop',
+    crop: 0,
+    angle: 0,
+    rotateBeforePreExtract: false,
+    flip: false,
+    flop: false,
+    extendTop: 0,
+    extendBottom: 0,
+    extendLeft: 0,
+    extendRight: 0,
+    withoutEnlargement: false,
+    kernel: 'lanczos3',
+    interpolator: 'bicubic',
+    centreSampling: false,
+    // operations
+    background: [0, 0, 0, 255],
+    flatten: false,
+    negate: false,
+    blurSigma: 0,
+    sharpenSigma: 0,
+    sharpenFlat: 1,
+    sharpenJagged: 2,
+    threshold: 0,
+    thresholdGrayscale: true,
+    trimTolerance: 0,
+    gamma: 0,
+    greyscale: false,
+    normalise: 0,
+    booleanBufferIn: null,
+    booleanFileIn: '',
+    joinChannelIn: [],
+    extractChannel: -1,
+    colourspace: 'srgb',
+    // overlay
+    overlayGravity: 0,
+    overlayXOffset: -1,
+    overlayYOffset: -1,
+    overlayTile: false,
+    overlayCutout: false,
+    // output
+    fileOut: '',
+    formatOut: 'input',
+    streamOut: false,
+    withMetadata: false,
+    withMetadataOrientation: -1,
+    // output format
+    jpegQuality: 80,
+    jpegProgressive: false,
+    jpegChromaSubsampling: '4:2:0',
+    jpegTrellisQuantisation: false,
+    jpegOvershootDeringing: false,
+    jpegOptimiseScans: false,
+    pngProgressive: false,
+    pngCompressionLevel: 6,
+    pngAdaptiveFiltering: true,
+    webpQuality: 80,
+    webpAlphaQuality: 100,
+    webpLossless: false,
+    webpNearLossless: false,
+    tiffQuality: 80,
+    tileSize: 256,
+    tileOverlap: 0,
+    // Function to notify of queue length changes
+    queueListener: function (queueLength) {
+      queue.emit('change', queueLength);
+    }
+  };
+  this.options.input = this._createInputDescriptor(input, options, { allowStream: true });
+  return this;
+};
+util.inherits(Sharp, stream.Duplex);
+
+/**
+ * Pixel limits.
+ * @member
+ * @private
+ */
+const maximum = {
+  width: 0x3FFF,
+  height: 0x3FFF,
+  pixels: Math.pow(0x3FFF, 2)
+};
+Sharp.maximum = maximum;
+
+/**
+ * An EventEmitter that emits a `change` event when a task is either:
+ * - queued, waiting for _libuv_ to provide a worker thread
+ * - complete
+ * @member
+ * @example
+ * sharp.queue.on('change', function(queueLength) {
+ *   console.log('Queue contains ' + queueLength + ' task(s)');
+ * });
+ */
+const queue = new events.EventEmitter();
+Sharp.queue = queue;
+
+/**
+ * An Object containing nested boolean values representing the available input and output formats/methods.
+ * @example
+ * console.log(sharp.format());
+ * @returns {Object}
+ */
+Sharp.format = sharp.format();
+
+/**
+ * An Object containing the version numbers of libvips and its dependencies.
+ * @member
+ * @example
+ * console.log(sharp.versions);
+ */
+Sharp.versions = versions;
+
+/**
+ * Export constructor.
+ * @private
+ */
+module.exports = Sharp;

lib/index.js

@@ -0,0 +1,17 @@
+'use strict';
+
+const Sharp = require('./constructor');
+[
+  'input',
+  'resize',
+  'composite',
+  'operation',
+  'colour',
+  'channel',
+  'output',
+  'utility'
+].forEach(function (decorator) {
+  require('./' + decorator)(Sharp);
+});
+
+module.exports = Sharp;

lib/input.js

@@ -0,0 +1,258 @@
+'use strict';
+
+const util = require('util');
+const is = require('./is');
+const sharp = require('../build/Release/sharp.node');
+
+/**
+ * Create Object containing input and input-related options.
+ * @private
+ */
+const _createInputDescriptor = function _createInputDescriptor (input, inputOptions, containerOptions) {
+  const inputDescriptor = {};
+  if (is.string(input)) {
+    // filesystem
+    inputDescriptor.file = input;
+  } else if (is.buffer(input)) {
+    // Buffer
+    inputDescriptor.buffer = input;
+  } else if (!is.defined(input) && is.object(containerOptions) && containerOptions.allowStream) {
+    // Stream
+    inputDescriptor.buffer = [];
+  } else {
+    throw new Error('Unsupported input ' + typeof input);
+  }
+  if (is.object(inputOptions)) {
+    // Density
+    if (is.defined(inputOptions.density)) {
+      if (is.integer(inputOptions.density) && is.inRange(inputOptions.density, 1, 2400)) {
+        inputDescriptor.density = inputOptions.density;
+      } else {
+        throw new Error('Invalid density (1 to 2400) ' + inputOptions.density);
+      }
+    }
+    // Raw pixel input
+    if (is.defined(inputOptions.raw)) {
+      if (
+        is.object(inputOptions.raw) &&
+        is.integer(inputOptions.raw.width) && is.inRange(inputOptions.raw.width, 1, this.constructor.maximum.width) &&
+        is.integer(inputOptions.raw.height) && is.inRange(inputOptions.raw.height, 1, this.constructor.maximum.height) &&
+        is.integer(inputOptions.raw.channels) && is.inRange(inputOptions.raw.channels, 1, 4)
+      ) {
+        inputDescriptor.rawWidth = inputOptions.raw.width;
+        inputDescriptor.rawHeight = inputOptions.raw.height;
+        inputDescriptor.rawChannels = inputOptions.raw.channels;
+      } else {
+        throw new Error('Expected width, height and channels for raw pixel input');
+      }
+    }
+  } else if (is.defined(inputOptions)) {
+    throw new Error('Invalid input options ' + inputOptions);
+  }
+  return inputDescriptor;
+};
+
+/**
+ * Handle incoming Buffer chunk on Writable Stream.
+ * @private
+ * @param {Buffer} chunk
+ * @param {String} encoding - unused
+ * @param {Function} callback
+ */
+const _write = function _write (chunk, encoding, callback) {
+  /* istanbul ignore else */
+  if (Array.isArray(this.options.input.buffer)) {
+    /* istanbul ignore else */
+    if (is.buffer(chunk)) {
+      if (this.options.input.buffer.length === 0) {
+        const that = this;
+        this.on('finish', function () {
+          that.streamInFinished = true;
+        });
+      }
+      this.options.input.buffer.push(chunk);
+      callback();
+    } else {
+      callback(new Error('Non-Buffer data on Writable Stream'));
+    }
+  } else {
+    callback(new Error('Unexpected data on Writable Stream'));
+  }
+};
+
+/**
+ * Flattens the array of chunks accumulated in input.buffer.
+ * @private
+ */
+const _flattenBufferIn = function _flattenBufferIn () {
+  if (this._isStreamInput()) {
+    this.options.input.buffer = Buffer.concat(this.options.input.buffer);
+  }
+};
+
+/**
+ * Are we expecting Stream-based input?
+ * @private
+ * @returns {Boolean}
+ */
+const _isStreamInput = function _isStreamInput () {
+  return Array.isArray(this.options.input.buffer);
+};
+
+/**
+ * Take a "snapshot" of the Sharp instance, returning a new instance.
+ * Cloned instances inherit the input of their parent instance.
+ * This allows multiple output Streams and therefore multiple processing pipelines to share a single input Stream.
+ *
+ * @example
+ * const pipeline = sharp().rotate();
+ * pipeline.clone().resize(800, 600).pipe(firstWritableStream);
+ * pipeline.clone().extract({ left: 20, top: 20, width: 100, height: 100 }).pipe(secondWritableStream);
+ * readableStream.pipe(pipeline);
+ * // firstWritableStream receives auto-rotated, resized readableStream
+ * // secondWritableStream receives auto-rotated, extracted region of readableStream
+ *
+ * @returns {Sharp}
+ */
+const clone = function clone () {
+  const that = this;
+  // Clone existing options
+  const clone = this.constructor.call();
+  util._extend(clone.options, 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');
+  });
+  return clone;
+};
+
+/**
+ * Fast access to image metadata without decoding any compressed image data.
+ * A Promises/A+ promise is returned when `callback` is not provided.
+ *
+ * - `format`: Name of decoder used to decompress image data e.g. `jpeg`, `png`, `webp`, `gif`, `svg`
+ * - `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#L568)
+ * - `channels`: Number of bands e.g. `3` for sRGB, `4` for CMYK
+ * - `density`: Number of pixels per inch (DPI), if present
+ * - `hasProfile`: Boolean indicating the presence of an embedded ICC profile
+ * - `hasAlpha`: Boolean indicating the presence of an alpha transparency channel
+ * - `orientation`: Number value of the EXIF Orientation header, if present
+ * - `exif`: Buffer containing raw EXIF data, if present
+ * - `icc`: Buffer containing raw [ICC](https://www.npmjs.com/package/icc) profile data, if present
+ *
+ * @example
+ * const image = sharp(inputJpg);
+ * image
+ *   .metadata()
+ *   .then(function(metadata) {
+ *     return image
+ *       .resize(Math.round(metadata.width / 2))
+ *       .webp()
+ *       .toBuffer();
+ *   })
+ *   .then(function(data) {
+ *     // data contains a WebP image half the width and height of the original JPEG
+ *   });
+ *
+ * @param {Function} [callback] - called with the arguments `(err, metadata)`
+ * @returns {Promise<Object>|Sharp}
+ */
+const metadata = function metadata (callback) {
+  const that = this;
+  if (is.fn(callback)) {
+    if (this._isStreamInput()) {
+      this.on('finish', function () {
+        that._flattenBufferIn();
+        sharp.metadata(that.options, callback);
+      });
+    } else {
+      sharp.metadata(this.options, callback);
+    }
+    return this;
+  } else {
+    if (this._isStreamInput()) {
+      return new Promise(function (resolve, reject) {
+        that.on('finish', function () {
+          that._flattenBufferIn();
+          sharp.metadata(that.options, function (err, metadata) {
+            if (err) {
+              reject(err);
+            } else {
+              resolve(metadata);
+            }
+          });
+        });
+      });
+    } else {
+      return new Promise(function (resolve, reject) {
+        sharp.metadata(that.options, function (err, metadata) {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(metadata);
+          }
+        });
+      });
+    }
+  }
+};
+
+/**
+ * Do not process input images where the number of pixels (width * height) exceeds this limit.
+ * Assumes image dimensions contained in the input metadata can be trusted.
+ * The default limit is 268402689 (0x3FFF * 0x3FFF) pixels.
+ * @param {(Number|Boolean)} limit - an integral Number of pixels, zero or false to remove limit, true to use default limit.
+ * @returns {Sharp}
+ * @throws {Error} Invalid limit
+*/
+const limitInputPixels = function limitInputPixels (limit) {
+  // if we pass in false we represent the integer as 0 to disable
+  if (limit === false) {
+    limit = 0;
+  } else if (limit === true) {
+    limit = this.constructor.maximum.pixels;
+  }
+  if (is.integer(limit) && limit >= 0) {
+    this.options.limitInputPixels = limit;
+  } else {
+    throw new Error('Invalid pixel limit (0 to ' + this.constructor.maximum.pixels + ') ' + limit);
+  }
+  return this;
+};
+
+/**
+ * An advanced setting that switches the libvips access method to `VIPS_ACCESS_SEQUENTIAL`.
+ * This will reduce memory usage and can improve performance on some systems.
+ * @param {Boolean} [sequentialRead=true]
+ * @returns {Sharp}
+ */
+const sequentialRead = function sequentialRead (sequentialRead) {
+  this.options.sequentialRead = is.bool(sequentialRead) ? sequentialRead : true;
+  return this;
+};
+
+/**
+ * Decorate the Sharp prototype with input-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  [
+    // Private
+    _createInputDescriptor,
+    _write,
+    _flattenBufferIn,
+    _isStreamInput,
+    // Public
+    clone,
+    metadata,
+    limitInputPixels,
+    sequentialRead
+  ].forEach(function (f) {
+    Sharp.prototype[f.name] = f;
+  });
+};

lib/is.js

@@ -0,0 +1,110 @@
+'use strict';
+
+/**
+ * Is this value defined and not null?
+ * @private
+ */
+const defined = function (val) {
+  return typeof val !== 'undefined' && val !== null;
+};
+
+/**
+ * Is this value an object?
+ * @private
+ */
+const object = function (val) {
+  return typeof val === 'object';
+};
+
+/**
+ * Is this value a function?
+ * @private
+ */
+const fn = function (val) {
+  return typeof val === 'function';
+};
+
+/**
+ * Is this value a boolean?
+ * @private
+ */
+const bool = function (val) {
+  return typeof val === 'boolean';
+};
+
+/**
+ * Is this value a Buffer object?
+ * @private
+ */
+const buffer = function (val) {
+  return object(val) && val instanceof Buffer;
+};
+
+/**
+ * Is this value a non-empty string?
+ * @private
+ */
+const string = function (val) {
+  return typeof val === 'string' && val.length > 0;
+};
+
+/**
+ * Is this value a real number?
+ * @private
+ */
+const number = function (val) {
+  return typeof val === 'number' && !Number.isNaN(val);
+};
+
+/**
+ * Is this value an integer?
+ * @private
+ */
+const integer = function (val) {
+  return number(val) && val % 1 === 0;
+};
+
+/**
+ * Is this value within an inclusive given range?
+ * @private
+ */
+const inRange = function (val, min, max) {
+  return val >= min && val <= max;
+};
+
+/**
+ * Is this value within the elements of an array?
+ * @private
+ */
+const inArray = function (val, list) {
+  return list.indexOf(val) !== -1;
+};
+
+/**
+ * Create an Error with a message relating to an invalid parameter.
+ *
+ * @param {String} name - parameter name.
+ * @param {String} expected - description of the type/value/range expected.
+ * @param {*} actual - the value received.
+ * @returns {Error} Containing the formatted message.
+ * @private
+ */
+const invalidParameterError = function (name, expected, actual) {
+  return new Error(
+    `Expected ${expected} for ${name} but received ${actual} of type ${typeof actual}`
+  );
+};
+
+module.exports = {
+  defined: defined,
+  object: object,
+  fn: fn,
+  bool: bool,
+  buffer: buffer,
+  string: string,
+  number: number,
+  integer: integer,
+  inRange: inRange,
+  inArray: inArray,
+  invalidParameterError: invalidParameterError
+};

lib/operation.js

@@ -0,0 +1,431 @@
+'use strict';
+
+const is = require('./is');
+
+/**
+ * Rotate the output image by either an explicit angle
+ * or auto-orient based on the EXIF `Orientation` tag.
+ *
+ * Use this method without angle to determine the angle from EXIF data.
+ * Mirroring is supported and may infer the use of a flip operation.
+ *
+ * The use of `rotate` implies the removal of the EXIF `Orientation` tag, if any.
+ *
+ * Method order is important when both rotating and extracting regions,
+ * for example `rotate(x).extract(y)` will produce a different result to `extract(y).rotate(x)`.
+ *
+ * @example
+ * const pipeline = sharp()
+ *   .rotate()
+ *   .resize(null, 200)
+ *   .toBuffer(function (err, outputBuffer, info) {
+ *     // outputBuffer contains 200px high JPEG image data,
+ *     // auto-rotated using EXIF Orientation tag
+ *     // info.width and info.height contain the dimensions of the resized image
+ *   });
+ * readableStream.pipe(pipeline);
+ *
+ * @param {Number} [angle=auto] 0, 90, 180 or 270.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const rotate = function rotate (angle) {
+  if (!is.defined(angle)) {
+    this.options.angle = -1;
+  } else if (is.integer(angle) && is.inArray(angle, [0, 90, 180, 270])) {
+    this.options.angle = angle;
+  } else {
+    throw new Error('Unsupported angle (0, 90, 180, 270) ' + angle);
+  }
+  return this;
+};
+
+/**
+ * Extract a region of the image.
+ *
+ * - Use `extract` before `resize` for pre-resize extraction.
+ * - Use `extract` after `resize` for post-resize extraction.
+ * - Use `extract` before and after for both.
+ *
+ * @example
+ * sharp(input)
+ *   .extract({ left: left, top: top, width: width, height: height })
+ *   .toFile(output, function(err) {
+ *     // Extract a region of the input image, saving in the same format.
+ *   });
+ * @example
+ * sharp(input)
+ *   .extract({ left: leftOffsetPre, top: topOffsetPre, width: widthPre, height: heightPre })
+ *   .resize(width, height)
+ *   .extract({ left: leftOffsetPost, top: topOffsetPost, width: widthPost, height: heightPost })
+ *   .toFile(output, function(err) {
+ *     // Extract a region, resize, then extract from the resized image
+ *   });
+ *
+ * @param {Object} options
+ * @param {Number} options.left - zero-indexed offset from left edge
+ * @param {Number} options.top - zero-indexed offset from top edge
+ * @param {Number} options.width - dimension of extracted image
+ * @param {Number} options.height - dimension of extracted image
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const extract = function extract (options) {
+  const suffix = this.options.width === -1 && this.options.height === -1 ? 'Pre' : 'Post';
+  ['left', 'top', 'width', 'height'].forEach(function (name) {
+    const value = options[name];
+    if (is.integer(value) && value >= 0) {
+      this.options[name + (name === 'left' || name === 'top' ? 'Offset' : '') + suffix] = value;
+    } else {
+      throw new Error('Non-integer value for ' + name + ' of ' + value);
+    }
+  }, this);
+  // Ensure existing rotation occurs before pre-resize extraction
+  if (suffix === 'Pre' && this.options.angle !== 0) {
+    this.options.rotateBeforePreExtract = true;
+  }
+  return this;
+};
+
+/**
+ * Flip the image about the vertical Y axis. This always occurs after rotation, if any.
+ * The use of `flip` implies the removal of the EXIF `Orientation` tag, if any.
+ * @param {Boolean} [flip=true]
+ * @returns {Sharp}
+ */
+const flip = function flip (flip) {
+  this.options.flip = is.bool(flip) ? flip : true;
+  return this;
+};
+
+/**
+ * Flop the image about the horizontal X axis. This always occurs after rotation, if any.
+ * The use of `flop` implies the removal of the EXIF `Orientation` tag, if any.
+ * @param {Boolean} [flop=true]
+ * @returns {Sharp}
+ */
+const flop = function flop (flop) {
+  this.options.flop = is.bool(flop) ? flop : true;
+  return this;
+};
+
+/**
+ * Sharpen the image.
+ * When used without parameters, performs a fast, mild sharpen of the output image.
+ * When a `sigma` is provided, performs a slower, more accurate sharpen of the L channel in the LAB colour space.
+ * Separate control over the level of sharpening in "flat" and "jagged" areas is available.
+ *
+ * @param {Number} [sigma] - the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+ * @param {Number} [flat=1.0] - the level of sharpening to apply to "flat" areas.
+ * @param {Number} [jagged=2.0] - the level of sharpening to apply to "jagged" areas.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const sharpen = function sharpen (sigma, flat, jagged) {
+  if (!is.defined(sigma)) {
+    // No arguments: default to mild sharpen
+    this.options.sharpenSigma = -1;
+  } else if (is.bool(sigma)) {
+    // Boolean argument: apply mild sharpen?
+    this.options.sharpenSigma = sigma ? -1 : 0;
+  } else if (is.number(sigma) && is.inRange(sigma, 0.01, 10000)) {
+    // Numeric argument: specific sigma
+    this.options.sharpenSigma = sigma;
+    // Control over flat areas
+    if (is.defined(flat)) {
+      if (is.number(flat) && is.inRange(flat, 0, 10000)) {
+        this.options.sharpenFlat = flat;
+      } else {
+        throw new Error('Invalid sharpen level for flat areas (0.0 - 10000.0) ' + flat);
+      }
+    }
+    // Control over jagged areas
+    if (is.defined(jagged)) {
+      if (is.number(jagged) && is.inRange(jagged, 0, 10000)) {
+        this.options.sharpenJagged = jagged;
+      } else {
+        throw new Error('Invalid sharpen level for jagged areas (0.0 - 10000.0) ' + jagged);
+      }
+    }
+  } else {
+    throw new Error('Invalid sharpen sigma (0.01 - 10000) ' + sigma);
+  }
+  return this;
+};
+
+/**
+ * Blur the image.
+ * When used without parameters, performs a fast, mild blur of the output image.
+ * When a `sigma` is provided, performs a slower, more accurate Gaussian blur.
+ * @param {Number} [sigma] a value between 0.3 and 1000 representing the sigma of the Gaussian mask, where `sigma = 1 + radius / 2`.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const blur = function blur (sigma) {
+  if (!is.defined(sigma)) {
+    // No arguments: default to mild blur
+    this.options.blurSigma = -1;
+  } else if (is.bool(sigma)) {
+    // Boolean argument: apply mild blur?
+    this.options.blurSigma = sigma ? -1 : 0;
+  } else if (is.number(sigma) && is.inRange(sigma, 0.3, 1000)) {
+    // Numeric argument: specific sigma
+    this.options.blurSigma = sigma;
+  } else {
+    throw new Error('Invalid blur sigma (0.3 - 1000.0) ' + sigma);
+  }
+  return this;
+};
+
+/**
+ * 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.
+ *
+ * @example
+ * // Resize to 140 pixels wide, then add 10 transparent pixels
+ * // to the top, left and right edges and 20 to the bottom edge
+ * sharp(input)
+ *   .resize(140)
+ *   .background({r: 0, g: 0, b: 0, alpha: 0})
+ *   .extend({top: 10, bottom: 20, left: 10, right: 10})
+ *   ...
+ *
+ * @param {(Number|Object)} extend - single pixel count to add to all edges or an Object with per-edge counts
+ * @param {Number} [extend.top]
+ * @param {Number} [extend.left]
+ * @param {Number} [extend.bottom]
+ * @param {Number} [extend.right]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+*/
+const extend = function extend (extend) {
+  if (is.integer(extend) && extend > 0) {
+    this.options.extendTop = extend;
+    this.options.extendBottom = extend;
+    this.options.extendLeft = extend;
+    this.options.extendRight = extend;
+  } else if (
+    is.object(extend) &&
+    is.integer(extend.top) && extend.top >= 0 &&
+    is.integer(extend.bottom) && extend.bottom >= 0 &&
+    is.integer(extend.left) && extend.left >= 0 &&
+    is.integer(extend.right) && extend.right >= 0
+  ) {
+    this.options.extendTop = extend.top;
+    this.options.extendBottom = extend.bottom;
+    this.options.extendLeft = extend.left;
+    this.options.extendRight = extend.right;
+  } else {
+    throw new Error('Invalid edge extension ' + extend);
+  }
+  return this;
+};
+
+/**
+ * Merge alpha transparency channel, if any, with `background`.
+ * @param {Boolean} [flatten=true]
+ * @returns {Sharp}
+ */
+const flatten = function flatten (flatten) {
+  this.options.flatten = is.bool(flatten) ? flatten : true;
+  return this;
+};
+
+/**
+ * Trim "boring" pixels from all edges that contain values within a percentage similarity of the top-left pixel.
+ * @param {Number} [tolerance=10] value between 1 and 99 representing the percentage similarity.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const trim = function trim (tolerance) {
+  if (!is.defined(tolerance)) {
+    this.options.trimTolerance = 10;
+  } else if (is.integer(tolerance) && is.inRange(tolerance, 1, 99)) {
+    this.options.trimTolerance = tolerance;
+  } else {
+    throw new Error('Invalid trim tolerance (1 to 99) ' + tolerance);
+  }
+  return this;
+};
+
+/**
+ * Apply a gamma correction by reducing the encoding (darken) pre-resize at a factor of `1/gamma`
+ * then increasing the encoding (brighten) post-resize at a factor of `gamma`.
+ * This can improve the perceived brightness of a resized image in non-linear colour spaces.
+ * JPEG and WebP input images will not take advantage of the shrink-on-load performance optimisation
+ * when applying a gamma correction.
+ * @param {Number} [gamma=2.2] value between 1.0 and 3.0.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const gamma = function gamma (gamma) {
+  if (!is.defined(gamma)) {
+    // Default gamma correction of 2.2 (sRGB)
+    this.options.gamma = 2.2;
+  } else if (is.number(gamma) && is.inRange(gamma, 1, 3)) {
+    this.options.gamma = gamma;
+  } else {
+    throw new Error('Invalid gamma correction (1.0 to 3.0) ' + gamma);
+  }
+  return this;
+};
+
+/**
+ * Produce the "negative" of the image.
+ * @param {Boolean} [negate=true]
+ * @returns {Sharp}
+ */
+const negate = function negate (negate) {
+  this.options.negate = is.bool(negate) ? negate : true;
+  return this;
+};
+
+/**
+ * Enhance output image contrast by stretching its luminance to cover the full dynamic range.
+ * @param {Boolean} [normalise=true]
+ * @returns {Sharp}
+ */
+const normalise = function normalise (normalise) {
+  this.options.normalise = is.bool(normalise) ? normalise : true;
+  return this;
+};
+
+/**
+ * Alternative spelling of normalise.
+ * @param {Boolean} [normalize=true]
+ * @returns {Sharp}
+ */
+const normalize = function normalize (normalize) {
+  return this.normalise(normalize);
+};
+
+/**
+ * Convolve the image with the specified kernel.
+ *
+ * @example
+ * sharp(input)
+ *   .convolve({
+ *     width: 3,
+ *     height: 3,
+ *     kernel: [-1, 0, 1, -2, 0, 2, -1, 0, 1]
+ *   })
+ *   .raw()
+ *   .toBuffer(function(err, data, info) {
+ *     // data contains the raw pixel data representing the convolution
+ *     // of the input image with the horizontal Sobel operator
+ *   });
+ *
+ * @param {Object} kernel
+ * @param {Number} kernel.width - width of the kernel in pixels.
+ * @param {Number} kernel.height - width of the kernel in pixels.
+ * @param {Array<Number>} kernel.kernel - Array of length `width*height` containing the kernel values.
+ * @param {Number} [kernel.scale=sum] - the scale of the kernel in pixels.
+ * @param {Number} [kernel.offset=0] - the offset of the kernel in pixels.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const convolve = function convolve (kernel) {
+  if (!is.object(kernel) || !Array.isArray(kernel.kernel) ||
+      !is.integer(kernel.width) || !is.integer(kernel.height) ||
+      !is.inRange(kernel.width, 3, 1001) || !is.inRange(kernel.height, 3, 1001) ||
+      kernel.height * kernel.width !== kernel.kernel.length
+     ) {
+    // must pass in a kernel
+    throw new Error('Invalid convolution kernel');
+  }
+  // Default scale is sum of kernel values
+  if (!is.integer(kernel.scale)) {
+    kernel.scale = kernel.kernel.reduce(function (a, b) {
+      return a + b;
+    }, 0);
+  }
+  // Clip scale to a minimum value of 1
+  if (kernel.scale < 1) {
+    kernel.scale = 1;
+  }
+  if (!is.integer(kernel.offset)) {
+    kernel.offset = 0;
+  }
+  this.options.convKernel = kernel;
+  return this;
+};
+
+/**
+ * Any pixel value greather than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
+ * @param {Number} [threshold=128] - a value in the range 0-255 representing the level at which the threshold will be applied.
+ * @param {Object} [options]
+ * @param {Boolean} [options.greyscale=true] - convert to single channel greyscale.
+ * @param {Boolean} [options.grayscale=true] - alternative spelling for greyscale.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const threshold = function threshold (threshold, options) {
+  if (!is.defined(threshold)) {
+    this.options.threshold = 128;
+  } else if (is.bool(threshold)) {
+    this.options.threshold = threshold ? 128 : 0;
+  } else if (is.integer(threshold) && is.inRange(threshold, 0, 255)) {
+    this.options.threshold = threshold;
+  } else {
+    throw new Error('Invalid threshold (0 to 255) ' + threshold);
+  }
+  if (!is.object(options) || options.greyscale === true || options.grayscale === true) {
+    this.options.thresholdGrayscale = true;
+  } else {
+    this.options.thresholdGrayscale = false;
+  }
+  return this;
+};
+
+/**
+ * Perform a bitwise boolean operation with operand image.
+ *
+ * This operation creates an output image where each pixel is the result of
+ * the selected bitwise boolean `operation` between the corresponding pixels of the input images.
+ *
+ * @param {Buffer|String} operand - Buffer containing image data or String containing the path to an image file.
+ * @param {String} operator - one of `and`, `or` or `eor` to perform that bitwise operation, like the C logic operators `&`, `|` and `^` respectively.
+ * @param {Object} [options]
+ * @param {Object} [options.raw] - describes operand when using raw pixel data.
+ * @param {Number} [options.raw.width]
+ * @param {Number} [options.raw.height]
+ * @param {Number} [options.raw.channels]
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const boolean = function boolean (operand, operator, options) {
+  this.options.boolean = this._createInputDescriptor(operand, options);
+  if (is.string(operator) && is.inArray(operator, ['and', 'or', 'eor'])) {
+    this.options.booleanOp = operator;
+  } else {
+    throw new Error('Invalid boolean operator ' + operator);
+  }
+  return this;
+};
+
+/**
+ * Decorate the Sharp prototype with operation-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  [
+    rotate,
+    extract,
+    flip,
+    flop,
+    sharpen,
+    blur,
+    extend,
+    flatten,
+    trim,
+    gamma,
+    negate,
+    normalise,
+    normalize,
+    convolve,
+    threshold,
+    boolean
+  ].forEach(function (f) {
+    Sharp.prototype[f.name] = f;
+  });
+};

lib/output.js

@@ -0,0 +1,546 @@
+'use strict';
+
+const util = require('util');
+const is = require('./is');
+const sharp = require('../build/Release/sharp.node');
+
+/**
+ * Write output image data to a file.
+ *
+ * If an explicit output format is not selected, it will be inferred from the extension,
+ * with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
+ * Note that raw pixel data is only supported for buffer output.
+ *
+ * A Promises/A+ promise is returned when `callback` is not provided.
+ *
+ * @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` and `channels`.
+ * @returns {Promise<Object>} - when no callback is provided
+ * @throws {Error} Invalid parameters
+ */
+const toFile = function toFile (fileOut, callback) {
+  if (!fileOut || fileOut.length === 0) {
+    const errOutputInvalid = new Error('Invalid output');
+    if (is.fn(callback)) {
+      callback(errOutputInvalid);
+    } else {
+      return Promise.reject(errOutputInvalid);
+    }
+  } else {
+    if (this.options.input.file === fileOut) {
+      const errOutputIsInput = new Error('Cannot use same file for input and output');
+      if (is.fn(callback)) {
+        callback(errOutputIsInput);
+      } else {
+        return Promise.reject(errOutputIsInput);
+      }
+    } else {
+      this.options.fileOut = fileOut;
+      return this._pipeline(callback);
+    }
+  }
+  return this;
+};
+
+/**
+ * Write output to a Buffer.
+ * JPEG, PNG, WebP, and RAW output are supported.
+ * By default, the format will match the input image, except GIF and SVG input which become PNG output.
+ *
+ * `callback`, if present, gets three arguments `(err, buffer, info)` where:
+ * - `err` is an error message, if any.
+ * - `buffer` is the output image data.
+ * - `info` contains the output image `format`, `size` (bytes), `width`, `height` and `channels`.
+ * A Promises/A+ promise is returned when `callback` is not provided.
+ *
+ * @param {Function} [callback]
+ * @returns {Promise<Buffer>} - when no callback is provided
+ */
+const toBuffer = function toBuffer (callback) {
+  return this._pipeline(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.
+ * @param {Object} [withMetadata]
+ * @param {Number} [withMetadata.orientation] value between 1 and 8, used to update the EXIF `Orientation` tag.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const withMetadata = function withMetadata (withMetadata) {
+  this.options.withMetadata = is.bool(withMetadata) ? withMetadata : true;
+  if (is.object(withMetadata)) {
+    if (is.defined(withMetadata.orientation)) {
+      if (is.integer(withMetadata.orientation) && is.inRange(withMetadata.orientation, 1, 8)) {
+        this.options.withMetadataOrientation = withMetadata.orientation;
+      } else {
+        throw new Error('Invalid orientation (1 to 8) ' + withMetadata.orientation);
+      }
+    }
+  }
+  return this;
+};
+
+/**
+ * Use these JPEG options for output image.
+ * @param {Object} [options] - output options
+ * @param {Number} [options.quality=80] - quality, integer 1-100
+ * @param {Boolean} [options.progressive=false] - use progressive (interlace) scan
+ * @param {String} [options.chromaSubsampling='4:2:0'] - set to '4:4:4' to prevent chroma subsampling when quality <= 90
+ * @param {Boolean} [options.trellisQuantisation=false] - apply trellis quantisation, requires mozjpeg
+ * @param {Boolean} [options.overshootDeringing=false] - apply overshoot deringing, requires mozjpeg
+ * @param {Boolean} [options.optimiseScans=false] - optimise progressive scans, forces progressive, requires mozjpeg
+ * @param {Boolean} [options.optimizeScans=false] - alternative spelling of optimiseScans
+ * @param {Boolean} [options.force=true] - force JPEG output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+const jpeg = function jpeg (options) {
+  if (is.object(options)) {
+    if (is.defined(options.quality)) {
+      if (is.integer(options.quality) && is.inRange(options.quality, 1, 100)) {
+        this.options.jpegQuality = options.quality;
+      } else {
+        throw new Error('Invalid quality (integer, 1-100) ' + options.quality);
+      }
+    }
+    if (is.defined(options.progressive)) {
+      this._setBooleanOption('jpegProgressive', options.progressive);
+    }
+    if (is.defined(options.chromaSubsampling)) {
+      if (is.string(options.chromaSubsampling) && is.inArray(options.chromaSubsampling, ['4:2:0', '4:4:4'])) {
+        this.options.jpegChromaSubsampling = options.chromaSubsampling;
+      } else {
+        throw new Error('Invalid chromaSubsampling (4:2:0, 4:4:4) ' + options.chromaSubsampling);
+      }
+    }
+    options.trellisQuantisation = is.bool(options.trellisQuantization) ? options.trellisQuantization : options.trellisQuantisation;
+    if (is.defined(options.trellisQuantisation)) {
+      this._setBooleanOption('jpegTrellisQuantisation', options.trellisQuantisation);
+    }
+    if (is.defined(options.overshootDeringing)) {
+      this._setBooleanOption('jpegOvershootDeringing', options.overshootDeringing);
+    }
+    options.optimiseScans = is.bool(options.optimizeScans) ? options.optimizeScans : options.optimiseScans;
+    if (is.defined(options.optimiseScans)) {
+      this._setBooleanOption('jpegOptimiseScans', options.optimiseScans);
+      if (options.optimiseScans) {
+        this.options.jpegProgressive = true;
+      }
+    }
+  }
+  return this._updateFormatOut('jpeg', options);
+};
+
+/**
+ * Use these PNG options for output image.
+ * @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 {Boolean} [options.force=true] - force PNG output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+const png = function png (options) {
+  if (is.object(options)) {
+    if (is.defined(options.progressive)) {
+      this._setBooleanOption('pngProgressive', options.progressive);
+    }
+    if (is.defined(options.compressionLevel)) {
+      if (is.integer(options.compressionLevel) && is.inRange(options.compressionLevel, 0, 9)) {
+        this.options.pngCompressionLevel = options.compressionLevel;
+      } else {
+        throw new Error('Invalid compressionLevel (integer, 0-9) ' + options.compressionLevel);
+      }
+    }
+    if (is.defined(options.adaptiveFiltering)) {
+      this._setBooleanOption('pngAdaptiveFiltering', options.adaptiveFiltering);
+    }
+  }
+  return this._updateFormatOut('png', options);
+};
+
+/**
+ * Use these WebP options for output image.
+ * @param {Object} [options] - output options
+ * @param {Number} [options.quality=80] - quality, integer 1-100
+ * @param {Number} [options.alphaQuality=100] - quality of alpha layer, integer 0-100
+ * @param {Boolean} [options.lossless=false] - use lossless compression mode
+ * @param {Boolean} [options.nearLossless=false] - use near_lossless compression mode
+ * @param {Boolean} [options.force=true] - force WebP output, otherwise attempt to use input format
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+const webp = function webp (options) {
+  if (is.object(options) && is.defined(options.quality)) {
+    if (is.integer(options.quality) && is.inRange(options.quality, 1, 100)) {
+      this.options.webpQuality = options.quality;
+    } else {
+      throw new Error('Invalid quality (integer, 1-100) ' + options.quality);
+    }
+  }
+  if (is.object(options) && is.defined(options.alphaQuality)) {
+    if (is.integer(options.alphaQuality) && is.inRange(options.alphaQuality, 1, 100)) {
+      this.options.webpAlphaQuality = options.alphaQuality;
+    } else {
+      throw new Error('Invalid webp alpha quality (integer, 1-100) ' + options.alphaQuality);
+    }
+  }
+  if (is.object(options) && is.defined(options.lossless)) {
+    this._setBooleanOption('webpLossless', options.lossless);
+  }
+  if (is.object(options) && is.defined(options.nearLossless)) {
+    this._setBooleanOption('webpNearLossless', options.nearLossless);
+  }
+  return this._updateFormatOut('webp', options);
+};
+
+/**
+ * Use these TIFF options for output image.
+ * @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
+ * @returns {Sharp}
+ * @throws {Error} Invalid options
+ */
+const tiff = function tiff (options) {
+  if (is.object(options) && is.defined(options.quality)) {
+    if (is.integer(options.quality) && is.inRange(options.quality, 1, 100)) {
+      this.options.tiffQuality = options.quality;
+    } else {
+      throw new Error('Invalid quality (integer, 1-100) ' + options.quality);
+    }
+  }
+  return this._updateFormatOut('tiff', options);
+};
+
+/**
+ * Force output to be raw, uncompressed uint8 pixel data.
+ * @returns {Sharp}
+ */
+const raw = function raw () {
+  return this._updateFormatOut('raw');
+};
+
+/**
+ * Force output to a given format.
+ * @param {(String|Object)} format - as a String or an Object with an 'id' attribute
+ * @param {Object} options - output options
+ * @returns {Sharp}
+ * @throws {Error} unsupported format or options
+ */
+const toFormat = function toFormat (format, options) {
+  if (is.object(format) && is.string(format.id)) {
+    format = format.id;
+  }
+  if (!is.inArray(format, ['jpeg', 'png', 'webp', 'tiff', 'raw'])) {
+    throw new Error('Unsupported output format ' + format);
+  }
+  return this[format](options);
+};
+
+/**
+ * Use tile-based deep zoom (image pyramid) output.
+ * Set the format and options for tile images via the `toFormat`, `jpeg`, `png` or `webp` functions.
+ * Use a `.zip` or `.szi` file extension with `toFile` to write to a compressed archive file format.
+ *
+ * @example
+ *  sharp('input.tiff')
+ *   .png()
+ *   .tile({
+ *     size: 512
+ *   })
+ *   .toFile('output.dz', function(err, info) {
+ *     // output.dzi is the Deep Zoom XML definition
+ *     // output_files contains 512x512 tiles grouped by zoom level
+ *   });
+ *
+ * @param {Object} [tile]
+ * @param {Number} [tile.size=256] tile size in pixels, a value between 1 and 8192.
+ * @param {Number} [tile.overlap=0] tile overlap in pixels, a value between 0 and 8192.
+ * @param {String} [tile.container='fs'] tile container, with value `fs` (filesystem) or `zip` (compressed file).
+ * @param {String} [tile.layout='dz'] filesystem layout, possible values are `dz`, `zoomify` or `google`.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const tile = function tile (tile) {
+  if (is.object(tile)) {
+    // Size of square tiles, in pixels
+    if (is.defined(tile.size)) {
+      if (is.integer(tile.size) && is.inRange(tile.size, 1, 8192)) {
+        this.options.tileSize = tile.size;
+      } else {
+        throw new Error('Invalid tile size (1 to 8192) ' + tile.size);
+      }
+    }
+    // Overlap of tiles, in pixels
+    if (is.defined(tile.overlap)) {
+      if (is.integer(tile.overlap) && is.inRange(tile.overlap, 0, 8192)) {
+        if (tile.overlap > this.options.tileSize) {
+          throw new Error('Tile overlap ' + tile.overlap + ' cannot be larger than tile size ' + this.options.tileSize);
+        }
+        this.options.tileOverlap = tile.overlap;
+      } else {
+        throw new Error('Invalid tile overlap (0 to 8192) ' + tile.overlap);
+      }
+    }
+    // Container
+    if (is.defined(tile.container)) {
+      if (is.string(tile.container) && is.inArray(tile.container, ['fs', 'zip'])) {
+        this.options.tileContainer = tile.container;
+      } else {
+        throw new Error('Invalid tile container ' + tile.container);
+      }
+    }
+    // Layout
+    if (is.defined(tile.layout)) {
+      if (is.string(tile.layout) && is.inArray(tile.layout, ['dz', 'google', 'zoomify'])) {
+        this.options.tileLayout = tile.layout;
+      } else {
+        throw new Error('Invalid tile layout ' + tile.layout);
+      }
+    }
+  }
+  // Format
+  if (is.inArray(this.options.formatOut, ['jpeg', 'png', 'webp'])) {
+    this.options.tileFormat = this.options.formatOut;
+  } else if (this.options.formatOut !== 'input') {
+    throw new Error('Invalid tile format ' + this.options.formatOut);
+  }
+  return this._updateFormatOut('dz');
+};
+
+/**
+ * Update the output format unless options.force is false,
+ * in which case revert to input format.
+ * @private
+ * @param {String} formatOut
+ * @param {Object} [options]
+ * @param {Boolean} [options.force=true] - force output format, otherwise attempt to use input format
+ * @returns {Sharp}
+ */
+const _updateFormatOut = function _updateFormatOut (formatOut, options) {
+  this.options.formatOut = (is.object(options) && options.force === false) ? 'input' : formatOut;
+  return this;
+};
+
+/**
+ * Update a Boolean attribute of the this.options Object.
+ * @private
+ * @param {String} key
+ * @param {Boolean} val
+ * @throws {Error} Invalid key
+ */
+const _setBooleanOption = function _setBooleanOption (key, val) {
+  if (is.bool(val)) {
+    this.options[key] = val;
+  } else {
+    throw new Error('Invalid ' + key + ' (boolean) ' + val);
+  }
+};
+
+/**
+ * Called by a WriteableStream to notify us it is ready for data.
+ * @private
+ */
+const _read = function _read () {
+  if (!this.options.streamOut) {
+    this.options.streamOut = true;
+    this._pipeline();
+  }
+};
+
+/**
+ * Invoke the C++ image processing pipeline
+ * Supports callback, stream and promise variants
+ * @private
+ */
+const _pipeline = function _pipeline (callback) {
+  const that = this;
+  if (typeof callback === 'function') {
+    // output=file/buffer
+    if (this._isStreamInput()) {
+      // output=file/buffer, input=stream
+      this.on('finish', function () {
+        that._flattenBufferIn();
+        sharp.pipeline(that.options, callback);
+      });
+    } else {
+      // output=file/buffer, input=file/buffer
+      sharp.pipeline(this.options, callback);
+    }
+    return this;
+  } else if (this.options.streamOut) {
+    // output=stream
+    if (this._isStreamInput()) {
+      // output=stream, input=stream
+      if (this.streamInFinished) {
+        this._flattenBufferIn();
+        sharp.pipeline(this.options, function (err, data, info) {
+          if (err) {
+            that.emit('error', err);
+          } else {
+            that.emit('info', info);
+            that.push(data);
+          }
+          that.push(null);
+        });
+      } else {
+        this.on('finish', function () {
+          that._flattenBufferIn();
+          sharp.pipeline(that.options, function (err, data, info) {
+            if (err) {
+              that.emit('error', err);
+            } else {
+              that.emit('info', info);
+              that.push(data);
+            }
+            that.push(null);
+          });
+        });
+      }
+    } else {
+      // output=stream, input=file/buffer
+      sharp.pipeline(this.options, function (err, data, info) {
+        if (err) {
+          that.emit('error', err);
+        } else {
+          that.emit('info', info);
+          that.push(data);
+        }
+        that.push(null);
+      });
+    }
+    return this;
+  } else {
+    // output=promise
+    if (this._isStreamInput()) {
+      // output=promise, input=stream
+      return new Promise(function (resolve, reject) {
+        that.on('finish', function () {
+          that._flattenBufferIn();
+          sharp.pipeline(that.options, function (err, data) {
+            if (err) {
+              reject(err);
+            } else {
+              resolve(data);
+            }
+          });
+        });
+      });
+    } else {
+      // output=promise, input=file/buffer
+      return new Promise(function (resolve, reject) {
+        sharp.pipeline(that.options, function (err, data) {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(data);
+          }
+        });
+      });
+    }
+  }
+};
+
+// Deprecated output options
+/* istanbul ignore next */
+const quality = util.deprecate(function (quality) {
+  const formatOut = this.options.formatOut;
+  const options = { quality: quality };
+  this.jpeg(options).webp(options).tiff(options);
+  this.options.formatOut = formatOut;
+  return this;
+}, 'quality: use jpeg({ quality: ... }), webp({ quality: ... }) and/or tiff({ quality: ... }) instead');
+/* istanbul ignore next */
+const progressive = util.deprecate(function (progressive) {
+  const formatOut = this.options.formatOut;
+  const options = { progressive: (progressive !== false) };
+  this.jpeg(options).png(options);
+  this.options.formatOut = formatOut;
+  return this;
+}, 'progressive: use jpeg({ progressive: ... }) and/or png({ progressive: ... }) instead');
+/* istanbul ignore next */
+const compressionLevel = util.deprecate(function (compressionLevel) {
+  const formatOut = this.options.formatOut;
+  this.png({ compressionLevel: compressionLevel });
+  this.options.formatOut = formatOut;
+  return this;
+}, 'compressionLevel: use png({ compressionLevel: ... }) instead');
+/* istanbul ignore next */
+const withoutAdaptiveFiltering = util.deprecate(function (withoutAdaptiveFiltering) {
+  const formatOut = this.options.formatOut;
+  this.png({ adaptiveFiltering: (withoutAdaptiveFiltering === false) });
+  this.options.formatOut = formatOut;
+  return this;
+}, 'withoutAdaptiveFiltering: use png({ adaptiveFiltering: ... }) instead');
+/* istanbul ignore next */
+const withoutChromaSubsampling = util.deprecate(function (withoutChromaSubsampling) {
+  const formatOut = this.options.formatOut;
+  this.jpeg({ chromaSubsampling: (withoutChromaSubsampling === false) ? '4:2:0' : '4:4:4' });
+  this.options.formatOut = formatOut;
+  return this;
+}, 'withoutChromaSubsampling: use jpeg({ chromaSubsampling: "4:4:4" }) instead');
+/* istanbul ignore next */
+const trellisQuantisation = util.deprecate(function (trellisQuantisation) {
+  const formatOut = this.options.formatOut;
+  this.jpeg({ trellisQuantisation: (trellisQuantisation !== false) });
+  this.options.formatOut = formatOut;
+  return this;
+}, 'trellisQuantisation: use jpeg({ trellisQuantisation: ... }) instead');
+/* istanbul ignore next */
+const overshootDeringing = util.deprecate(function (overshootDeringing) {
+  const formatOut = this.options.formatOut;
+  this.jpeg({ overshootDeringing: (overshootDeringing !== false) });
+  this.options.formatOut = formatOut;
+  return this;
+}, 'overshootDeringing: use jpeg({ overshootDeringing: ... }) instead');
+/* istanbul ignore next */
+const optimiseScans = util.deprecate(function (optimiseScans) {
+  const formatOut = this.options.formatOut;
+  this.jpeg({ optimiseScans: (optimiseScans !== false) });
+  this.options.formatOut = formatOut;
+  return this;
+}, 'optimiseScans: use jpeg({ optimiseScans: ... }) instead');
+
+/**
+ * Decorate the Sharp prototype with output-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  [
+    // Public
+    toFile,
+    toBuffer,
+    withMetadata,
+    jpeg,
+    png,
+    webp,
+    tiff,
+    raw,
+    toFormat,
+    tile,
+    // Private
+    _updateFormatOut,
+    _setBooleanOption,
+    _read,
+    _pipeline
+  ].forEach(function (f) {
+    Sharp.prototype[f.name] = f;
+  });
+  // Deprecated
+  Sharp.prototype.quality = quality;
+  Sharp.prototype.progressive = progressive;
+  Sharp.prototype.compressionLevel = compressionLevel;
+  Sharp.prototype.withoutAdaptiveFiltering = withoutAdaptiveFiltering;
+  Sharp.prototype.withoutChromaSubsampling = withoutChromaSubsampling;
+  Sharp.prototype.trellisQuantisation = trellisQuantisation;
+  Sharp.prototype.trellisQuantization = trellisQuantisation;
+  Sharp.prototype.overshootDeringing = overshootDeringing;
+  Sharp.prototype.optimiseScans = optimiseScans;
+  Sharp.prototype.optimizeScans = optimiseScans;
+};

lib/resize.js

@@ -0,0 +1,301 @@
+'use strict';
+
+const is = require('./is');
+
+/**
+ * Weighting to apply to image crop.
+ * @member
+ * @private
+ */
+const gravity = {
+  center: 0,
+  centre: 0,
+  north: 1,
+  east: 2,
+  south: 3,
+  west: 4,
+  northeast: 5,
+  southeast: 6,
+  southwest: 7,
+  northwest: 8
+};
+
+/**
+ * Strategies for automagic crop behaviour.
+ * @member
+ * @private
+ */
+const strategy = {
+  entropy: 16,
+  attention: 17
+};
+
+/**
+ * Reduction kernels.
+ * @member
+ * @private
+ */
+const kernel = {
+  cubic: 'cubic',
+  lanczos2: 'lanczos2',
+  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:
+ * - `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
+ *   })
+ *   .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,
+ *     // of the image data in inputBuffer
+ *   });
+ *
+ * @param {Number} [width] - pixels wide the resultant image should be, between 1 and 16383 (0x3FFF). Use `null` or `undefined` to auto-scale the width to match the height.
+ * @param {Number} [height] - pixels high the resultant image should be, between 1 and 16383. 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.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const resize = function resize (width, height, options) {
+  if (is.defined(width)) {
+    if (is.integer(width) && is.inRange(width, 1, this.constructor.maximum.width)) {
+      this.options.width = width;
+    } else {
+      throw is.invalidParameterError('width', `integer between 1 and ${this.constructor.maximum.width}`, width);
+    }
+  } else {
+    this.options.width = -1;
+  }
+  if (is.defined(height)) {
+    if (is.integer(height) && is.inRange(height, 1, this.constructor.maximum.height)) {
+      this.options.height = height;
+    } else {
+      throw is.invalidParameterError('height', `integer between 1 and ${this.constructor.maximum.height}`, height);
+    }
+  } else {
+    this.options.height = -1;
+  }
+  if (is.object(options)) {
+    // Kernel
+    if (is.defined(options.kernel)) {
+      if (is.string(kernel[options.kernel])) {
+        this.options.kernel = kernel[options.kernel];
+      } else {
+        throw is.invalidParameterError('kernel', 'valid kernel name', options.kernel);
+      }
+    }
+    // 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);
+    }
+  }
+  return this;
+};
+
+/**
+ * Crop the resized image to the exact size specified, the default behaviour.
+ *
+ * Possible attributes of the optional `sharp.gravity` are `north`, `northeast`, `east`, `southeast`, `south`,
+ * `southwest`, `west`, `northwest`, `center` and `centre`.
+ *
+ * The experimental strategy-based approach resizes so one dimension is at its target length
+ * then repeatedly ranks edge regions, discarding the edge with the lowest score based on the selected strategy.
+ * - `entropy`: focus on the region with the highest [Shannon entropy](https://en.wikipedia.org/wiki/Entropy_%28information_theory%29).
+ * - `attention`: focus on the region with the highest luminance frequency, colour saturation and presence of skin tones.
+ *
+ * @example
+ * const transformer = sharp()
+ *   .resize(200, 200)
+ *   .crop(sharp.strategy.entropy)
+ *   .on('error', function(err) {
+ *     console.log(err);
+ *   });
+ * // Read image data from readableStream
+ * // Write 200px square auto-cropped image data to writableStream
+ * readableStream.pipe(transformer).pipe(writableStream);
+ *
+ * @param {String} [crop='centre'] - A member of `sharp.gravity` to crop to an edge/corner or `sharp.strategy` to crop dynamically.
+ * @returns {Sharp}
+ * @throws {Error} Invalid parameters
+ */
+const crop = function crop (crop) {
+  this.options.canvas = 'crop';
+  if (!is.defined(crop)) {
+    // Default
+    this.options.crop = gravity.center;
+  } else if (is.integer(crop) && is.inRange(crop, 0, 8)) {
+    // Gravity (numeric)
+    this.options.crop = crop;
+  } else if (is.string(crop) && is.integer(gravity[crop])) {
+    // Gravity (string)
+    this.options.crop = gravity[crop];
+  } else if (is.integer(crop) && crop >= strategy.entropy) {
+    // Strategy
+    this.options.crop = crop;
+  } else {
+    throw is.invalidParameterError('crop', 'valid crop id/name/strategy', crop);
+  }
+  return this;
+};
+
+/**
+ * Preserving aspect ratio, resize the image to the maximum `width` or `height` specified
+ * then embed on a background of the exact `width` and `height` specified.
+ *
+ * If the background contains an alpha value then WebP and PNG format output images will
+ * contain an alpha channel, even when the input image does not.
+ *
+ * @example
+ * sharp('input.gif')
+ *   .resize(200, 300)
+ *   .background({r: 0, g: 0, b: 0, alpha: 0})
+ *   .embed()
+ *   .toFormat(sharp.format.webp)
+ *   .toBuffer(function(err, outputBuffer) {
+ *     if (err) {
+ *       throw err;
+ *     }
+ *     // outputBuffer contains WebP image data of a 200 pixels wide and 300 pixels high
+ *     // containing a scaled version, embedded on a transparent canvas, of input.gif
+ *   });
+ *
+ * @returns {Sharp}
+ */
+const embed = function embed () {
+  this.options.canvas = 'embed';
+  return this;
+};
+
+/**
+ * Preserving aspect ratio, resize the image to be as large as possible
+ * while ensuring its dimensions are less than or equal to the `width` and `height` specified.
+ *
+ * Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
+ *
+ * @example
+ * sharp(inputBuffer)
+ *   .resize(200, 200)
+ *   .max()
+ *   .toFormat('jpeg')
+ *   .toBuffer()
+ *   .then(function(outputBuffer) {
+ *     // outputBuffer contains JPEG image data no wider than 200 pixels and no higher
+ *     // than 200 pixels regardless of the inputBuffer image dimensions
+ *   });
+ *
+ * @returns {Sharp}
+ */
+const max = function max () {
+  this.options.canvas = 'max';
+  return this;
+};
+
+/**
+ * Preserving aspect ratio, resize the image to be as small as possible
+ * while ensuring its dimensions are greater than or equal to the `width` and `height` specified.
+ *
+ * Both `width` and `height` must be provided via `resize` otherwise the behaviour will default to `crop`.
+ *
+ * @returns {Sharp}
+ */
+const min = function min () {
+  this.options.canvas = 'min';
+  return this;
+};
+
+/**
+ * Ignoring the aspect ratio of the input, stretch the image to
+ * the exact `width` and/or `height` provided via `resize`.
+ * @returns {Sharp}
+ */
+const ignoreAspectRatio = function ignoreAspectRatio () {
+  this.options.canvas = 'ignore_aspect';
+  return this;
+};
+
+/**
+ * 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*".
+ * @param {Boolean} [withoutEnlargement=true]
+ * @returns {Sharp}
+*/
+const withoutEnlargement = function withoutEnlargement (withoutEnlargement) {
+  this.options.withoutEnlargement = is.bool(withoutEnlargement) ? withoutEnlargement : true;
+  return this;
+};
+
+/**
+ * Decorate the Sharp prototype with resize-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  [
+    resize,
+    crop,
+    embed,
+    max,
+    min,
+    ignoreAspectRatio,
+    withoutEnlargement
+  ].forEach(function (f) {
+    Sharp.prototype[f.name] = f;
+  });
+  // Class attributes
+  Sharp.gravity = gravity;
+  Sharp.strategy = strategy;
+  Sharp.kernel = kernel;
+  Sharp.interpolator = interpolator;
+};

lib/utility.js

@@ -0,0 +1,116 @@
+'use strict';
+
+const is = require('./is');
+const sharp = require('../build/Release/sharp.node');
+
+/**
+ * Gets, or when options are provided sets, the limits of _libvips'_ operation cache.
+ * Existing entries in the cache will be trimmed after any change in limits.
+ * This method always returns cache statistics,
+ * useful for determining how much working memory is required for a particular task.
+ *
+ * @example
+ * const stats = sharp.cache();
+ * @example
+ * sharp.cache( { items: 200 } );
+ * sharp.cache( { files: 0 } );
+ * sharp.cache(false);
+ *
+ * @param {Object|Boolean} options - Object with the following attributes, or Boolean where true uses default cache settings and false removes all caching.
+ * @param {Number} [options.memory=50] - is the maximum memory in MB to use for this cache
+ * @param {Number} [options.files=20] - is the maximum number of files to hold open
+ * @param {Number} [options.items=100] - is the maximum number of operations to cache
+ * @returns {Object}
+ */
+const cache = function cache (options) {
+  if (is.bool(options)) {
+    if (options) {
+      // Default cache settings of 50MB, 20 files, 100 items
+      return sharp.cache(50, 20, 100);
+    } else {
+      return sharp.cache(0, 0, 0);
+    }
+  } else if (is.object(options)) {
+    return sharp.cache(options.memory, options.files, options.items);
+  } else {
+    return sharp.cache();
+  }
+};
+cache(true);
+
+/**
+ * Gets, or when a concurrency is provided sets,
+ * the number of threads _libvips'_ should create to process each image.
+ * The default value is the number of CPU cores.
+ * A value of `0` will reset to this default.
+ *
+ * The maximum number of images that can be processed in parallel
+ * is limited by libuv's `UV_THREADPOOL_SIZE` environment variable.
+ *
+ * This method always returns the current concurrency.
+ *
+ * @example
+ * const threads = sharp.concurrency(); // 4
+ * sharp.concurrency(2); // 2
+ * sharp.concurrency(0); // 4
+ *
+ * @param {Number} [concurrency]
+ * @returns {Number} concurrency
+ */
+const concurrency = function concurrency (concurrency) {
+  return sharp.concurrency(is.integer(concurrency) ? concurrency : null);
+};
+
+/**
+ * Provides access to internal task counters.
+ * - queue is the number of tasks this module has queued waiting for _libuv_ to provide a worker thread from its pool.
+ * - process is the number of resize tasks currently being processed.
+ *
+ * @example
+ * const counters = sharp.counters(); // { queue: 2, process: 4 }
+ *
+ * @returns {Object}
+ */
+const counters = function counters () {
+  return sharp.counters();
+};
+
+/**
+ * Get and set use of SIMD vector unit instructions.
+ * Requires libvips to have been compiled with liborc support.
+ *
+ * Improves the performance of `resize`, `blur` and `sharpen` operations
+ * by taking advantage of the SIMD vector unit of the CPU, e.g. Intel SSE and ARM NEON.
+ *
+ * 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.
+ *
+ * @example
+ * const simd = sharp.simd();
+ * // simd is `true` if SIMD is currently enabled
+ * @example
+ * const simd = sharp.simd(true);
+ * // attempts to enable the use of SIMD, returning true if available
+ *
+ * @param {Boolean} [simd=false]
+ * @returns {Boolean}
+ */
+const simd = function simd (simd) {
+  return sharp.simd(is.bool(simd) ? simd : null);
+};
+simd(false);
+
+/**
+ * Decorate the Sharp class with utility-related functions.
+ * @private
+ */
+module.exports = function (Sharp) {
+  [
+    cache,
+    concurrency,
+    counters,
+    simd
+  ].forEach(function (f) {
+    Sharp[f.name] = f;
+  });
+};

mkdocs.yml

@@ -12,6 +12,15 @@ dev_addr: 0.0.0.0:10101
 pages:
   - Home: index.md
   - Installation: install.md
-  - API: api.md
+  - API:
+    - Constructor: api-constructor.md
+    - Input: api-input.md
+    - Output: api-output.md
+    - "Resizing images": api-resize.md
+    - "Compositing images": api-composite.md
+    - "Image operations": api-operation.md
+    - "Colour manipulation": api-colour.md
+    - "Channel manipulation": api-channel.md
+    - Utilities: api-utility.md
   - Performance: performance.md
   - Changelog: changelog.md

package.json

@@ -1,7 +1,9 @@
 {
   "name": "sharp",
-  "version": "0.16.2",
+  "description": "High performance Node.js image processing, the fastest module to resize JPEG, PNG, WebP and TIFF images",
+  "version": "0.17.2",
   "author": "Lovell Fuller <npm@lovell.info>",
+  "homepage": "https://github.com/lovell/sharp",
   "contributors": [
     "Pierre Inglebert <pierre.inglebert@gmail.com>",
     "Jonathan Ong <jonathanrichardong@gmail.com>",
@@ -27,18 +29,19 @@
     "F. Orlando Galashan <frulo@gmx.de>",
     "Kleis Auke Wolthuizen <info@kleisauke.nl>",
     "Matt Hirsch <mhirsch@media.mit.edu>",
-    "Matthias Thoemmes <thoemmes@gmail.com>"
+    "Matthias Thoemmes <thoemmes@gmail.com>",
+    "Patrick Paskaris <patrick@paskaris.gr>",
+    "Jérémy Lal <kapouer@melix.org>",
+    "Rahul Nanwani <r.nanwani@gmail.com>"
   ],
-  "description": "High performance Node.js image processing, the fastest module to resize JPEG, PNG, WebP and TIFF images",
   "scripts": {
-    "clean": "rm -rf node_modules/ build/ include/ lib/ coverage/ test/fixtures/output.*",
-    "test": "VIPS_WARNING=0 node ./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha -- --slow=5000 --timeout=30000 ./test/unit/*.js",
-    "test-win": "node ./node_modules/mocha/bin/mocha --slow=5000 --timeout=60000 ./test/unit/*.js",
+    "clean": "rm -rf node_modules/ build/ vendor/ coverage/ test/fixtures/output.*",
+    "test": "semistandard && cc && cross-env VIPS_WARNING=0 nyc --reporter=lcov --branches=99 mocha --slow=5000 --timeout=60000 ./test/unit/*.js",
     "test-leak": "./test/leak/leak.sh",
     "test-packaging": "./packaging/test-linux-x64.sh",
-    "test-clean": "rm -rf coverage/ test/fixtures/output.* && npm install && npm test"
+    "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"
   },
-  "main": "index.js",
+  "main": "lib/index.js",
   "repository": {
     "type": "git",
     "url": "git://github.com/lovell/sharp"
@@ -59,31 +62,44 @@
     "vips"
   ],
   "dependencies": {
-    "bluebird": "^3.4.6",
-    "color": "^0.11.3",
-    "nan": "^2.4.0",
+    "caw": "^2.0.0",
+    "color": "^1.0.3",
+    "got": "^6.7.1",
+    "nan": "^2.5.1",
     "semver": "^5.3.0",
-    "request": "^2.75.0",
     "tar": "^2.2.1"
   },
   "devDependencies": {
-    "async": "^2.1.2",
-    "bufferutil": "^1.2.1",
-    "coveralls": "^2.11.14",
-    "exif-reader": "^1.0.1",
-    "icc": "^0.0.2",
-    "istanbul": "^0.4.5",
-    "mocha": "^3.1.2",
-    "mocha-jshint": "^2.3.1",
-    "node-cpplint": "^0.4.0",
+    "async": "^2.1.4",
+    "bufferutil": "^2.0.1",
+    "cc": "^1.0.0",
+    "cross-env": "^3.1.4",
+    "documentation": "^4.0.0-beta.18",
+    "exif-reader": "^1.0.2",
+    "icc": "^1.0.0",
+    "mocha": "^3.2.0",
+    "nyc": "^10.1.2",
     "rimraf": "^2.5.4",
+    "semistandard": "^9.2.1",
     "unzip": "^0.1.11"
   },
   "license": "Apache-2.0",
   "config": {
-    "libvips": "8.3.3"
+    "libvips": "8.4.2"
   },
   "engines": {
-    "node": ">=0.10"
+    "node": ">=4"
+  },
+  "semistandard": {
+    "env": [
+      "mocha"
+    ]
+  },
+  "cc": {
+    "linelength": "120",
+    "filter": [
+      "build/include",
+      "runtime/indentation_namespace"
+    ]
   }
 }

packaging/build/lin.sh

@@ -16,25 +16,25 @@ export CFLAGS="${FLAGS}"
 export CXXFLAGS="${FLAGS}"
 
 # Dependency version numbers
-VERSION_ZLIB=1.2.8
+VERSION_ZLIB=1.2.10
 VERSION_FFI=3.2.1
-VERSION_GLIB=2.49.4
+VERSION_GLIB=2.50.1
 VERSION_XML2=2.9.4
-VERSION_GSF=1.14.39
+VERSION_GSF=1.14.40
 VERSION_EXIF=0.6.21
 VERSION_LCMS2=2.8
-VERSION_JPEG=1.5.0
-VERSION_PNG16=1.6.25
+VERSION_JPEG=1.5.1
+VERSION_PNG16=1.6.28
 VERSION_WEBP=0.5.1
 VERSION_TIFF=4.0.6
-VERSION_ORC=0.4.25
-VERSION_GDKPIXBUF=2.35.2
-VERSION_FREETYPE=2.6.5
-VERSION_FONTCONFIG=2.12.0
-VERSION_HARFBUZZ=1.3.0
+VERSION_ORC=0.4.26
+VERSION_GDKPIXBUF=2.36.0
+VERSION_FREETYPE=2.7
+VERSION_FONTCONFIG=2.12.1
+VERSION_HARFBUZZ=1.3.2
 VERSION_PIXMAN=0.34.0
 VERSION_CAIRO=1.14.6
-VERSION_PANGO=1.40.1
+VERSION_PANGO=1.40.3
 VERSION_CROCO=0.6.11
 VERSION_SVG=2.40.16
 VERSION_GIF=5.1.4
@@ -56,11 +56,11 @@ cd ${DEPS}/ffi
 make install-strip
 
 mkdir ${DEPS}/glib
-curl -Ls https://download.gnome.org/sources/glib/2.49/glib-${VERSION_GLIB}.tar.xz | tar xJC ${DEPS}/glib --strip-components=1
+curl -Ls https://download.gnome.org/sources/glib/2.50/glib-${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=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --with-pcre=internal
+./configure --cache-file=glib.cache --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --with-pcre=internal --disable-libmount
 make install-strip
 
 mkdir ${DEPS}/xml2
@@ -112,8 +112,11 @@ 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 ${DEPS}/tiff
+# Apply patches for various libtiff security vulnerabilities reported since v4.0.6
+VERSION_TIFF_GIT_MASTER_SHA=$(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-v4-0-6...master.patch | patch -p1 -t || true
 if [ -n "${CHOST}" ]; then autoreconf -fiv; fi
-./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-mdi --disable-cxx
+./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-mdi --disable-pixarlog --disable-cxx
 make install-strip
 
 mkdir ${DEPS}/orc
@@ -125,10 +128,10 @@ cd ${TARGET}/lib
 rm -rf liborc-test-*
 
 mkdir ${DEPS}/gdkpixbuf
-curl -Ls https://download.gnome.org/sources/gdk-pixbuf/2.35/gdk-pixbuf-${VERSION_GDKPIXBUF}.tar.xz | tar xJC ${DEPS}/gdkpixbuf --strip-components=1
+curl -Ls https://download.gnome.org/sources/gdk-pixbuf/2.36/gdk-pixbuf-${VERSION_GDKPIXBUF}.tar.xz | tar xJC ${DEPS}/gdkpixbuf --strip-components=1
 cd ${DEPS}/gdkpixbuf
 LD_LIBRARY_PATH=${TARGET}/lib \
-./configure --cache-file=gdkpixbuf.cache --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --disable-introspection --disable-modules --disable-gio-sniffing --without-libpng --without-libjpeg --without-libtiff --without-gdiplus --with-included-loaders=
+./configure --cache-file=gdkpixbuf.cache --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
@@ -140,7 +143,7 @@ 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=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --enable-libxml2
+./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking --enable-libxml2 --sysconfdir=/etc
 make install-strip
 
 mkdir ${DEPS}/harfbuzz
@@ -188,7 +191,7 @@ cd ${DEPS}/gif
 make install-strip
 
 mkdir ${DEPS}/vips
-curl -Ls http://www.vips.ecs.soton.ac.uk/supported/8.3/vips-${VERSION_VIPS}.tar.gz | tar xzC ${DEPS}/vips --strip-components=1
+curl -Ls http://www.vips.ecs.soton.ac.uk/supported/8.4/vips-${VERSION_VIPS}.tar.gz | tar xzC ${DEPS}/vips --strip-components=1
 cd ${DEPS}/vips
 ./configure --host=${CHOST} --prefix=${TARGET} --enable-shared --disable-static --disable-dependency-tracking \
   --disable-debug --disable-introspection --without-python --without-fftw \
@@ -224,7 +227,7 @@ echo "{\n\
   \"pixman\": \"${VERSION_PIXMAN}\",\n\
   \"png\": \"${VERSION_PNG16}\",\n\
   \"svg\": \"${VERSION_SVG}\",\n\
-  \"tiff\": \"${VERSION_TIFF}\",\n\
+  \"tiff\": \"${VERSION_TIFF}-${VERSION_TIFF_GIT_MASTER_SHA}\",\n\
   \"vips\": \"${VERSION_VIPS}\",\n\
   \"webp\": \"${VERSION_WEBP}\",\n\
   \"xml\": \"${VERSION_XML2}\",\n\

packaging/build/win.sh

@@ -8,11 +8,14 @@ curl -L -O https://github.com/lovell/build-win64/releases/download/v${VERSION_VI
 unzip vips-dev-w64-web-${VERSION_VIPS}.zip
 
 # Clean and zip
-cd /vips/vips-dev-8.3
+cd /vips/vips-dev-8.4
 rm bin/libvipsCC-42.dll bin/libvips-cpp-42.dll bin/libgsf-win32-1-114.dll
 cp bin/*.dll lib/
 cp -r lib64/* lib/
 
+# Temp patch for __declspec ordering
+curl -L -o include/vips/VImage8.h https://raw.githubusercontent.com/lovell/libvips/e1aef0445bf123d2de000bc7f2ef97b9f788eea0/cplusplus/include/vips/VImage8.h
+
 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"

packaging/linux-armv6/Dockerfile

@@ -7,7 +7,7 @@ MAINTAINER Lovell Fuller <npm@lovell.info>
 # Build dependencies
 RUN \
   apt-get update && \
-  apt-get install -y build-essential curl autoconf libtool nasm gtk-doc-tools texinfo advancecomp libglib2.0-dev
+  apt-get install -y build-essential curl autoconf libtool nasm gtk-doc-tools texinfo advancecomp libglib2.0-dev jq
 
 # Compiler settings
 ENV \

packaging/linux-armv7/Dockerfile

@@ -11,7 +11,7 @@ RUN \
   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
+  apt-get install -y crossbuild-essential-armhf autoconf libtool nasm gtk-doc-tools texinfo advancecomp libglib2.0-dev jq
 
 # Compiler settings
 ENV \

packaging/linux-armv8/Dockerfile

@@ -9,10 +9,10 @@ RUN \
   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
+  apt-get install -y crossbuild-essential-arm64 autoconf libtool nasm gtk-doc-tools texinfo advancecomp libglib2.0-dev jq
 
 # Compiler settings
 ENV \
   PLATFORM=linux-armv8 \
   CHOST=aarch64-linux-gnu \
-  FLAGS="-march=armv8-a -Os -D_GLIBCXX_USE_CXX11_ABI=0"
+  FLAGS="-march=armv8-a -Os"

packaging/linux-x64/Dockerfile

@@ -5,8 +5,10 @@ MAINTAINER Lovell Fuller <npm@lovell.info>
 
 # 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 install -y build-essential autoconf libtool nasm gtk-doc-tools texinfo advancecomp && \
+  apt-get -t wheezy-backports install -y jq
 
 # Compiler settings
 ENV \

preinstall.sh

@@ -1,316 +0,0 @@
-#!/bin/sh
-
-# Use of this script is deprecated
-
-echo
-echo "WARNING: This script will stop working at the end of 2016"
-echo
-echo "WARNING: This script is no longer required on most 64-bit Linux systems when using sharp v0.12.0+"
-echo
-echo "See http://sharp.dimens.io/page/install#linux"
-echo
-echo "If you really, really need this script, it will attempt"
-echo "to globally install libvips if not already available."
-echo
-sleep 5
-
-vips_version_minimum=8.3.3
-vips_version_latest_major_minor=8.3
-vips_version_latest_patch=3
-
-openslide_version_minimum=3.4.0
-openslide_version_latest_major_minor=3.4
-openslide_version_latest_patch=1
-
-install_libvips_from_source() {
-  echo "Compiling libvips $vips_version_latest_major_minor.$vips_version_latest_patch from source"
-  curl -O http://www.vips.ecs.soton.ac.uk/supported/$vips_version_latest_major_minor/vips-$vips_version_latest_major_minor.$vips_version_latest_patch.tar.gz
-  tar zvxf vips-$vips_version_latest_major_minor.$vips_version_latest_patch.tar.gz
-  cd vips-$vips_version_latest_major_minor.$vips_version_latest_patch
-  CXXFLAGS="-D_GLIBCXX_USE_CXX11_ABI=0" ./configure --disable-debug --disable-docs --disable-static --disable-introspection --disable-dependency-tracking --enable-cxx=yes --without-python --without-orc --without-fftw $1
-  make
-  make install
-  cd ..
-  rm -rf vips-$vips_version_latest_major_minor.$vips_version_latest_patch
-  rm vips-$vips_version_latest_major_minor.$vips_version_latest_patch.tar.gz
-  ldconfig
-  echo "Installed libvips $(PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig:/usr/lib/pkgconfig pkg-config --modversion vips)"
-}
-
-install_libopenslide_from_source() {
-  echo "Compiling openslide $openslide_version_latest_major_minor.$openslide_version_latest_patch from source"
-  curl -O -L https://github.com/openslide/openslide/releases/download/v$openslide_version_latest_major_minor.$openslide_version_latest_patch/openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch.tar.gz
-  tar xzvf openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch.tar.gz
-  cd openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch
-  PKG_CONFIG_PATH=$pkg_config_path ./configure $1
-  make
-  make install
-  cd ..
-  rm -rf openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch
-  rm openslide-$openslide_version_latest_major_minor.$openslide_version_latest_patch.tar.gz
-  ldconfig
-  echo "Installed libopenslide $openslide_version_latest_major_minor.$openslide_version_latest_patch"
-}
-
-sorry() {
-  echo "Sorry, I don't yet know how to install lib$1 on $2"
-  exit 1
-}
-
-pkg_config_path="$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig:/usr/lib/pkgconfig"
-
-check_if_library_exists() {
-  PKG_CONFIG_PATH=$pkg_config_path pkg-config --exists $1
-  if [ $? -eq 0 ]; then
-    version_found=$(PKG_CONFIG_PATH=$pkg_config_path pkg-config --modversion $1)
-    PKG_CONFIG_PATH=$pkg_config_path pkg-config --atleast-version=$2 $1
-    if [ $? -eq 0 ]; then
-      # Found suitable version of libvips
-      echo "Found lib$1 $version_found"
-      return 1
-    fi
-    echo "Found lib$1 $version_found but require $2"
-  else
-    echo "Could not find lib$1 using a PKG_CONFIG_PATH of '$pkg_config_path'"
-  fi
-  return 0
-}
-
-enable_openslide=0
-# Is libvips already installed, and is it at least the minimum required version?
-if [ $# -eq 1 ]; then
-  if [ "$1" = "--with-openslide" ]; then
-    echo "Installing vips with openslide support"
-    enable_openslide=1
-  else
-    echo "Sorry, $1 is not supported. Did you mean --with-openslide?"
-    exit 1
-  fi
-fi
-
-if ! type pkg-config >/dev/null; then
-  sorry "vips" "a system without pkg-config"
-fi
-
-openslide_exists=0
-if [ $enable_openslide -eq 1 ]; then
-  check_if_library_exists "openslide" "$openslide_version_minimum"
-  openslide_exists=$?
-fi
-
-check_if_library_exists "vips" "$vips_version_minimum"
-vips_exists=$?
-if [ $vips_exists -eq 1 ] && [ $enable_openslide -eq 1 ]; then
-  if [ $openslide_exists -eq 1 ]; then
-    # Check if vips compiled with openslide support
-    vips_with_openslide=`vips list classes | grep -i opensli`
-    if [ -z $vips_with_openslide ]; then
-      echo "Vips compiled without openslide support."
-    else
-      exit 0
-    fi
-  fi
-elif [ $vips_exists -eq 1 ] && [ $enable_openslide -eq 0 ]; then
-  exit 0
-fi
-
-# Verify root/sudo access
-if [ "$(id -u)" -ne "0" ]; then
-  echo "Sorry, I need root/sudo access to continue"
-  exit 1
-fi
-
-# Deprecation warning
-if [ "$(arch)" == "x86_64" ]; then
-  echo "This script is no longer required on most 64-bit Linux systems when using sharp v0.12.0+"
-fi
-
-# OS-specific installations of libopenslide follows
-# Either openslide does not exist, or vips is installed without openslide support
-if [ $enable_openslide -eq 1 ] && [ -z $vips_with_openslide ] && [ $openslide_exists -eq 0 ]; then
-  if [ -f /etc/debian_version ]; then
-    # Debian Linux
-    DISTRO=$(lsb_release -c -s)
-    echo "Detected Debian Linux '$DISTRO'"
-    case "$DISTRO" in
-      jessie|vivid|wily|xenial)
-        # Debian 8, Ubuntu 15
-        echo "Installing libopenslide via apt-get"
-        apt-get install -y libopenslide-dev
-        ;;
-      trusty|utopic|qiana|rebecca|rafaela|freya)
-        # Ubuntu 14, Mint 17
-        echo "Installing libopenslide dependencies via apt-get"
-        apt-get install -y automake build-essential curl zlib1g-dev libopenjpeg-dev libpng12-dev libjpeg-dev libtiff5-dev libgdk-pixbuf2.0-dev libxml2-dev libsqlite3-dev libcairo2-dev libglib2.0-dev sqlite3 libsqlite3-dev
-        install_libopenslide_from_source
-        ;;
-      precise|wheezy|maya)
-        # Debian 7, Ubuntu 12.04, Mint 13
-        echo "Installing libopenslide dependencies via apt-get"
-        apt-get install -y automake build-essential curl zlib1g-dev libopenjpeg-dev libpng12-dev libjpeg-dev libtiff5-dev libgdk-pixbuf2.0-dev libxml2-dev libsqlite3-dev libcairo2-dev libglib2.0-dev sqlite3 libsqlite3-dev
-        install_libopenslide_from_source
-        ;;
-      *)
-        # Unsupported Debian-based OS
-        sorry "openslide" "Debian-based $DISTRO"
-        ;;
-    esac
-  elif [ -f /etc/redhat-release ]; then
-    # Red Hat Linux
-    RELEASE=$(cat /etc/redhat-release)
-    echo "Detected Red Hat Linux '$RELEASE'"
-    case $RELEASE in
-      "Red Hat Enterprise Linux release 7."*|"CentOS Linux release 7."*|"Scientific Linux release 7."*)
-        # RHEL/CentOS 7
-        echo "Installing libopenslide dependencies via yum"
-        yum groupinstall -y "Development Tools"
-        yum install -y tar curl libpng-devel libjpeg-devel libxml2-devel zlib-devel openjpeg-devel libtiff-devel gdk-pixbuf2-devel sqlite-devel cairo-devel glib2-devel
-        install_libopenslide_from_source "--prefix=/usr"
-        ;;
-      "Red Hat Enterprise Linux release 6."*|"CentOS release 6."*|"Scientific Linux release 6."*)
-        # RHEL/CentOS 6
-        echo "Installing libopenslide dependencies via yum"
-        yum groupinstall -y "Development Tools"
-        yum install -y tar curl libpng-devel libjpeg-devel libxml2-devel zlib-devel openjpeg-devel libtiff-devel gdk-pixbuf2-devel sqlite-devel cairo-devel glib2-devel
-        install_libopenslide_from_source "--prefix=/usr"
-        ;;
-      "Fedora release 21 "*|"Fedora release 22 "*)
-        # Fedora 21, 22
-        echo "Installing libopenslide via yum"
-        yum install -y openslide-devel
-        ;;
-      *)
-        # Unsupported RHEL-based OS
-        sorry "openslide" "$RELEASE"
-        ;;
-    esac
-  elif [ -f /etc/os-release ]; then
-    RELEASE=$(cat /etc/os-release | grep VERSION)
-    echo "Detected OpenSuse Linux '$RELEASE'"
-    case $RELEASE in
-      *"13.2"*)
-      echo "Installing libopenslide via zypper"
-      zypper --gpg-auto-import-keys install -y libopenslide-devel
-      ;;
-    esac
-  elif [ -f /etc/SuSE-brand ]; then
-    RELEASE=$(cat /etc/SuSE-brand | grep VERSION)
-    echo "Detected OpenSuse Linux '$RELEASE'"
-    case $RELEASE in
-      *"13.1")
-      echo "Installing libopenslide dependencies via zypper"
-      zypper --gpg-auto-import-keys install -y --type pattern devel_basis
-      zypper --gpg-auto-import-keys install -y tar curl libpng16-devel libjpeg-turbo libjpeg8-devel libxml2-devel zlib-devel openjpeg-devel libtiff-devel libgdk_pixbuf-2_0-0 sqlite3-devel cairo-devel glib2-devel
-      install_libopenslide_from_source
-      ;;
-    esac
-  else
-    # Unsupported OS
-    sorry "openslide" "$(uname -a)"
-  fi
-fi
-
-# OS-specific installations of libvips follows
-
-if [ -f /etc/debian_version ]; then
-  # Debian Linux
-  DISTRO=$(lsb_release -c -s)
-  echo "Detected Debian Linux '$DISTRO'"
-  case "$DISTRO" in
-    jessie|trusty|utopic|vivid|wily|xenial|qiana|rebecca|rafaela|freya)
-      # Debian 8, Ubuntu 14.04+, Mint 17
-      echo "Installing libvips dependencies via apt-get"
-      apt-get install -y automake build-essential gobject-introspection gtk-doc-tools libglib2.0-dev libjpeg-dev libpng12-dev libwebp-dev libtiff5-dev libexif-dev libgsf-1-dev liblcms2-dev libxml2-dev swig libmagickcore-dev curl
-      install_libvips_from_source
-      ;;
-    precise|wheezy|maya)
-      # Debian 7, Ubuntu 12.04, Mint 13
-      echo "Installing libvips dependencies via apt-get"
-      add-apt-repository -y ppa:lyrasis/precise-backports
-      apt-get update
-      apt-get install -y automake build-essential gobject-introspection gtk-doc-tools libglib2.0-dev libjpeg-dev libpng12-dev libwebp-dev libtiff4-dev libexif-dev libgsf-1-dev liblcms2-dev libxml2-dev swig libmagickcore-dev curl
-      install_libvips_from_source
-      ;;
-    *)
-      # Unsupported Debian-based OS
-      sorry "vips" "Debian-based $DISTRO"
-      ;;
-  esac
-elif [ -f /etc/redhat-release ]; then
-  # Red Hat Linux
-  RELEASE=$(cat /etc/redhat-release)
-  echo "Detected Red Hat Linux '$RELEASE'"
-  case $RELEASE in
-    "Red Hat Enterprise Linux release 7."*|"CentOS Linux release 7."*|"Scientific Linux release 7."*)
-      # RHEL/CentOS 7
-      echo "Installing libvips dependencies via yum"
-      yum groupinstall -y "Development Tools"
-      yum install -y tar curl gtk-doc libxml2-devel libjpeg-turbo-devel libpng-devel libtiff-devel libexif-devel libgsf-devel lcms2-devel ImageMagick-devel gobject-introspection-devel libwebp-devel
-      install_libvips_from_source "--prefix=/usr"
-      ;;
-    "Red Hat Enterprise Linux release 6."*|"CentOS release 6."*|"Scientific Linux release 6."*)
-      # RHEL/CentOS 6
-      echo "Installing libvips dependencies via yum"
-      yum groupinstall -y "Development Tools"
-      yum install -y tar curl gtk-doc libxml2-devel libjpeg-turbo-devel libpng-devel libtiff-devel libexif-devel libgsf-devel lcms-devel ImageMagick-devel
-      yum install -y http://li.nux.ro/download/nux/dextop/el6/x86_64/nux-dextop-release-0-2.el6.nux.noarch.rpm
-      yum install -y --enablerepo=nux-dextop gobject-introspection-devel
-      yum install -y http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
-      yum install -y --enablerepo=remi libwebp-devel
-      install_libvips_from_source "--prefix=/usr"
-      ;;
-    "Fedora"*)
-      # Fedora 21, 22, 23
-      echo "Installing libvips dependencies via yum"
-      yum groupinstall -y "Development Tools"
-      yum install -y gcc-c++ gtk-doc libxml2-devel libjpeg-turbo-devel libpng-devel libtiff-devel libexif-devel lcms-devel ImageMagick-devel gobject-introspection-devel libwebp-devel curl
-      install_libvips_from_source "--prefix=/usr"
-      ;;
-    *)
-      # Unsupported RHEL-based OS
-      sorry "vips" "$RELEASE"
-      ;;
-  esac
-elif [ -f /etc/system-release ]; then
-  # Probably Amazon Linux
-  RELEASE=$(cat /etc/system-release)
-  case $RELEASE in
-    "Amazon Linux AMI release 2015.03"|"Amazon Linux AMI release 2015.09")
-      # Amazon Linux
-      echo "Detected '$RELEASE'"
-      echo "Installing libvips dependencies via yum"
-      yum groupinstall -y "Development Tools"
-      yum install -y gtk-doc libxml2-devel libjpeg-turbo-devel libpng-devel libtiff-devel libexif-devel libgsf-devel lcms2-devel ImageMagick-devel gobject-introspection-devel libwebp-devel curl
-      install_libvips_from_source "--prefix=/usr"
-      ;;
-    *)
-      # Unsupported Amazon Linux version
-      sorry "vips" "$RELEASE"
-      ;;
-  esac
-elif [ -f /etc/os-release ]; then
-  RELEASE=$(cat /etc/os-release | grep VERSION)
-  echo "Detected OpenSuse Linux '$RELEASE'"
-  case $RELEASE in
-    *"13.2"*)
-    echo "Installing libvips dependencies via zypper"
-    zypper --gpg-auto-import-keys install -y --type pattern devel_basis
-    zypper --gpg-auto-import-keys install -y tar curl gtk-doc libxml2-devel libjpeg-turbo libjpeg8-devel libpng16-devel libtiff-devel libexif-devel liblcms2-devel ImageMagick-devel gobject-introspection-devel libwebp-devel
-    install_libvips_from_source
-    ;;
-  esac
-elif [ -f /etc/SuSE-brand ]; then
-  RELEASE=$(cat /etc/SuSE-brand | grep VERSION)
-  echo "Detected OpenSuse Linux '$RELEASE'"
-  case $RELEASE in
-    *"13.1")
-    echo "Installing libvips dependencies via zypper"
-    zypper --gpg-auto-import-keys install -y --type pattern devel_basis
-    zypper --gpg-auto-import-keys install -y tar curl gtk-doc libxml2-devel libjpeg-turbo libjpeg8-devel libpng16-devel libtiff-devel libexif-devel liblcms2-devel ImageMagick-devel gobject-introspection-devel libwebp-devel
-    install_libvips_from_source
-    ;;
-  esac
-else
-  # Unsupported OS
-  sorry "vips" "$(uname -a)"
-fi

src/common.cc

@@ -1,12 +1,27 @@
+// 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 <cstdlib>
 #include <string>
 #include <string.h>
+#include <vector>
 
 #include <node.h>
 #include <node_buffer.h>
+#include <nan.h>
 #include <vips/vips8>
 
-#include "nan.h"
 #include "common.h"
 
 using vips::VImage;
@@ -254,8 +269,7 @@ namespace sharp {
     return (
       (bands == 2 && interpretation == VIPS_INTERPRETATION_B_W) ||
       (bands == 4 && interpretation != VIPS_INTERPRETATION_CMYK) ||
-      (bands == 5 && interpretation == VIPS_INTERPRETATION_CMYK)
-    );
+      (bands == 5 && interpretation == VIPS_INTERPRETATION_CMYK));
   }
 
   /*
@@ -263,11 +277,8 @@ namespace sharp {
   */
   int ExifOrientation(VImage image) {
     int orientation = 0;
-    if (image.get_typeof(EXIF_IFD0_ORIENTATION) != 0) {
-      char const *exif = image.get_string(EXIF_IFD0_ORIENTATION);
-      if (exif != nullptr) {
-        orientation = atoi(&exif[0]);
-      }
+    if (image.get_typeof(VIPS_META_ORIENTATION) != 0) {
+      orientation = image.get_int(VIPS_META_ORIENTATION);
     }
     return orientation;
   }
@@ -276,16 +287,14 @@ namespace sharp {
     Set EXIF Orientation of image.
   */
   void SetExifOrientation(VImage image, int const orientation) {
-    char exif[3];
-    g_snprintf(exif, sizeof(exif), "%d", orientation);
-    image.set(EXIF_IFD0_ORIENTATION, exif);
+    image.set(VIPS_META_ORIENTATION, orientation);
   }
 
   /*
     Remove EXIF Orientation from image.
   */
   void RemoveExifOrientation(VImage image) {
-    SetExifOrientation(image, 0);
+    vips_image_remove(image.get_image(), VIPS_META_ORIENTATION);
   }
 
   /*
@@ -383,23 +392,23 @@ namespace sharp {
     int top = 0;
 
     // assign only if valid
-    if(x >= 0 && x < (inWidth - outWidth)) {
+    if (x >= 0 && x < (inWidth - outWidth)) {
       left = x;
-    } else if(x >= (inWidth - outWidth)) {
+    } else if (x >= (inWidth - outWidth)) {
       left = inWidth - outWidth;
     }
 
-    if(y >= 0 && y < (inHeight - outHeight)) {
+    if (y >= 0 && y < (inHeight - outHeight)) {
       top = y;
-    } else if(y >= (inHeight - outHeight)) {
+    } else if (y >= (inHeight - outHeight)) {
       top = inHeight - outHeight;
     }
 
     // the resulting left and top could have been outside the image after calculation from bottom/right edges
-    if(left < 0) {
+    if (left < 0) {
       left = 0;
     }
-    if(top < 0) {
+    if (top < 0) {
       top = 0;
     }
 
@@ -426,8 +435,7 @@ namespace sharp {
   */
   VipsOperationBoolean GetBooleanOperation(std::string const opStr) {
     return static_cast<VipsOperationBoolean>(
-      vips_enum_from_nick(nullptr, VIPS_TYPE_OPERATION_BOOLEAN, opStr.data())
-    );
+      vips_enum_from_nick(nullptr, VIPS_TYPE_OPERATION_BOOLEAN, opStr.data()));
   }
 
   /*
@@ -435,8 +443,23 @@ namespace sharp {
   */
   VipsInterpretation GetInterpretation(std::string const typeStr) {
     return static_cast<VipsInterpretation>(
-      vips_enum_from_nick(nullptr, VIPS_TYPE_INTERPRETATION, typeStr.data())
-    );
+      vips_enum_from_nick(nullptr, VIPS_TYPE_INTERPRETATION, typeStr.data()));
+  }
+
+  /*
+    Convert RGBA value to another colourspace
+  */
+  std::vector<double> GetRgbaAsColourspace(std::vector<double> const rgba, VipsInterpretation const interpretation) {
+    int const bands = static_cast<int>(rgba.size());
+    if (bands < 3 || interpretation == VIPS_INTERPRETATION_sRGB || interpretation == VIPS_INTERPRETATION_RGB) {
+      return rgba;
+    } else {
+      VImage pixel = VImage::new_matrix(1, 1);
+      pixel.set("bands", bands);
+      pixel = pixel.new_from_image(rgba);
+      pixel = pixel.colourspace(interpretation, VImage::option()->set("source_space", VIPS_INTERPRETATION_sRGB));
+      return pixel(0, 0);
+    }
   }
 
 }  // namespace sharp

src/common.h

@@ -1,18 +1,32 @@
+// 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_COMMON_H_
 #define SRC_COMMON_H_
 
 #include <string>
 #include <tuple>
+#include <vector>
 
 #include <node.h>
+#include <nan.h>
 #include <vips/vips8>
 
-#include "nan.h"
-
 // Verify platform and compiler compatibility
 
-#if (VIPS_MAJOR_VERSION < 8 || (VIPS_MAJOR_VERSION == 8 && VIPS_MINOR_VERSION < 3))
-#error libvips version 8.3.x required - see sharp.dimens.io/page/install
+#if (VIPS_MAJOR_VERSION < 8 || (VIPS_MAJOR_VERSION == 8 && VIPS_MINOR_VERSION < 4))
+#error libvips version 8.4.x required - see sharp.dimens.io/page/install
 #endif
 
 #if ((!defined(__clang__)) && defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 6)))
@@ -25,8 +39,6 @@
 #endif
 #endif
 
-#define EXIF_IFD0_ORIENTATION "exif-ifd0-Orientation"
-
 using vips::VImage;
 
 namespace sharp {
@@ -65,8 +77,7 @@ 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,
@@ -201,6 +212,11 @@ namespace sharp {
   */
   VipsInterpretation GetInterpretation(std::string const typeStr);
 
+  /*
+    Convert RGBA value to another colourspace
+  */
+  std::vector<double> GetRgbaAsColourspace(std::vector<double> const rgba, VipsInterpretation const interpretation);
+
 }  // namespace sharp
 
 #endif  // SRC_COMMON_H_

src/libvips/cplusplus/VImage.cpp

@@ -2,6 +2,10 @@
  *
  * 30/12/14
  * 	- allow set enum value from string
+ * 10/6/16
+ * 	- missing implementation of VImage::write()
+ * 11/6/16
+ * 	- added arithmetic assignment overloads, += etc. 
  */
 
 /*
@@ -457,7 +461,7 @@ VImage::call_option_string( const char *operation_name,
 {
 	VipsOperation *operation;
 
-	VIPS_DEBUG_MSG( "vips_call_by_name: starting for %s ...\n", 
+	VIPS_DEBUG_MSG( "call_option_string: starting for %s ...\n", 
 		operation_name );
 
 	if( !(operation = vips_operation_new( operation_name )) ) {
@@ -485,6 +489,7 @@ VImage::call_option_string( const char *operation_name,
 	 */
 	if( vips_cache_operation_buildp( &operation ) ) {
 		vips_object_unref_outputs( VIPS_OBJECT( operation ) );
+		g_object_unref( operation ); 
 		delete options; 
 		throw( VError() ); 
 	}
@@ -566,7 +571,7 @@ VImage::new_from_image( std::vector<double> pixel )
 	VImage onepx = VImage::black( 1, 1, 
 		VImage::option()->set( "bands", bands() ) ); 
 
-	onepx = onepx.linear( to_vectorv( 1, 1.0 ), pixel ).cast( format() );
+	onepx = (onepx + pixel).cast( format() );
 
 	VImage big = onepx.embed( 0, 0, width(), height(), 
 		VImage::option()->set( "extend", VIPS_EXTEND_COPY ) ); 
@@ -612,6 +617,15 @@ VImage::new_matrixv( int width, int height, ... )
 	return( matrix ); 
 }
 
+VImage
+VImage::write( VImage out )
+{
+	if( vips_image_write( this->get_image(), out.get_image() ) )
+		throw VError(); 
+
+	return( out ); 
+}
+
 void 
 VImage::write_to_file( const char *name, VOption *options )
 {
@@ -755,13 +769,32 @@ operator+( VImage a, std::vector<double> b )
 	return( a.linear( 1.0, b ) ); 
 }
 
+VImage & 
+operator+=( VImage a, const VImage b )
+{
+	return( a = a + b ); 
+}
+
+VImage & 
+operator+=( VImage a, const double b )
+{
+	return( a = a + b ); 
+}
+
+VImage & 
+operator+=( VImage a, std::vector<double> b )
+{
+	return( a = a + b ); 
+}
+
 VImage 
 operator-( VImage a, VImage b ) 
 {
 	return( a.subtract( b ) );
 }
 
-VImage operator-( double a, VImage b ) 
+VImage 
+operator-( double a, VImage b ) 
 {
 	return( b.linear( -1.0, a ) ); 
 }
@@ -784,6 +817,24 @@ operator-( VImage a, std::vector<double> b )
 	return( a.linear( 1.0, vips::negate( b ) ) ); 
 }
 
+VImage & 
+operator-=( VImage a, const VImage b )
+{
+	return( a = a - b ); 
+}
+
+VImage & 
+operator-=( VImage a, const double b )
+{
+	return( a = a - b ); 
+}
+
+VImage & 
+operator-=( VImage a, std::vector<double> b )
+{
+	return( a = a - b ); 
+}
+
 VImage 
 operator-( VImage a ) 
 { 
@@ -820,6 +871,24 @@ operator*( VImage a, std::vector<double> b )
 	return( a.linear( b, 0.0 ) ); 
 }
 
+VImage & 
+operator*=( VImage a, const VImage b )
+{
+	return( a = a * b ); 
+}
+
+VImage & 
+operator*=( VImage a, const double b )
+{
+	return( a = a * b ); 
+}
+
+VImage & 
+operator*=( VImage a, std::vector<double> b )
+{
+	return( a = a * b ); 
+}
+
 VImage 
 operator/( VImage a, VImage b ) 
 {
@@ -850,6 +919,24 @@ operator/( VImage a, std::vector<double> b )
 	return( a.linear( vips::invert( b ), 0.0 ) ); 
 }
 
+VImage & 
+operator/=( VImage a, const VImage b )
+{
+	return( a = a / b ); 
+}
+
+VImage & 
+operator/=( VImage a, const double b )
+{
+	return( a = a / b ); 
+}
+
+VImage & 
+operator/=( VImage a, std::vector<double> b )
+{
+	return( a = a / b ); 
+}
+
 VImage 
 operator%( VImage a, VImage b ) 
 {
@@ -868,6 +955,24 @@ operator%( VImage a, std::vector<double> b )
 	return( a.remainder_const( b ) ); 
 }
 
+VImage & 
+operator%=( VImage a, const VImage b )
+{
+	return( a = a % b ); 
+}
+
+VImage & 
+operator%=( VImage a, const double b )
+{
+	return( a = a % b ); 
+}
+
+VImage & 
+operator%=( VImage a, std::vector<double> b )
+{
+	return( a = a % b ); 
+}
+
 VImage 
 operator<( VImage a, VImage b ) 
 {
@@ -1104,6 +1209,24 @@ operator&( VImage a, std::vector<double> b )
 	return( a.boolean_const( b, VIPS_OPERATION_BOOLEAN_AND ) );
 }
 
+VImage & 
+operator&=( VImage a, const VImage b )
+{
+	return( a = a & b ); 
+}
+
+VImage & 
+operator&=( VImage a, const double b )
+{
+	return( a = a & b ); 
+}
+
+VImage & 
+operator&=( VImage a, std::vector<double> b )
+{
+	return( a = a & b ); 
+}
+
 VImage 
 operator|( VImage a, VImage b ) 
 {
@@ -1136,6 +1259,24 @@ operator|( VImage a, std::vector<double> b )
 	return( a.boolean_const( b, VIPS_OPERATION_BOOLEAN_OR ) );
 }
 
+VImage & 
+operator|=( VImage a, const VImage b )
+{
+	return( a = a | b ); 
+}
+
+VImage & 
+operator|=( VImage a, const double b )
+{
+	return( a = a | b ); 
+}
+
+VImage & 
+operator|=( VImage a, std::vector<double> b )
+{
+	return( a = a | b ); 
+}
+
 VImage 
 operator^( VImage a, VImage b ) 
 {
@@ -1168,6 +1309,24 @@ operator^( VImage a, std::vector<double> b )
 	return( a.boolean_const( b, VIPS_OPERATION_BOOLEAN_EOR ) );
 }
 
+VImage & 
+operator^=( VImage a, const VImage b )
+{
+	return( a = a ^ b ); 
+}
+
+VImage & 
+operator^=( VImage a, const double b )
+{
+	return( a = a ^ b ); 
+}
+
+VImage & 
+operator^=( VImage a, std::vector<double> b )
+{
+	return( a = a ^ b ); 
+}
+
 VImage 
 operator<<( VImage a, VImage b ) 
 {
@@ -1187,6 +1346,24 @@ operator<<( VImage a, std::vector<double> b )
 	return( a.boolean_const( b, VIPS_OPERATION_BOOLEAN_LSHIFT ) ); 
 }
 
+VImage & 
+operator<<=( VImage a, const VImage b )
+{
+	return( a = a << b ); 
+}
+
+VImage & 
+operator<<=( VImage a, const double b )
+{
+	return( a = a << b ); 
+}
+
+VImage & 
+operator<<=( VImage a, std::vector<double> b )
+{
+	return( a = a << b ); 
+}
+
 VImage 
 operator>>( VImage a, VImage b ) 
 {
@@ -1206,4 +1383,22 @@ operator>>( VImage a, std::vector<double> b )
 	return( a.boolean_const( b, VIPS_OPERATION_BOOLEAN_RSHIFT ) ); 
 }
 
+VImage & 
+operator>>=( VImage a, const VImage b )
+{
+	return( a = a << b ); 
+}
+
+VImage & 
+operator>>=( VImage a, const double b )
+{
+	return( a = a << b ); 
+}
+
+VImage & 
+operator>>=( VImage a, std::vector<double> b )
+{
+	return( a = a << b ); 
+}
+
 VIPS_NAMESPACE_END

src/libvips/cplusplus/vips-operators.cpp

@@ -1,5 +1,5 @@
 // bodies for vips operations
-// Fri Feb 12 20:03:53 GMT 2016
+// Thu 18 Aug 16:01:57 BST 2016
 // this file is generated automatically, do not edit!
 
 void VImage::system( char * cmd_format , VOption *options )
@@ -1321,26 +1321,28 @@ VImage VImage::fractsurf( int width , int height , double fractal_dimension , VO
     return( out );
 }
 
-VImage VImage::radload( char * filename , VOption *options )
+VImage VImage::worley( int width , int height , VOption *options )
 {
     VImage out;
 
-    call( "radload" ,
+    call( "worley" ,
         (options ? options : VImage::option()) ->
-            set( "filename", filename ) ->
-            set( "out", &out ) );
+            set( "out", &out ) ->
+            set( "width", width ) ->
+            set( "height", height ) );
 
     return( out );
 }
 
-VImage VImage::ppmload( char * filename , VOption *options )
+VImage VImage::perlin( int width , int height , VOption *options )
 {
     VImage out;
 
-    call( "ppmload" ,
+    call( "perlin" ,
         (options ? options : VImage::option()) ->
-            set( "filename", filename ) ->
-            set( "out", &out ) );
+            set( "out", &out ) ->
+            set( "width", width ) ->
+            set( "height", height ) );
 
     return( out );
 }
@@ -1369,18 +1371,6 @@ VImage VImage::matrixload( char * filename , VOption *options )
     return( out );
 }
 
-VImage VImage::analyzeload( char * filename , VOption *options )
-{
-    VImage out;
-
-    call( "analyzeload" ,
-        (options ? options : VImage::option()) ->
-            set( "filename", filename ) ->
-            set( "out", &out ) );
-
-    return( out );
-}
-
 VImage VImage::rawload( char * filename , int width , int height , int bands , VOption *options )
 {
     VImage out;
@@ -1408,6 +1398,42 @@ VImage VImage::vipsload( char * filename , VOption *options )
     return( out );
 }
 
+VImage VImage::analyzeload( char * filename , VOption *options )
+{
+    VImage out;
+
+    call( "analyzeload" ,
+        (options ? options : VImage::option()) ->
+            set( "filename", filename ) ->
+            set( "out", &out ) );
+
+    return( out );
+}
+
+VImage VImage::ppmload( char * filename , VOption *options )
+{
+    VImage out;
+
+    call( "ppmload" ,
+        (options ? options : VImage::option()) ->
+            set( "filename", filename ) ->
+            set( "out", &out ) );
+
+    return( out );
+}
+
+VImage VImage::radload( char * filename , VOption *options )
+{
+    VImage out;
+
+    call( "radload" ,
+        (options ? options : VImage::option()) ->
+            set( "filename", filename ) ->
+            set( "out", &out ) );
+
+    return( out );
+}
+
 VImage VImage::pdfload( char * filename , VOption *options )
 {
     VImage out;
@@ -1648,22 +1674,6 @@ VImage VImage::openexrload( char * filename , VOption *options )
     return( out );
 }
 
-void VImage::radsave( char * filename , VOption *options )
-{
-    call( "radsave" ,
-        (options ? options : VImage::option()) ->
-            set( "in", *this ) ->
-            set( "filename", filename ) );
-}
-
-void VImage::ppmsave( char * filename , VOption *options )
-{
-    call( "ppmsave" ,
-        (options ? options : VImage::option()) ->
-            set( "in", *this ) ->
-            set( "filename", filename ) );
-}
-
 void VImage::csvsave( char * filename , VOption *options )
 {
     call( "csvsave" ,
@@ -1711,6 +1721,34 @@ void VImage::vipssave( char * filename , VOption *options )
             set( "filename", filename ) );
 }
 
+void VImage::ppmsave( char * filename , VOption *options )
+{
+    call( "ppmsave" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "filename", filename ) );
+}
+
+void VImage::radsave( char * filename , VOption *options )
+{
+    call( "radsave" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "filename", filename ) );
+}
+
+VipsBlob * VImage::radsave_buffer( VOption *options )
+{
+    VipsBlob * buffer;
+
+    call( "radsave_buffer" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "buffer", &buffer ) );
+
+    return( buffer );
+}
+
 void VImage::dzsave( char * filename , VOption *options )
 {
     call( "dzsave" ,
@@ -1815,7 +1853,7 @@ VImage VImage::mapim( VImage index , VOption *options )
     return( out );
 }
 
-VImage VImage::shrink( double xshrink , double yshrink , VOption *options )
+VImage VImage::shrink( double hshrink , double vshrink , VOption *options )
 {
     VImage out;
 
@@ -1823,13 +1861,13 @@ VImage VImage::shrink( double xshrink , double yshrink , VOption *options )
         (options ? options : VImage::option()) ->
             set( "in", *this ) ->
             set( "out", &out ) ->
-            set( "xshrink", xshrink ) ->
-            set( "yshrink", yshrink ) );
+            set( "hshrink", hshrink ) ->
+            set( "vshrink", vshrink ) );
 
     return( out );
 }
 
-VImage VImage::shrinkh( int xshrink , VOption *options )
+VImage VImage::shrinkh( int hshrink , VOption *options )
 {
     VImage out;
 
@@ -1837,12 +1875,12 @@ VImage VImage::shrinkh( int xshrink , VOption *options )
         (options ? options : VImage::option()) ->
             set( "in", *this ) ->
             set( "out", &out ) ->
-            set( "xshrink", xshrink ) );
+            set( "hshrink", hshrink ) );
 
     return( out );
 }
 
-VImage VImage::shrinkv( int yshrink , VOption *options )
+VImage VImage::shrinkv( int vshrink , VOption *options )
 {
     VImage out;
 
@@ -1850,12 +1888,12 @@ VImage VImage::shrinkv( int yshrink , VOption *options )
         (options ? options : VImage::option()) ->
             set( "in", *this ) ->
             set( "out", &out ) ->
-            set( "yshrink", yshrink ) );
+            set( "vshrink", vshrink ) );
 
     return( out );
 }
 
-VImage VImage::reduceh( double xshrink , VOption *options )
+VImage VImage::reduceh( double hshrink , VOption *options )
 {
     VImage out;
 
@@ -1863,12 +1901,12 @@ VImage VImage::reduceh( double xshrink , VOption *options )
         (options ? options : VImage::option()) ->
             set( "in", *this ) ->
             set( "out", &out ) ->
-            set( "xshrink", xshrink ) );
+            set( "hshrink", hshrink ) );
 
     return( out );
 }
 
-VImage VImage::reducev( double yshrink , VOption *options )
+VImage VImage::reducev( double vshrink , VOption *options )
 {
     VImage out;
 
@@ -1876,12 +1914,12 @@ VImage VImage::reducev( double yshrink , VOption *options )
         (options ? options : VImage::option()) ->
             set( "in", *this ) ->
             set( "out", &out ) ->
-            set( "yshrink", yshrink ) );
+            set( "vshrink", vshrink ) );
 
     return( out );
 }
 
-VImage VImage::reduce( double xshrink , double yshrink , VOption *options )
+VImage VImage::reduce( double hshrink , double vshrink , VOption *options )
 {
     VImage out;
 
@@ -1889,8 +1927,8 @@ VImage VImage::reduce( double xshrink , double yshrink , VOption *options )
         (options ? options : VImage::option()) ->
             set( "in", *this ) ->
             set( "out", &out ) ->
-            set( "xshrink", xshrink ) ->
-            set( "yshrink", yshrink ) );
+            set( "hshrink", hshrink ) ->
+            set( "vshrink", vshrink ) );
 
     return( out );
 }
@@ -2475,6 +2513,45 @@ VImage VImage::conv( VImage mask , VOption *options )
     return( out );
 }
 
+VImage VImage::conva( VImage mask , VOption *options )
+{
+    VImage out;
+
+    call( "conva" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "out", &out ) ->
+            set( "mask", mask ) );
+
+    return( out );
+}
+
+VImage VImage::convf( VImage mask , VOption *options )
+{
+    VImage out;
+
+    call( "convf" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "out", &out ) ->
+            set( "mask", mask ) );
+
+    return( out );
+}
+
+VImage VImage::convi( VImage mask , VOption *options )
+{
+    VImage out;
+
+    call( "convi" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "out", &out ) ->
+            set( "mask", mask ) );
+
+    return( out );
+}
+
 VImage VImage::compass( VImage mask , VOption *options )
 {
     VImage out;
@@ -2501,6 +2578,19 @@ VImage VImage::convsep( VImage mask , VOption *options )
     return( out );
 }
 
+VImage VImage::convasep( VImage mask , VOption *options )
+{
+    VImage out;
+
+    call( "convasep" ,
+        (options ? options : VImage::option()) ->
+            set( "in", *this ) ->
+            set( "out", &out ) ->
+            set( "mask", mask ) );
+
+    return( out );
+}
+
 VImage VImage::fastcor( VImage ref , VOption *options )
 {
     VImage out;

src/metadata.cc

@@ -1,9 +1,24 @@
+// 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 <node.h>
+#include <nan.h>
 #include <vips/vips8>
 
-#include "nan.h"
 #include "common.h"
 #include "metadata.h"
 
@@ -11,15 +26,14 @@ class MetadataWorker : public Nan::AsyncWorker {
  public:
   MetadataWorker(
     Nan::Callback *callback, MetadataBaton *baton,
-    std::vector<v8::Local<v8::Object>> const buffersToPersist
-  ) : Nan::AsyncWorker(callback), baton(baton), buffersToPersist(buffersToPersist) {
+    std::vector<v8::Local<v8::Object>> const buffersToPersist)
+    : Nan::AsyncWorker(callback), baton(baton), buffersToPersist(buffersToPersist) {
     // Protect Buffer objects from GC, keyed on index
     std::accumulate(buffersToPersist.begin(), buffersToPersist.end(), 0,
       [this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
         SaveToPersistent(index, buffer);
         return index + 1;
-      }
-    );
+      });
   }
   ~MetadataWorker() {}
 
@@ -72,7 +86,7 @@ class MetadataWorker : public Nan::AsyncWorker {
     vips_thread_shutdown();
   }
 
-  void HandleOKCallback () {
+  void HandleOKCallback() {
     using Nan::New;
     using Nan::Set;
     Nan::HandleScope();
@@ -99,14 +113,12 @@ class MetadataWorker : public Nan::AsyncWorker {
       if (baton->exifLength > 0) {
         Set(info,
           New("exif").ToLocalChecked(),
-          Nan::NewBuffer(baton->exif, baton->exifLength, sharp::FreeCallback, nullptr).ToLocalChecked()
-        );
+          Nan::NewBuffer(baton->exif, baton->exifLength, sharp::FreeCallback, nullptr).ToLocalChecked());
       }
       if (baton->iccLength > 0) {
         Set(info,
           New("icc").ToLocalChecked(),
-          Nan::NewBuffer(baton->icc, baton->iccLength, sharp::FreeCallback, nullptr).ToLocalChecked()
-        );
+          Nan::NewBuffer(baton->icc, baton->iccLength, sharp::FreeCallback, nullptr).ToLocalChecked());
       }
       argv[1] = info;
     }
@@ -116,8 +128,7 @@ class MetadataWorker : public Nan::AsyncWorker {
       [this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
         GetFromPersistent(index);
         return index + 1;
-      }
-    );
+      });
     delete baton->input;
     delete baton;
 

src/metadata.h

@@ -1,8 +1,24 @@
+// 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_METADATA_H_
 #define SRC_METADATA_H_
 
-#include "nan.h"
-#include "common.h"
+#include <string>
+#include <nan.h>
+
+#include "./common.h"
 
 struct MetadataBaton {
   // Input

src/operations.cc

@@ -1,7 +1,23 @@
+// 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 <algorithm>
 #include <functional>
 #include <memory>
 #include <tuple>
+#include <vector>
+
 #include <vips/vips8>
 
 #include "common.h"
@@ -17,7 +33,7 @@ namespace sharp {
     Assumes alpha channels are already premultiplied and will be unpremultiplied after.
    */
   VImage Composite(VImage src, VImage dst, const int gravity) {
-    if(IsInputValidForComposition(src, dst)) {
+    if (IsInputValidForComposition(src, dst)) {
       // Enlarge overlay src, if required
       if (src.width() < dst.width() || src.height() < dst.height()) {
         // Calculate the (left, top) coordinates of the output image within the input image, applying the given gravity.
@@ -28,8 +44,7 @@ namespace sharp {
         std::vector<double> background { 0.0, 0.0, 0.0, 0.0 };
         src = src.embed(left, top, dst.width(), dst.height(), VImage::option()
           ->set("extend", VIPS_EXTEND_BACKGROUND)
-          ->set("background", background)
-        );
+          ->set("background", background));
       }
       return CompositeImage(src, dst);
     }
@@ -37,9 +52,8 @@ namespace sharp {
     return dst;
   }
 
-
   VImage Composite(VImage src, VImage dst, const int x, const int y) {
-    if(IsInputValidForComposition(src, dst)) {
+    if (IsInputValidForComposition(src, dst)) {
       // Enlarge overlay src, if required
       if (src.width() < dst.width() || src.height() < dst.height()) {
         // Calculate the (left, top) coordinates of the output image within the input image, applying the given gravity.
@@ -50,8 +64,7 @@ namespace sharp {
         std::vector<double> background { 0.0, 0.0, 0.0, 0.0 };
         src = src.embed(left, top, dst.width(), dst.height(), VImage::option()
           ->set("extend", VIPS_EXTEND_BACKGROUND)
-          ->set("background", background)
-        );
+          ->set("background", background));
       }
       return CompositeImage(src, dst);
     }
@@ -146,12 +159,11 @@ namespace sharp {
       std::vector<double> background { 0.0, 0.0, 0.0, 0.0 };
       mask = mask.embed(left, top, dst.width(), dst.height(), VImage::option()
               ->set("extend", VIPS_EXTEND_BACKGROUND)
-              ->set("background", background)
-      );
+              ->set("background", background));
     }
 
     // we use the mask alpha if it has alpha
-    if(maskHasAlpha) {
+    if (maskHasAlpha) {
       mask = mask.extract_band(mask.bands() - 1, VImage::option()->set("n", 1));;
     }
 
@@ -178,7 +190,7 @@ namespace sharp {
   /*
    * Stretch luminance to cover full dynamic range.
    */
-  VImage Normalize(VImage image) {
+  VImage Normalise(VImage image) {
     // Get original colourspace
     VipsInterpretation typeBeforeNormalize = image.interpretation();
     if (typeBeforeNormalize == VIPS_INTERPRETATION_RGB) {
@@ -285,8 +297,8 @@ namespace sharp {
         colourspaceBeforeSharpen = VIPS_INTERPRETATION_sRGB;
       }
       return image.sharpen(
-        VImage::option()->set("sigma", sigma)->set("m1", flat)->set("m2", jagged)
-      ).colourspace(colourspaceBeforeSharpen);
+        VImage::option()->set("sigma", sigma)->set("m1", flat)->set("m2", jagged))
+        .colourspace(colourspaceBeforeSharpen);
     }
   }
 
@@ -301,6 +313,12 @@ namespace sharp {
     Calculate the intensity of edges, skin tone and saturation
   */
   double AttentionStrategy::operator()(VImage image) {
+    // Flatten RGBA onto a mid-grey background
+    if (image.bands() == 4 && HasAlpha(image)) {
+      double const midgrey = sharp::Is16Bit(image.interpretation()) ? 32768.0 : 128.0;
+      std::vector<double> background { midgrey, midgrey, midgrey };
+      image = image.flatten(VImage::option()->set("background", background));
+    }
     // Convert to LAB colourspace
     VImage lab = image.colourspace(VIPS_INTERPRETATION_LAB);
     VImage l = lab[0];
@@ -410,12 +428,11 @@ namespace sharp {
       ->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)
-    );
+      ->set("threaded", TRUE));
   }
 
   VImage Threshold(VImage image, double const threshold, bool const thresholdGrayscale) {
-    if(!thresholdGrayscale) {
+    if (!thresholdGrayscale) {
       return image >= threshold;
     }
     return image.colourspace(VIPS_INTERPRETATION_B_W) >= threshold;
@@ -480,7 +497,7 @@ namespace sharp {
     int width = right - left;
     int height = bottom - top;
 
-    if(width <= 0 || height <= 0) {
+    if (width <= 0 || height <= 0) {
       throw VError("Unexpected error while trimming. Try to lower the tolerance");
     }
 

src/operations.h

@@ -1,3 +1,17 @@
+// 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_OPERATIONS_H_
 #define SRC_OPERATIONS_H_
 
@@ -41,7 +55,7 @@ namespace sharp {
   /*
    * Stretch luminance to cover full dynamic range.
    */
-  VImage Normalize(VImage image);
+  VImage Normalise(VImage image);
 
   /*
    * Gamma encoding/decoding
@@ -78,8 +92,7 @@ namespace sharp {
     Calculate crop area based on given strategy (Entropy, Attention)
   */
   std::tuple<int, int> Crop(
-    VImage image, int const outWidth, int const outHeight, std::function<double(VImage)> strategy
-  );
+    VImage image, int const outWidth, int const outHeight, std::function<double(VImage)> strategy);
 
   /*
     Insert a tile cache to prevent over-computation of any previous operations in the pipeline

src/pipeline.cc

@@ -1,15 +1,31 @@
+// 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 <algorithm>
 #include <cmath>
-#include <tuple>
-#include <utility>
+#include <map>
 #include <memory>
 #include <numeric>
-#include <map>
+#include <string>
+#include <tuple>
+#include <utility>
+#include <vector>
 
 #include <vips/vips8>
 #include <node.h>
+#include <nan.h>
 
-#include "nan.h"
 #include "common.h"
 #include "operations.h"
 #include "pipeline.h"
@@ -18,15 +34,14 @@ class PipelineWorker : public Nan::AsyncWorker {
  public:
   PipelineWorker(
     Nan::Callback *callback, PipelineBaton *baton, Nan::Callback *queueListener,
-    std::vector<v8::Local<v8::Object>> const buffersToPersist
-  ) : Nan::AsyncWorker(callback), baton(baton), queueListener(queueListener), buffersToPersist(buffersToPersist) {
+    std::vector<v8::Local<v8::Object>> const buffersToPersist)
+    : Nan::AsyncWorker(callback), baton(baton), queueListener(queueListener), 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;
-      }
-    );
+      });
   }
   ~PipelineWorker() {}
 
@@ -84,7 +99,7 @@ class PipelineWorker : public Nan::AsyncWorker {
       }
 
       // Trim
-      if(baton->trimTolerance != 0) {
+      if (baton->trimTolerance != 0) {
         image = sharp::Trim(image, baton->trimTolerance);
       }
 
@@ -277,8 +292,7 @@ class PipelineWorker : public Nan::AsyncWorker {
           image = image.icc_transform(
             const_cast<char*>(profileMap[VIPS_INTERPRETATION_sRGB].data()), VImage::option()
             ->set("embedded", TRUE)
-            ->set("intent", VIPS_INTENT_PERCEPTUAL)
-          );
+            ->set("intent", VIPS_INTENT_PERCEPTUAL));
         } catch(...) {
           // Ignore failure of embedded profile
         }
@@ -286,13 +300,9 @@ class PipelineWorker : public Nan::AsyncWorker {
         image = image.icc_transform(
           const_cast<char*>(profileMap[VIPS_INTERPRETATION_sRGB].data()), VImage::option()
           ->set("input_profile", profileMap[VIPS_INTERPRETATION_CMYK].data())
-          ->set("intent", VIPS_INTENT_PERCEPTUAL)
-        );
+          ->set("intent", VIPS_INTENT_PERCEPTUAL));
       }
 
-      // Calculate maximum alpha value based on input image pixel depth
-      double const maxAlpha = sharp::MaximumImageAlpha(image.interpretation());
-
       // Flatten image to remove alpha channel
       if (baton->flatten && HasAlpha(image)) {
         // Scale up 8-bit values to match 16-bit input image
@@ -304,9 +314,7 @@ class PipelineWorker : public Nan::AsyncWorker {
           baton->background[2] * multiplier
         };
         image = image.flatten(VImage::option()
-          ->set("background", background)
-          ->set("max_alpha", maxAlpha)
-        );
+          ->set("background", background));
       }
 
       // Negate the colours in the image
@@ -324,7 +332,32 @@ class PipelineWorker : public Nan::AsyncWorker {
         image = image.colourspace(VIPS_INTERPRETATION_B_W);
       }
 
-      if (xshrink > 1 || yshrink > 1) {
+      // Ensure image has an alpha channel when there is an overlay
+      bool hasOverlay = baton->overlay != nullptr;
+      if (hasOverlay && !HasAlpha(image)) {
+        double const multiplier = sharp::Is16Bit(image.interpretation()) ? 256.0 : 1.0;
+        image = image.bandjoin(
+          VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier));
+      }
+
+      bool const shouldShrink = xshrink > 1 || yshrink > 1;
+      bool const shouldReduce = xresidual != 1.0 || yresidual != 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 shouldCutout = baton->overlayCutout;
+      bool const shouldPremultiplyAlpha = HasAlpha(image) &&
+        (shouldShrink || shouldReduce || shouldBlur || shouldConv || shouldSharpen || (hasOverlay && !shouldCutout));
+
+      // Premultiply image alpha channel before all transformations to avoid
+      // dark fringing around bright pixels
+      // See: http://entropymine.com/imageworsener/resizealpha/
+      if (shouldPremultiplyAlpha) {
+        image = image.premultiply();
+      }
+
+      // Fast, integral box-shrink
+      if (shouldShrink) {
         if (yshrink > 1) {
           image = image.shrinkv(yshrink);
         }
@@ -349,32 +382,8 @@ class PipelineWorker : public Nan::AsyncWorker {
         }
       }
 
-      // Ensure image has an alpha channel when there is an overlay
-      bool hasOverlay = baton->overlay != nullptr;
-      if (hasOverlay && !HasAlpha(image)) {
-        double const multiplier = sharp::Is16Bit(image.interpretation()) ? 256.0 : 1.0;
-        image = image.bandjoin(
-          VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier)
-        );
-      }
-
-      bool shouldAffineTransform = xresidual != 1.0 || yresidual != 1.0;
-      bool shouldBlur = baton->blurSigma != 0.0;
-      bool shouldConv = baton->convKernelWidth * baton->convKernelHeight > 0;
-      bool shouldSharpen = baton->sharpenSigma != 0.0;
-      bool shouldCutout = baton->overlayCutout;
-      bool shouldPremultiplyAlpha = HasAlpha(image) &&
-        (shouldAffineTransform || shouldBlur || shouldConv || shouldSharpen || (hasOverlay && !shouldCutout));
-
-      // Premultiply image alpha channel before all transformations to avoid
-      // dark fringing around bright pixels
-      // See: http://entropymine.com/imageworsener/resizealpha/
-      if (shouldPremultiplyAlpha) {
-        image = image.premultiply(VImage::option()->set("max_alpha", maxAlpha));
-      }
-
       // Use affine increase or kernel reduce with the remaining float part
-      if (shouldAffineTransform) {
+      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);
@@ -382,16 +391,19 @@ class PipelineWorker : public Nan::AsyncWorker {
         // 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())
-          );
+            vips_enum_from_nick(nullptr, VIPS_TYPE_KERNEL, baton->kernel.data()));
           if (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));
+            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));
+            image = image.reduceh(1.0 / xresidual, VImage::option()
+              ->set("kernel", kernel)
+              ->set("centre", baton->centreSampling));
           }
         }
         // Perform affine enlargement
@@ -399,13 +411,11 @@ class PipelineWorker : public Nan::AsyncWorker {
           vips::VInterpolate interpolator = vips::VInterpolate::new_from_name(baton->interpolator.data());
           if (yresidual > 1.0) {
             image = image.affine({1.0, 0.0, 0.0, yresidual}, VImage::option()
-              ->set("interpolate", interpolator)
-            );
+              ->set("interpolate", interpolator));
           }
           if (xresidual > 1.0) {
             image = image.affine({xresidual, 0.0, 0.0, 1.0}, VImage::option()
-              ->set("interpolate", interpolator)
-            );
+              ->set("interpolate", interpolator));
           }
         }
       }
@@ -429,13 +439,12 @@ class PipelineWorker : public Nan::AsyncWorker {
       }
 
       // Join additional color channels to the image
-      if(baton->joinChannelIn.size() > 0) {
+      if (baton->joinChannelIn.size() > 0) {
         VImage joinImage;
         ImageType joinImageType = ImageType::UNKNOWN;
 
-        for(unsigned int i = 0; i < baton->joinChannelIn.size(); i++) {
+        for (unsigned int i = 0; i < baton->joinChannelIn.size(); i++) {
           std::tie(joinImage, joinImageType) = sharp::OpenInput(baton->joinChannelIn[i], baton->accessMethod);
-
           image = image.bandjoin(joinImage);
         }
         image = image.copy(VImage::option()->set("interpretation", baton->colourspace));
@@ -459,26 +468,26 @@ class PipelineWorker : public Nan::AsyncWorker {
             background = { multiplier * (
               0.2126 * baton->background[0] +
               0.7152 * baton->background[1] +
-              0.0722 * baton->background[2]
-            )};
+              0.0722 * baton->background[2])
+            };
           }
           // Add alpha channel to background colour
           if (baton->background[3] < 255.0 || HasAlpha(image)) {
             background.push_back(baton->background[3] * multiplier);
           }
+          // Ensure background colour uses correct colourspace
+          background = sharp::GetRgbaAsColourspace(background, image.interpretation());
           // Add non-transparent alpha channel, if required
           if (baton->background[3] < 255.0 && !HasAlpha(image)) {
             image = image.bandjoin(
-              VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier)
-            );
+              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()
             ->set("extend", VIPS_EXTEND_BACKGROUND)
-            ->set("background", background)
-          );
+            ->set("background", background));
         } else if (baton->canvas != Canvas::IGNORE_ASPECT) {
           // Crop/max/min
           int left;
@@ -486,8 +495,7 @@ class PipelineWorker : public Nan::AsyncWorker {
           if (baton->crop < 9) {
             // Gravity-based crop
             std::tie(left, top) = sharp::CalculateCrop(
-              image.width(), image.height(), baton->width, baton->height, baton->crop
-            );
+              image.width(), image.height(), baton->width, baton->height, baton->crop);
           } else if (baton->crop == 16) {
             // Entropy-based crop
             std::tie(left, top) = sharp::Crop(image, baton->width, baton->height, sharp::EntropyStrategy());
@@ -506,8 +514,7 @@ class PipelineWorker : public Nan::AsyncWorker {
       // Post extraction
       if (baton->topOffsetPost != -1) {
         image = image.extract_area(
-          baton->leftOffsetPost, baton->topOffsetPost, baton->widthPost, baton->heightPost
-        );
+          baton->leftOffsetPost, baton->topOffsetPost, baton->widthPost, baton->heightPost);
       }
 
       // Extend edges
@@ -515,20 +522,31 @@ class PipelineWorker : public Nan::AsyncWorker {
         // Scale up 8-bit values to match 16-bit input image
         double const multiplier = sharp::Is16Bit(image.interpretation()) ? 256.0 : 1.0;
         // Create background colour
-        std::vector<double> background {
-          baton->background[0] * multiplier,
-          baton->background[1] * multiplier,
-          baton->background[2] * multiplier
-        };
+        std::vector<double> background;
+        if (image.bands() > 2) {
+          background = {
+            multiplier * baton->background[0],
+            multiplier * baton->background[1],
+            multiplier * baton->background[2]
+          };
+        } else {
+          // Convert sRGB to greyscale
+          background = { multiplier * (
+            0.2126 * baton->background[0] +
+            0.7152 * baton->background[1] +
+            0.0722 * baton->background[2])
+          };
+        }
         // Add alpha channel to background colour
         if (baton->background[3] < 255.0 || HasAlpha(image)) {
           background.push_back(baton->background[3] * multiplier);
         }
+        // Ensure background colour uses correct colourspace
+        background = sharp::GetRgbaAsColourspace(background, image.interpretation());
         // Add non-transparent alpha channel, if required
         if (baton->background[3] < 255.0 && !HasAlpha(image)) {
           image = image.bandjoin(
-            VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier)
-          );
+            VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier));
         }
         // Embed
         baton->width = image.width() + baton->extendLeft + baton->extendRight;
@@ -553,8 +571,7 @@ class PipelineWorker : public Nan::AsyncWorker {
         image = sharp::Convolve(image,
           baton->convKernelWidth, baton->convKernelHeight,
           baton->convKernelScale, baton->convKernelOffset,
-          baton->convKernel
-        );
+          baton->convKernel);
       }
 
       // Sharpen
@@ -588,17 +605,13 @@ class PipelineWorker : public Nan::AsyncWorker {
               // the overlayX/YOffsets will now be used to CalculateCrop for extract_area
               std::tie(left, top) = sharp::CalculateCrop(
                 overlayImage.width(), overlayImage.height(), image.width(), image.height(),
-                baton->overlayXOffset, baton->overlayYOffset
-              );
+                baton->overlayXOffset, baton->overlayYOffset);
             } else {
               // the overlayGravity will now be used to CalculateCrop for extract_area
               std::tie(left, top) = sharp::CalculateCrop(
-                overlayImage.width(), overlayImage.height(), image.width(), image.height(), baton->overlayGravity
-              );
+                overlayImage.width(), overlayImage.height(), image.width(), image.height(), baton->overlayGravity);
             }
-            overlayImage = overlayImage.extract_area(
-              left, top, image.width(), image.height()
-            );
+            overlayImage = overlayImage.extract_area(left, top, image.width(), image.height());
           }
           // the overlayGravity was used for extract_area, therefore set it back to its default value of 0
           baton->overlayGravity = 0;
@@ -611,15 +624,13 @@ class PipelineWorker : public Nan::AsyncWorker {
           if (!HasAlpha(overlayImage)) {
             double const multiplier = sharp::Is16Bit(overlayImage.interpretation()) ? 256.0 : 1.0;
             overlayImage = overlayImage.bandjoin(
-              VImage::new_matrix(overlayImage.width(), overlayImage.height()).new_from_image(255 * multiplier)
-            );
+              VImage::new_matrix(overlayImage.width(), overlayImage.height()).new_from_image(255 * multiplier));
           }
           // Ensure image has alpha channel
           if (!HasAlpha(image)) {
             double const multiplier = sharp::Is16Bit(image.interpretation()) ? 256.0 : 1.0;
             image = image.bandjoin(
-              VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier)
-            );
+              VImage::new_matrix(image.width(), image.height()).new_from_image(255 * multiplier));
           }
           // Ensure overlay is premultiplied sRGB
           overlayImage = overlayImage.colourspace(VIPS_INTERPRETATION_sRGB).premultiply();
@@ -635,7 +646,7 @@ class PipelineWorker : public Nan::AsyncWorker {
 
       // Reverse premultiplication after all transformations:
       if (shouldPremultiplyAlpha) {
-        image = image.unpremultiply(VImage::option()->set("max_alpha", maxAlpha));
+        image = image.unpremultiply();
         // Cast pixel values to integer
         if (sharp::Is16Bit(image.interpretation())) {
           image = image.cast(VIPS_FORMAT_USHORT);
@@ -649,9 +660,9 @@ class PipelineWorker : public Nan::AsyncWorker {
         image = sharp::Gamma(image, baton->gamma);
       }
 
-      // Apply normalization - stretch luminance to cover full dynamic range
-      if (baton->normalize) {
-        image = sharp::Normalize(image);
+      // Apply normalisation - stretch luminance to cover full dynamic range
+      if (baton->normalise) {
+        image = sharp::Normalise(image);
       }
 
       // Apply bitwise boolean operation between images
@@ -668,28 +679,24 @@ class PipelineWorker : public Nan::AsyncWorker {
       }
 
       // Extract an image channel (aka vips band)
-      if(baton->extractChannel > -1) {
-        if(baton->extractChannel >= image.bands()) {
+      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);
       }
-
       // Convert image to sRGB, if not already
       if (sharp::Is16Bit(image.interpretation())) {
         image = image.cast(VIPS_FORMAT_USHORT);
       }
       if (image.interpretation() != baton->colourspace) {
-        // Need to convert image
-        image = image.colourspace(baton->colourspace);
+        // Convert colourspace, pass the current known interpretation so libvips doesn't have to guess
+        image = image.colourspace(baton->colourspace, VImage::option()->set("source_space", image.interpretation()));
         // Transform colours from embedded profile to output profile
-        if (baton->withMetadata &&
-            sharp::HasProfile(image) &&
-            profileMap[baton->colourspace] != std::string()) {
+        if (baton->withMetadata && sharp::HasProfile(image) && profileMap[baton->colourspace] != std::string()) {
           image = image.icc_transform(const_cast<char*>(profileMap[baton->colourspace].data()),
-            VImage::option()->set("embedded", TRUE)
-          );
+            VImage::option()->set("embedded", TRUE));
         }
       }
 
@@ -709,36 +716,34 @@ class PipelineWorker : public Nan::AsyncWorker {
           // Write JPEG to buffer
           VipsArea *area = VIPS_AREA(image.jpegsave_buffer(VImage::option()
             ->set("strip", !baton->withMetadata)
-            ->set("Q", baton->quality)
-            ->set("optimize_coding", TRUE)
-            ->set("no_subsample", baton->withoutChromaSubsampling)
-            ->set("trellis_quant", baton->trellisQuantisation)
-            ->set("overshoot_deringing", baton->overshootDeringing)
-            ->set("optimize_scans", baton->optimiseScans)
-            ->set("interlace", baton->progressive)
-          ));
+            ->set("Q", baton->jpegQuality)
+            ->set("interlace", baton->jpegProgressive)
+            ->set("no_subsample", baton->jpegChromaSubsampling == "4:4:4")
+            ->set("trellis_quant", baton->jpegTrellisQuantisation)
+            ->set("overshoot_deringing", baton->jpegOvershootDeringing)
+            ->set("optimize_scans", baton->jpegOptimiseScans)
+            ->set("optimize_coding", TRUE)));
           baton->bufferOut = static_cast<char*>(area->data);
           baton->bufferOutLength = area->length;
           area->free_fn = nullptr;
           vips_area_unref(area);
           baton->formatOut = "jpeg";
-          if(baton->colourspace == VIPS_INTERPRETATION_CMYK) {
+          if (baton->colourspace == VIPS_INTERPRETATION_CMYK) {
             baton->channels = std::min(baton->channels, 4);
           } else {
             baton->channels = std::min(baton->channels, 3);
           }
-        } else if (baton->formatOut == "png" || (baton->formatOut == "input" && inputImageType == ImageType::PNG)) {
+        } else if (baton->formatOut == "png" || (baton->formatOut == "input" &&
+          (inputImageType == ImageType::PNG || inputImageType == ImageType::GIF || inputImageType == ImageType::SVG))) {
           // Strip profile
           if (!baton->withMetadata) {
             vips_image_remove(image.get_image(), VIPS_META_ICC_NAME);
           }
           // Write PNG to buffer
           VipsArea *area = VIPS_AREA(image.pngsave_buffer(VImage::option()
-            ->set("compression", baton->compressionLevel)
-            ->set("interlace", baton->progressive)
-            ->set("filter", baton->withoutAdaptiveFiltering ?
-              VIPS_FOREIGN_PNG_FILTER_NONE : VIPS_FOREIGN_PNG_FILTER_ALL)
-          ));
+            ->set("interlace", baton->pngProgressive)
+            ->set("compression", baton->pngCompressionLevel)
+            ->set("filter", baton->pngAdaptiveFiltering ? VIPS_FOREIGN_PNG_FILTER_ALL : VIPS_FOREIGN_PNG_FILTER_NONE)));
           baton->bufferOut = static_cast<char*>(area->data);
           baton->bufferOutLength = area->length;
           area->free_fn = nullptr;
@@ -748,8 +753,10 @@ class PipelineWorker : public Nan::AsyncWorker {
           // Write WEBP to buffer
           VipsArea *area = VIPS_AREA(image.webpsave_buffer(VImage::option()
             ->set("strip", !baton->withMetadata)
-            ->set("Q", baton->quality)
-          ));
+            ->set("Q", baton->webpQuality)
+            ->set("lossless", baton->webpLossless)
+            ->set("near_lossless", baton->webpNearLossless)
+            ->set("alpha_q", baton->webpAlphaQuality)));
           baton->bufferOut = static_cast<char*>(area->data);
           baton->bufferOutLength = area->length;
           area->free_fn = nullptr;
@@ -784,62 +791,93 @@ class PipelineWorker : public Nan::AsyncWorker {
         }
       } else {
         // File output
-        bool isJpeg = sharp::IsJpeg(baton->fileOut);
-        bool isPng = sharp::IsPng(baton->fileOut);
-        bool isWebp = sharp::IsWebp(baton->fileOut);
-        bool isTiff = sharp::IsTiff(baton->fileOut);
-        bool isDz = sharp::IsDz(baton->fileOut);
-        bool isDzZip = sharp::IsDzZip(baton->fileOut);
-        bool isV = sharp::IsV(baton->fileOut);
-        bool matchInput = baton->formatOut == "input" &&
+        bool const isJpeg = sharp::IsJpeg(baton->fileOut);
+        bool const isPng = sharp::IsPng(baton->fileOut);
+        bool const isWebp = sharp::IsWebp(baton->fileOut);
+        bool const isTiff = sharp::IsTiff(baton->fileOut);
+        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)) {
           // Write JPEG to file
           image.jpegsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
             ->set("strip", !baton->withMetadata)
-            ->set("Q", baton->quality)
-            ->set("optimize_coding", TRUE)
-            ->set("no_subsample", baton->withoutChromaSubsampling)
-            ->set("trellis_quant", baton->trellisQuantisation)
-            ->set("overshoot_deringing", baton->overshootDeringing)
-            ->set("optimize_scans", baton->optimiseScans)
-            ->set("interlace", baton->progressive)
-          );
+            ->set("Q", baton->jpegQuality)
+            ->set("interlace", baton->jpegProgressive)
+            ->set("no_subsample", baton->jpegChromaSubsampling == "4:4:4")
+            ->set("trellis_quant", baton->jpegTrellisQuantisation)
+            ->set("overshoot_deringing", baton->jpegOvershootDeringing)
+            ->set("optimize_scans", baton->jpegOptimiseScans)
+            ->set("optimize_coding", TRUE));
           baton->formatOut = "jpeg";
           baton->channels = std::min(baton->channels, 3);
-        } else if (baton->formatOut == "png" || isPng || (matchInput && inputImageType == ImageType::PNG)) {
+        } else if (baton->formatOut == "png" || isPng || (matchInput &&
+          (inputImageType == ImageType::PNG || inputImageType == ImageType::GIF || inputImageType == ImageType::SVG))) {
           // Strip profile
           if (!baton->withMetadata) {
             vips_image_remove(image.get_image(), VIPS_META_ICC_NAME);
           }
           // Write PNG to file
           image.pngsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
-            ->set("compression", baton->compressionLevel)
-            ->set("interlace", baton->progressive)
-            ->set("filter", baton->withoutAdaptiveFiltering ?
-              VIPS_FOREIGN_PNG_FILTER_NONE : VIPS_FOREIGN_PNG_FILTER_ALL)
-          );
+            ->set("interlace", baton->pngProgressive)
+            ->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)) {
           // Write WEBP to file
           image.webpsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
             ->set("strip", !baton->withMetadata)
-            ->set("Q", baton->quality)
-          );
+            ->set("Q", baton->webpQuality)
+            ->set("lossless", baton->webpLossless)
+            ->set("near_lossless", baton->webpNearLossless)
+            ->set("alpha_q", baton->webpAlphaQuality));
           baton->formatOut = "webp";
         } else if (baton->formatOut == "tiff" || isTiff || (matchInput && inputImageType == ImageType::TIFF)) {
           // Write TIFF to file
           image.tiffsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
             ->set("strip", !baton->withMetadata)
-            ->set("Q", baton->quality)
-            ->set("compression", VIPS_FOREIGN_TIFF_COMPRESSION_JPEG)
-          );
+            ->set("Q", baton->tiffQuality)
+            ->set("compression", VIPS_FOREIGN_TIFF_COMPRESSION_JPEG));
           baton->formatOut = "tiff";
           baton->channels = std::min(baton->channels, 3);
         } else if (baton->formatOut == "dz" || isDz || isDzZip) {
           if (isDzZip) {
             baton->tileContainer = VIPS_FOREIGN_DZ_CONTAINER_ZIP;
           }
+          // Forward format options through suffix
+          std::string suffix;
+          if (baton->tileFormat == "png") {
+            std::vector<std::pair<std::string, std::string>> options {
+              {"interlace", baton->pngProgressive ? "TRUE" : "FALSE"},
+              {"compression", std::to_string(baton->pngCompressionLevel)},
+              {"filter", baton->pngAdaptiveFiltering ? "all" : "none"}
+            };
+            suffix = AssembleSuffixString(".png", options);
+          } else if (baton->tileFormat == "webp") {
+            std::vector<std::pair<std::string, std::string>> options {
+              {"Q", std::to_string(baton->webpQuality)},
+              {"alpha_q", std::to_string(baton->webpAlphaQuality)},
+              {"lossless", baton->webpLossless ? "TRUE" : "FALSE"},
+              {"near_lossless", baton->webpNearLossless ? "TRUE" : "FALSE"}
+            };
+            suffix = AssembleSuffixString(".webp", options);
+          } else {
+            std::string extname = baton->tileLayout == VIPS_FOREIGN_DZ_LAYOUT_GOOGLE
+              || baton->tileLayout == VIPS_FOREIGN_DZ_LAYOUT_ZOOMIFY
+                ? ".jpg" : ".jpeg";
+            std::vector<std::pair<std::string, std::string>> options {
+              {"Q", std::to_string(baton->jpegQuality)},
+              {"interlace", baton->jpegProgressive ? "TRUE" : "FALSE"},
+              {"no_subsample", baton->jpegChromaSubsampling == "4:4:4" ? "TRUE": "FALSE"},
+              {"trellis_quant", baton->jpegTrellisQuantisation ? "TRUE" : "FALSE"},
+              {"overshoot_deringing", baton->jpegOvershootDeringing ? "TRUE": "FALSE"},
+              {"optimize_scans", baton->jpegOptimiseScans ? "TRUE": "FALSE"},
+              {"optimize_coding", "TRUE"}
+            };
+            suffix = AssembleSuffixString(extname, options);
+          }
           // Write DZ to file
           image.dzsave(const_cast<char*>(baton->fileOut.data()), VImage::option()
             ->set("strip", !baton->withMetadata)
@@ -847,13 +885,12 @@ class PipelineWorker : public Nan::AsyncWorker {
             ->set("overlap", baton->tileOverlap)
             ->set("container", baton->tileContainer)
             ->set("layout", baton->tileLayout)
-          );
+            ->set("suffix", const_cast<char*>(suffix.data())));
           baton->formatOut = "dz";
         } else if (baton->formatOut == "v" || isV || (matchInput && inputImageType == ImageType::VIPS)) {
           // Write V to file
           image.vipssave(const_cast<char*>(baton->fileOut.data()), VImage::option()
-            ->set("strip", !baton->withMetadata)
-          );
+            ->set("strip", !baton->withMetadata));
           baton->formatOut = "v";
         } else {
           // Unsupported output format
@@ -869,7 +906,7 @@ class PipelineWorker : public Nan::AsyncWorker {
     vips_thread_shutdown();
   }
 
-  void HandleOKCallback () {
+  void HandleOKCallback() {
     using Nan::New;
     using Nan::Set;
     Nan::HandleScope();
@@ -903,16 +940,17 @@ class PipelineWorker : public Nan::AsyncWorker {
       if (baton->bufferOutLength > 0) {
         // Pass ownership of output data to Buffer instance
         argv[1] = Nan::NewBuffer(
-          static_cast<char*>(baton->bufferOut), baton->bufferOutLength, sharp::FreeCallback, nullptr
-        ).ToLocalChecked();
+          static_cast<char*>(baton->bufferOut), baton->bufferOutLength, sharp::FreeCallback, nullptr)
+          .ToLocalChecked();
         // Add buffer size to info
         Set(info, New("size").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(baton->bufferOutLength)));
         argv[2] = info;
       } else {
         // Add file size to info
         GStatBuf st;
-        g_stat(baton->fileOut.data(), &st);
-        Set(info, New("size").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(st.st_size)));
+        if (g_stat(baton->fileOut.data(), &st) == 0) {
+          Set(info, New("size").ToLocalChecked(), New<v8::Uint32>(static_cast<uint32_t>(st.st_size)));
+        }
         argv[1] = info;
       }
     }
@@ -922,16 +960,14 @@ class PipelineWorker : public Nan::AsyncWorker {
       [this](uint32_t index, v8::Local<v8::Object> const buffer) -> uint32_t {
         GetFromPersistent(index);
         return index + 1;
-      }
-    );
+      });
     delete baton->input;
     delete baton->overlay;
     delete baton->boolean;
     for_each(baton->joinChannelIn.begin(), baton->joinChannelIn.end(),
       [this](sharp::InputDescriptor *joinChannelIn) {
         delete joinChannelIn;
-      }
-    );
+      });
     delete baton;
 
     // Decrement processing task counter
@@ -962,7 +998,7 @@ class PipelineWorker : public Nan::AsyncWorker {
     bool flip = FALSE;
     bool flop = FALSE;
     if (angle == -1) {
-      switch(sharp::ExifOrientation(image)) {
+      switch (sharp::ExifOrientation(image)) {
         case 6: rotate = VIPS_ANGLE_D90; break;
         case 3: rotate = VIPS_ANGLE_D180; break;
         case 8: rotate = VIPS_ANGLE_D270; break;
@@ -983,6 +1019,23 @@ class PipelineWorker : public Nan::AsyncWorker {
     return std::make_tuple(rotate, flip, flop);
   }
 
+  /*
+    Assemble the suffix argument to dzsave, which is the format (by extname)
+    alongisde comma-separated arguments to the corresponding `formatsave` vips
+    action.
+  */
+  std::string
+  AssembleSuffixString(std::string extname, std::vector<std::pair<std::string, std::string>> options) {
+    std::string argument;
+    for (auto const &option : options) {
+      if (!argument.empty()) {
+        argument += ",";
+      }
+      argument += option.first + "=" + option.second;
+    }
+    return extname + "[" + argument + "]";
+  }
+
   /*
     Clear all thread-local data.
   */
@@ -1063,13 +1116,14 @@ NAN_METHOD(pipeline) {
   baton->crop = AttrTo<int32_t>(options, "crop");
   baton->kernel = AttrAsStr(options, "kernel");
   baton->interpolator = AttrAsStr(options, "interpolator");
+  baton->centreSampling = AttrTo<bool>(options, "centreSampling");
   // Join Channel Options
-  if(HasAttr(options, "joinChannelIn")) {
+  if (HasAttr(options, "joinChannelIn")) {
     v8::Local<v8::Object> joinChannelObject = Nan::Get(options, Nan::New("joinChannelIn").ToLocalChecked())
       .ToLocalChecked().As<v8::Object>();
     v8::Local<v8::Array> joinChannelArray = joinChannelObject.As<v8::Array>();
     int joinChannelArrayLength = AttrTo<int32_t>(joinChannelObject, "length");
-    for(int i = 0; i < joinChannelArrayLength; i++) {
+    for (int i = 0; i < joinChannelArrayLength; i++) {
       baton->joinChannelIn.push_back(
         CreateInputDescriptor(
           Nan::Get(joinChannelArray, i).ToLocalChecked().As<v8::Object>(),
@@ -1086,12 +1140,12 @@ NAN_METHOD(pipeline) {
   baton->threshold = AttrTo<int32_t>(options, "threshold");
   baton->thresholdGrayscale = AttrTo<bool>(options, "thresholdGrayscale");
   baton->trimTolerance = AttrTo<int32_t>(options, "trimTolerance");
-  if(baton->accessMethod == VIPS_ACCESS_SEQUENTIAL && baton->trimTolerance != 0) {
+  if (baton->accessMethod == VIPS_ACCESS_SEQUENTIAL && baton->trimTolerance != 0) {
     baton->accessMethod = VIPS_ACCESS_RANDOM;
   }
   baton->gamma = AttrTo<double>(options, "gamma");
   baton->greyscale = AttrTo<bool>(options, "greyscale");
-  baton->normalize = AttrTo<bool>(options, "normalize");
+  baton->normalise = AttrTo<bool>(options, "normalise");
   baton->angle = AttrTo<int32_t>(options, "angle");
   baton->rotateBeforePreExtract = AttrTo<bool>(options, "rotateBeforePreExtract");
   baton->flip = AttrTo<bool>(options, "flip");
@@ -1121,23 +1175,30 @@ NAN_METHOD(pipeline) {
       baton->convKernel[i] = AttrTo<double>(kdata, i);
     }
   }
-  // Output options
-  baton->progressive = AttrTo<bool>(options, "progressive");
-  baton->quality = AttrTo<int32_t>(options, "quality");
-  baton->compressionLevel = AttrTo<int32_t>(options, "compressionLevel");
-  baton->withoutAdaptiveFiltering = AttrTo<bool>(options, "withoutAdaptiveFiltering");
-  baton->withoutChromaSubsampling = AttrTo<bool>(options, "withoutChromaSubsampling");
-  baton->trellisQuantisation = AttrTo<bool>(options, "trellisQuantisation");
-  baton->overshootDeringing = AttrTo<bool>(options, "overshootDeringing");
-  baton->optimiseScans = AttrTo<bool>(options, "optimiseScans");
-  baton->withMetadata = AttrTo<bool>(options, "withMetadata");
-  baton->withMetadataOrientation = AttrTo<uint32_t>(options, "withMetadataOrientation");
   baton->colourspace = sharp::GetInterpretation(AttrAsStr(options, "colourspace"));
-  if(baton->colourspace == VIPS_INTERPRETATION_ERROR)
+  if (baton->colourspace == VIPS_INTERPRETATION_ERROR) {
     baton->colourspace = VIPS_INTERPRETATION_sRGB;
+  }
   // Output
   baton->formatOut = AttrAsStr(options, "formatOut");
   baton->fileOut = AttrAsStr(options, "fileOut");
+  baton->withMetadata = AttrTo<bool>(options, "withMetadata");
+  baton->withMetadataOrientation = AttrTo<uint32_t>(options, "withMetadataOrientation");
+  // Format-specific
+  baton->jpegQuality = AttrTo<uint32_t>(options, "jpegQuality");
+  baton->jpegProgressive = AttrTo<bool>(options, "jpegProgressive");
+  baton->jpegChromaSubsampling = AttrAsStr(options, "jpegChromaSubsampling");
+  baton->jpegTrellisQuantisation = AttrTo<bool>(options, "jpegTrellisQuantisation");
+  baton->jpegOvershootDeringing = AttrTo<bool>(options, "jpegOvershootDeringing");
+  baton->jpegOptimiseScans = AttrTo<bool>(options, "jpegOptimiseScans");
+  baton->pngProgressive = AttrTo<bool>(options, "pngProgressive");
+  baton->pngCompressionLevel = AttrTo<uint32_t>(options, "pngCompressionLevel");
+  baton->pngAdaptiveFiltering = AttrTo<bool>(options, "pngAdaptiveFiltering");
+  baton->webpQuality = AttrTo<uint32_t>(options, "webpQuality");
+  baton->webpAlphaQuality = AttrTo<uint32_t>(options, "webpAlphaQuality");
+  baton->webpLossless = AttrTo<bool>(options, "webpLossless");
+  baton->webpNearLossless = AttrTo<bool>(options, "webpNearLossless");
+  baton->tiffQuality = AttrTo<uint32_t>(options, "tiffQuality");
   // Tile output
   baton->tileSize = AttrTo<uint32_t>(options, "tileSize");
   baton->tileOverlap = AttrTo<uint32_t>(options, "tileOverlap");
@@ -1155,6 +1216,7 @@ NAN_METHOD(pipeline) {
   } else {
     baton->tileLayout = VIPS_FOREIGN_DZ_LAYOUT_DZ;
   }
+  baton->tileFormat = AttrAsStr(options, "tileFormat");
 
   // Function to notify of queue length changes
   Nan::Callback *queueListener = new Nan::Callback(AttrAs<v8::Function>(options, "queueListener"));

src/pipeline.h

@@ -1,12 +1,28 @@
+// 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_PIPELINE_H_
 #define SRC_PIPELINE_H_
 
 #include <memory>
+#include <string>
+#include <vector>
 
+#include <nan.h>
 #include <vips/vips8>
 
-#include "nan.h"
-#include "common.h"
+#include "./common.h"
 
 NAN_METHOD(pipeline);
 
@@ -50,6 +66,7 @@ struct PipelineBaton {
   int cropCalcTop;
   std::string kernel;
   std::string interpolator;
+  bool centreSampling;
   double background[4];
   bool flatten;
   bool negate;
@@ -62,7 +79,7 @@ struct PipelineBaton {
   int trimTolerance;
   double gamma;
   bool greyscale;
-  bool normalize;
+  bool normalise;
   int angle;
   bool rotateBeforePreExtract;
   bool flip;
@@ -71,16 +88,22 @@ struct PipelineBaton {
   int extendBottom;
   int extendLeft;
   int extendRight;
-  bool progressive;
   bool withoutEnlargement;
   VipsAccess accessMethod;
-  int quality;
-  int compressionLevel;
-  bool withoutAdaptiveFiltering;
-  bool withoutChromaSubsampling;
-  bool trellisQuantisation;
-  bool overshootDeringing;
-  bool optimiseScans;
+  int jpegQuality;
+  bool jpegProgressive;
+  std::string jpegChromaSubsampling;
+  bool jpegTrellisQuantisation;
+  bool jpegOvershootDeringing;
+  bool jpegOptimiseScans;
+  bool pngProgressive;
+  int pngCompressionLevel;
+  bool pngAdaptiveFiltering;
+  int webpQuality;
+  int webpAlphaQuality;
+  bool webpNearLossless;
+  bool webpLossless;
+  int tiffQuality;
   std::string err;
   bool withMetadata;
   int withMetadataOrientation;
@@ -98,6 +121,7 @@ struct PipelineBaton {
   int tileOverlap;
   VipsForeignDzContainer tileContainer;
   VipsForeignDzLayout tileLayout;
+  std::string tileFormat;
 
   PipelineBaton():
     input(nullptr),
@@ -116,6 +140,7 @@ struct PipelineBaton {
     crop(0),
     cropCalcLeft(-1),
     cropCalcTop(-1),
+    centreSampling(false),
     flatten(false),
     negate(false),
     blurSigma(0.0),
@@ -127,7 +152,7 @@ struct PipelineBaton {
     trimTolerance(0),
     gamma(0.0),
     greyscale(false),
-    normalize(false),
+    normalise(false),
     angle(0),
     flip(false),
     flop(false),
@@ -135,15 +160,18 @@ struct PipelineBaton {
     extendBottom(0),
     extendLeft(0),
     extendRight(0),
-    progressive(false),
     withoutEnlargement(false),
-    quality(80),
-    compressionLevel(6),
-    withoutAdaptiveFiltering(false),
-    withoutChromaSubsampling(false),
-    trellisQuantisation(false),
-    overshootDeringing(false),
-    optimiseScans(false),
+    jpegQuality(80),
+    jpegProgressive(false),
+    jpegChromaSubsampling("4:2:0"),
+    jpegTrellisQuantisation(false),
+    jpegOvershootDeringing(false),
+    jpegOptimiseScans(false),
+    pngProgressive(false),
+    pngCompressionLevel(6),
+    pngAdaptiveFiltering(true),
+    webpQuality(80),
+    tiffQuality(80),
     withMetadata(false),
     withMetadataOrientation(-1),
     convKernelWidth(0),

src/sharp.cc

@@ -1,7 +1,20 @@
-#include <node.h>
-#include <vips/vips8>
+// 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 "nan.h"
+#include <node.h>
+#include <nan.h>
+#include <vips/vips8>
 
 #include "common.h"
 #include "metadata.h"

src/utilities.cc

@@ -1,10 +1,25 @@
+// 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 <cmath>
+#include <string>
+
 #include <node.h>
+#include <nan.h>
 #include <vips/vips8>
 #include <vips/vector.h>
 
-#include "nan.h"
-
 #include "common.h"
 #include "operations.h"
 #include "utilities.h"
@@ -45,14 +60,11 @@ NAN_METHOD(cache) {
   // Get memory stats
   Local<Object> memory = New<Object>();
   Set(memory, New("current").ToLocalChecked(),
-    New<Integer>(static_cast<int>(round(vips_tracked_get_mem() / 1048576)))
-  );
+    New<Integer>(static_cast<int>(round(vips_tracked_get_mem() / 1048576))));
   Set(memory, New("high").ToLocalChecked(),
-    New<Integer>(static_cast<int>(round(vips_tracked_get_mem_highwater() / 1048576)))
-  );
+    New<Integer>(static_cast<int>(round(vips_tracked_get_mem_highwater() / 1048576))));
   Set(memory, New("max").ToLocalChecked(),
-    New<Integer>(static_cast<int>(round(vips_cache_get_max_mem() / 1048576)))
-  );
+    New<Integer>(static_cast<int>(round(vips_cache_get_max_mem() / 1048576))));
   // Get file stats
   Local<Object> files = New<Object>();
   Set(files, New("current").ToLocalChecked(), New<Integer>(vips_tracked_get_files()));

src/utilities.h

@@ -1,7 +1,21 @@
+// 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_UTILITIES_H_
 #define SRC_UTILITIES_H_
 
-#include "nan.h"
+#include <nan.h>
 
 NAN_METHOD(cache);
 NAN_METHOD(concurrency);

test/bench/package.json

@@ -8,17 +8,18 @@
     "test": "VIPS_WARNING=0 node perf && node random && node parallel"
   },
   "devDependencies": {
-    "async": "^2.1.1",
-    "benchmark": "^2.1.1",
+    "async": "^2.1.4",
+    "benchmark": "^2.1.2",
     "gm": "^1.23.0",
     "imagemagick": "^0.1.3",
     "imagemagick-native": "^1.9.3",
     "jimp": "^0.2.27",
     "lwip": "^0.0.9",
+    "mapnik": "^3.5.14",
     "semver": "^5.3.0"
   },
   "license": "Apache-2.0",
   "engines": {
-    "node": ">=0.10"
+    "node": ">=4"
   }
 }

test/bench/parallel.js

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

test/bench/perf.js

@@ -1,34 +1,34 @@
 'use strict';
 
-var fs = require('fs');
+const fs = require('fs');
 
-var async = require('async');
-var assert = require('assert');
-var Benchmark = require('benchmark');
-var semver = require('semver');
+const async = require('async');
+const assert = require('assert');
+const Benchmark = require('benchmark');
 
 // Contenders
-var gm = require('gm');
-var imagemagick = require('imagemagick');
-var jimp = require('jimp');
-var sharp = require('../../');
-var imagemagickNative;
+const gm = require('gm');
+const imagemagick = require('imagemagick');
+const mapnik = require('mapnik');
+const jimp = require('jimp');
+const sharp = require('../../');
+let imagemagickNative;
 try {
   imagemagickNative = require('imagemagick-native');
 } catch (err) {
   console.log('Excluding imagemagick-native');
 }
-var lwip;
+let lwip;
 try {
   lwip = require('lwip');
 } catch (err) {
   console.log('Excluding lwip');
 }
 
-var fixtures = require('../fixtures');
+const fixtures = require('../fixtures');
 
-var width = 720;
-var height = 480;
+const width = 720;
+const height = 588;
 
 // Disable libvips cache to ensure tests are as fair as they can be
 sharp.cache(false);
@@ -36,18 +36,18 @@ sharp.cache(false);
 sharp.simd(true);
 
 async.series({
-  'jpeg': function(callback) {
-    var inputJpgBuffer = fs.readFileSync(fixtures.inputJpg);
-    var jpegSuite = new Benchmark.Suite('jpeg');
+  'jpeg': function (callback) {
+    const inputJpgBuffer = fs.readFileSync(fixtures.inputJpg);
+    const jpegSuite = new Benchmark.Suite('jpeg');
     // jimp
     jpegSuite.add('jimp-buffer-buffer', {
       defer: true,
-      fn: function(deferred) {
-        new jimp(inputJpgBuffer, function(err) {
+      fn: function (deferred) {
+        jimp.read(inputJpgBuffer, function (err, image) {
           if (err) {
             throw err;
           } else {
-            this
+            image
               .resize(width, height)
               .quality(80)
               .getBuffer(jimp.MIME_JPEG, function (err) {
@@ -62,12 +62,12 @@ async.series({
       }
     }).add('jimp-file-file', {
       defer: true,
-      fn: function(deferred) {
-        new jimp(fixtures.inputJpg, function(err) {
+      fn: function (deferred) {
+        jimp.read(fixtures.inputJpg, function (err, image) {
           if (err) {
             throw err;
           } else {
-            this
+            image
               .resize(width, height)
               .quality(80)
               .write(fixtures.outputJpg, function (err) {
@@ -85,7 +85,7 @@ async.series({
     if (typeof lwip !== 'undefined') {
       jpegSuite.add('lwip-file-file', {
         defer: true,
-        fn: function(deferred) {
+        fn: function (deferred) {
           lwip.open(fixtures.inputJpg, function (err, image) {
             if (err) {
               throw err;
@@ -105,7 +105,7 @@ async.series({
         }
       }).add('lwip-buffer-buffer', {
         defer: true,
-        fn: function(deferred) {
+        fn: function (deferred) {
           lwip.open(inputJpgBuffer, 'jpg', function (err, image) {
             if (err) {
               throw err;
@@ -126,10 +126,42 @@ async.series({
         }
       });
     }
+    // mapnik
+    jpegSuite.add('mapnik-file-file', {
+      defer: true,
+      fn: function (deferred) {
+        mapnik.Image.open(fixtures.inputJpg, function (err, img) {
+          if (err) throw err;
+          img
+            .resize(width, height, {
+              scaling_method: mapnik.imageScaling.lanczos
+            })
+            .save(fixtures.outputJpg, 'jpeg:quality=80', function (err) {
+              if (err) throw err;
+              deferred.resolve();
+            });
+        });
+      }
+    }).add('mapnik-buffer-buffer', {
+      defer: true,
+      fn: function (deferred) {
+        mapnik.Image.fromBytes(inputJpgBuffer, function (err, img) {
+          if (err) throw err;
+          img
+            .resize(width, height, {
+              scaling_method: mapnik.imageScaling.lanczos
+            })
+            .encode('jpeg:quality=80', function (err) {
+              if (err) throw err;
+              deferred.resolve();
+            });
+        });
+      }
+    });
     // imagemagick
     jpegSuite.add('imagemagick-file-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         imagemagick.resize({
           srcPath: fixtures.inputJpg,
           dstPath: fixtures.outputJpg,
@@ -138,7 +170,7 @@ async.series({
           height: height,
           format: 'jpg',
           filter: 'Lanczos'
-        }, function(err) {
+        }, function (err) {
           if (err) {
             throw err;
           } else {
@@ -151,7 +183,7 @@ async.series({
     if (typeof imagemagickNative !== 'undefined') {
       jpegSuite.add('imagemagick-native-buffer-buffer', {
         defer: true,
-        fn: function(deferred) {
+        fn: function (deferred) {
           imagemagickNative.convert({
             srcData: inputJpgBuffer,
             quality: 80,
@@ -173,10 +205,10 @@ async.series({
     // gm
     jpegSuite.add('gm-buffer-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         gm(inputJpgBuffer)
-          .resize(width, height)
           .filter('Lanczos')
+          .resize(width, height)
           .quality(80)
           .write(fixtures.outputJpg, function (err) {
             if (err) {
@@ -188,10 +220,10 @@ async.series({
       }
     }).add('gm-buffer-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         gm(inputJpgBuffer)
-          .resize(width, height)
           .filter('Lanczos')
+          .resize(width, height)
           .quality(80)
           .toBuffer(function (err, buffer) {
             if (err) {
@@ -204,10 +236,10 @@ async.series({
       }
     }).add('gm-file-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         gm(fixtures.inputJpg)
-          .resize(width, height)
           .filter('Lanczos')
+          .resize(width, height)
           .quality(80)
           .write(fixtures.outputJpg, function (err) {
             if (err) {
@@ -219,10 +251,10 @@ async.series({
       }
     }).add('gm-file-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         gm(fixtures.inputJpg)
-          .resize(width, height)
           .filter('Lanczos')
+          .resize(width, height)
           .quality(80)
           .toBuffer(function (err, buffer) {
             if (err) {
@@ -237,10 +269,10 @@ async.series({
     // sharp
     jpegSuite.add('sharp-buffer-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
-          .toFile(fixtures.outputJpg, function(err) {
+          .toFile(fixtures.outputJpg, function (err) {
             if (err) {
               throw err;
             } else {
@@ -250,10 +282,10 @@ async.series({
       }
     }).add('sharp-buffer-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -264,10 +296,10 @@ async.series({
       }
     }).add('sharp-file-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(fixtures.inputJpg)
           .resize(width, height)
-          .toFile(fixtures.outputJpg, function(err) {
+          .toFile(fixtures.outputJpg, function (err) {
             if (err) {
               throw err;
             } else {
@@ -277,22 +309,22 @@ async.series({
       }
     }).add('sharp-stream-stream', {
       defer: true,
-      fn: function(deferred) {
-        var readable = fs.createReadStream(fixtures.inputJpg);
-        var writable = fs.createWriteStream(fixtures.outputJpg);
-        writable.on('finish', function() {
+      fn: function (deferred) {
+        const readable = fs.createReadStream(fixtures.inputJpg);
+        const writable = fs.createWriteStream(fixtures.outputJpg);
+        writable.on('finish', function () {
           deferred.resolve();
         });
-        var pipeline = sharp()
+        const pipeline = sharp()
           .resize(width, height);
         readable.pipe(pipeline).pipe(writable);
       }
     }).add('sharp-file-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(fixtures.inputJpg)
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -303,32 +335,32 @@ async.series({
       }
     }).add('sharp-promise', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .toBuffer()
-          .then(function(buffer) {
+          .then(function (buffer) {
             assert.notStrictEqual(null, buffer);
             deferred.resolve();
           });
       }
-    }).on('cycle', function(event) {
+    }).on('cycle', function (event) {
       console.log('jpeg ' + String(event.target));
-    }).on('complete', function() {
+    }).on('complete', function () {
       callback(null, this.filter('fastest').map('name'));
     }).run();
   },
   // Effect of applying operations
-  operations: function(callback) {
-    var inputJpgBuffer = fs.readFileSync(fixtures.inputJpg);
-    var operationsSuite = new Benchmark.Suite('operations');
+  operations: function (callback) {
+    const inputJpgBuffer = fs.readFileSync(fixtures.inputJpg);
+    const operationsSuite = new Benchmark.Suite('operations');
     operationsSuite.add('sharp-sharpen-mild', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .sharpen()
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -339,11 +371,11 @@ async.series({
       }
     }).add('sharp-sharpen-radius', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .sharpen(3, 1, 3)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -354,11 +386,11 @@ async.series({
       }
     }).add('sharp-blur-mild', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .blur()
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -369,11 +401,11 @@ async.series({
       }
     }).add('sharp-blur-radius', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .blur(3)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -384,11 +416,11 @@ async.series({
       }
     }).add('sharp-gamma', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .gamma()
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -399,11 +431,11 @@ async.series({
       }
     }).add('sharp-normalise', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .normalise()
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -414,11 +446,11 @@ async.series({
       }
     }).add('sharp-greyscale', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .greyscale()
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -429,12 +461,12 @@ async.series({
       }
     }).add('sharp-greyscale-gamma', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .gamma()
           .greyscale()
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -445,11 +477,11 @@ async.series({
       }
     }).add('sharp-progressive', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
-          .progressive()
-          .toBuffer(function(err, buffer) {
+          .jpeg({ progressive: true })
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -460,11 +492,11 @@ async.series({
       }
     }).add('sharp-without-chroma-subsampling', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
-          .withoutChromaSubsampling()
-          .toBuffer(function(err, buffer) {
+          .jpeg({ chromaSubsampling: '4:4:4' })
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -475,11 +507,11 @@ async.series({
       }
     }).add('sharp-rotate', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .rotate(90)
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -490,11 +522,11 @@ async.series({
       }
     }).add('sharp-without-simd', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp.simd(false);
         sharp(inputJpgBuffer)
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             sharp.simd(true);
             if (err) {
               throw err;
@@ -506,11 +538,11 @@ async.series({
       }
     }).add('sharp-sequentialRead', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .sequentialRead()
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -521,11 +553,11 @@ async.series({
       }
     }).add('sharp-crop-entropy', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .crop(sharp.strategy.entropy)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -536,11 +568,11 @@ async.series({
       }
     }).add('sharp-crop-attention', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height)
           .crop(sharp.strategy.attention)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -549,21 +581,21 @@ async.series({
             }
           });
       }
-    }).on('cycle', function(event) {
+    }).on('cycle', function (event) {
       console.log('operations ' + String(event.target));
-    }).on('complete', function() {
+    }).on('complete', function () {
       callback(null, this.filter('fastest').map('name'));
     }).run();
   },
   // Comparitive speed of kernels
-  kernels: function(callback) {
-    var inputJpgBuffer = fs.readFileSync(fixtures.inputJpg);
+  kernels: function (callback) {
+    const inputJpgBuffer = fs.readFileSync(fixtures.inputJpg);
     (new Benchmark.Suite('kernels')).add('sharp-cubic', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height, { kernel: 'cubic' })
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -574,10 +606,10 @@ async.series({
       }
     }).add('sharp-lanczos2', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height, { kernel: 'lanczos2' })
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -588,10 +620,10 @@ async.series({
       }
     }).add('sharp-lanczos3', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputJpgBuffer)
           .resize(width, height, { kernel: 'lanczos3' })
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -600,25 +632,25 @@ async.series({
             }
           });
       }
-    }).on('cycle', function(event) {
+    }).on('cycle', function (event) {
       console.log('kernels ' + String(event.target));
-    }).on('complete', function() {
+    }).on('complete', function () {
       callback(null, this.filter('fastest').map('name'));
     }).run();
   },
   // PNG
-  png: function(callback) {
-    var inputPngBuffer = fs.readFileSync(fixtures.inputPng);
-    var pngSuite = new Benchmark.Suite('png');
+  png: function (callback) {
+    const inputPngBuffer = fs.readFileSync(fixtures.inputPng);
+    const pngSuite = new Benchmark.Suite('png');
     // jimp
     pngSuite.add('jimp-buffer-buffer', {
       defer: true,
-      fn: function(deferred) {
-        new jimp(inputPngBuffer, function(err) {
+      fn: function (deferred) {
+        jimp.read(inputPngBuffer, function (err, image) {
           if (err) {
             throw err;
           } else {
-            this
+            image
               .resize(width, height)
               .getBuffer(jimp.MIME_PNG, function (err) {
                 if (err) {
@@ -632,12 +664,12 @@ async.series({
       }
     }).add('jimp-file-file', {
       defer: true,
-      fn: function(deferred) {
-        new jimp(fixtures.inputPng, function(err) {
+      fn: function (deferred) {
+        jimp.read(fixtures.inputPng, function (err, image) {
           if (err) {
             throw err;
           } else {
-            this
+            image
               .resize(width, height)
               .write(fixtures.outputPng, function (err) {
                 if (err) {
@@ -654,7 +686,7 @@ async.series({
     if (typeof lwip !== 'undefined') {
       pngSuite.add('lwip-buffer-buffer', {
         defer: true,
-        fn: function(deferred) {
+        fn: function (deferred) {
           lwip.open(inputPngBuffer, 'png', function (err, image) {
             if (err) {
               throw err;
@@ -675,17 +707,63 @@ async.series({
         }
       });
     }
+    // mapnik
+    pngSuite.add('mapnik-file-file', {
+      defer: true,
+      fn: function (deferred) {
+        mapnik.Image.open(fixtures.inputPng, function (err, img) {
+          if (err) throw err;
+          img.premultiply(function (err, img) {
+            if (err) throw err;
+            img.resize(width, height, {
+              scaling_method: mapnik.imageScaling.lanczos
+            }, function (err, img) {
+              if (err) throw err;
+              img.demultiply(function (err, img) {
+                if (err) throw err;
+                img.save(fixtures.outputPng, 'png', function (err) {
+                  if (err) throw err;
+                  deferred.resolve();
+                });
+              });
+            });
+          });
+        });
+      }
+    }).add('mapnik-buffer-buffer', {
+      defer: true,
+      fn: function (deferred) {
+        mapnik.Image.fromBytes(inputPngBuffer, function (err, img) {
+          if (err) throw err;
+          img.premultiply(function (err, img) {
+            if (err) throw err;
+            img.resize(width, height, {
+              scaling_method: mapnik.imageScaling.lanczos
+            }, function (err, img) {
+              if (err) throw err;
+              img.demultiply(function (err, img) {
+                if (err) throw err;
+                img.encode('png', function (err) {
+                  if (err) throw err;
+                  deferred.resolve();
+                });
+              });
+            });
+          });
+        });
+      }
+    });
     // imagemagick
     pngSuite.add('imagemagick-file-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         imagemagick.resize({
           srcPath: fixtures.inputPng,
           dstPath: fixtures.outputPng,
           width: width,
           height: height,
           filter: 'Lanczos'
-        }, function(err) {
+        }, function (err) {
           if (err) {
             throw err;
           } else {
@@ -698,7 +776,7 @@ async.series({
     if (typeof imagemagickNative !== 'undefined') {
       pngSuite.add('imagemagick-native-buffer-buffer', {
         defer: true,
-        fn: function(deferred) {
+        fn: function (deferred) {
           imagemagickNative.convert({
             srcData: inputPngBuffer,
             width: width,
@@ -713,10 +791,10 @@ async.series({
     // gm
     pngSuite.add('gm-file-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         gm(fixtures.inputPng)
-          .resize(width, height)
           .filter('Lanczos')
+          .resize(width, height)
           .write(fixtures.outputPng, function (err) {
             if (err) {
               throw err;
@@ -727,10 +805,10 @@ async.series({
       }
     }).add('gm-file-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         gm(fixtures.inputPng)
-          .resize(width, height)
           .filter('Lanczos')
+          .resize(width, height)
           .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
@@ -744,10 +822,10 @@ async.series({
     // sharp
     pngSuite.add('sharp-buffer-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputPngBuffer)
           .resize(width, height)
-          .toFile(fixtures.outputPng, function(err) {
+          .toFile(fixtures.outputPng, function (err) {
             if (err) {
               throw err;
             } else {
@@ -757,10 +835,10 @@ async.series({
       }
     }).add('sharp-buffer-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputPngBuffer)
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -771,10 +849,10 @@ async.series({
       }
     }).add('sharp-file-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(fixtures.inputPng)
           .resize(width, height)
-          .toFile(fixtures.outputPng, function(err) {
+          .toFile(fixtures.outputPng, function (err) {
             if (err) {
               throw err;
             } else {
@@ -784,10 +862,10 @@ async.series({
       }
     }).add('sharp-file-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(fixtures.inputPng)
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -798,11 +876,11 @@ async.series({
       }
     }).add('sharp-progressive', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputPngBuffer)
           .resize(width, height)
-          .progressive()
-          .toBuffer(function(err, buffer) {
+          .png({ progressive: true })
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -813,11 +891,11 @@ async.series({
       }
     }).add('sharp-withoutAdaptiveFiltering', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputPngBuffer)
           .resize(width, height)
-          .withoutAdaptiveFiltering()
-          .toBuffer(function(err, buffer) {
+          .png({ adaptiveFiltering: false })
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -827,21 +905,21 @@ async.series({
           });
       }
     });
-    pngSuite.on('cycle', function(event) {
+    pngSuite.on('cycle', function (event) {
       console.log(' png ' + String(event.target));
-    }).on('complete', function() {
+    }).on('complete', function () {
       callback(null, this.filter('fastest').map('name'));
     }).run();
   },
   // WebP
-  webp: function(callback) {
-    var inputWebPBuffer = fs.readFileSync(fixtures.inputWebP);
+  webp: function (callback) {
+    const inputWebPBuffer = fs.readFileSync(fixtures.inputWebP);
     (new Benchmark.Suite('webp')).add('sharp-buffer-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputWebPBuffer)
           .resize(width, height)
-          .toFile(fixtures.outputWebP, function(err) {
+          .toFile(fixtures.outputWebP, function (err) {
             if (err) {
               throw err;
             } else {
@@ -851,10 +929,10 @@ async.series({
       }
     }).add('sharp-buffer-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(inputWebPBuffer)
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -865,10 +943,10 @@ async.series({
       }
     }).add('sharp-file-file', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(fixtures.inputWebP)
           .resize(width, height)
-          .toFile(fixtures.outputWebP, function(err) {
+          .toFile(fixtures.outputWebP, function (err) {
             if (err) {
               throw err;
             } else {
@@ -878,10 +956,10 @@ async.series({
       }
     }).add('sharp-file-buffer', {
       defer: true,
-      fn: function(deferred) {
+      fn: function (deferred) {
         sharp(fixtures.inputWebp)
           .resize(width, height)
-          .toBuffer(function(err, buffer) {
+          .toBuffer(function (err, buffer) {
             if (err) {
               throw err;
             } else {
@@ -890,15 +968,15 @@ async.series({
             }
           });
       }
-    }).on('cycle', function(event) {
+    }).on('cycle', function (event) {
       console.log('webp ' + String(event.target));
-    }).on('complete', function() {
+    }).on('complete', function () {
       callback(null, this.filter('fastest').map('name'));
     }).run();
   }
-}, function(err, results) {
+}, function (err, results) {
   assert(!err, err);
-  Object.keys(results).forEach(function(format) {
+  Object.keys(results).forEach(function (format) {
     if (results[format].toString().substr(0, 5) !== 'sharp') {
       console.log('sharp was slower than ' + results[format] + ' for ' + format);
     }

test/bench/random.js

@@ -1,26 +1,26 @@
 'use strict';
 
-var imagemagick = require('imagemagick');
-var gm = require('gm');
-var assert = require('assert');
-var Benchmark = require('benchmark');
+const imagemagick = require('imagemagick');
+const gm = require('gm');
+const assert = require('assert');
+const Benchmark = require('benchmark');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
 sharp.cache(false);
 sharp.simd(true);
 
-var min = 320;
-var max = 960;
+const min = 320;
+const max = 960;
 
-var randomDimension = function() {
+const randomDimension = function () {
   return Math.ceil(Math.random() * (max - min) + min);
 };
 
 new Benchmark.Suite('random').add('imagemagick', {
   defer: true,
-  fn: function(deferred) {
+  fn: function (deferred) {
     imagemagick.resize({
       srcPath: fixtures.inputJpg,
       dstPath: fixtures.outputJpg,
@@ -29,7 +29,7 @@ new Benchmark.Suite('random').add('imagemagick', {
       height: randomDimension(),
       format: 'jpg',
       filter: 'Lanczos'
-    }, function(err) {
+    }, function (err) {
       if (err) {
         throw err;
       } else {
@@ -39,7 +39,7 @@ new Benchmark.Suite('random').add('imagemagick', {
   }
 }).add('gm', {
   defer: true,
-  fn: function(deferred) {
+  fn: function (deferred) {
     gm(fixtures.inputJpg)
       .resize(randomDimension(), randomDimension())
       .filter('Lanczos')
@@ -55,10 +55,10 @@ new Benchmark.Suite('random').add('imagemagick', {
   }
 }).add('sharp', {
   defer: true,
-  fn: function(deferred) {
+  fn: function (deferred) {
     sharp(fixtures.inputJpg)
       .resize(randomDimension(), randomDimension())
-      .toBuffer(function(err, buffer) {
+      .toBuffer(function (err, buffer) {
         if (err) {
           throw err;
         } else {
@@ -67,9 +67,9 @@ new Benchmark.Suite('random').add('imagemagick', {
         }
       });
   }
-}).on('cycle', function(event) {
+}).on('cycle', function (event) {
   console.log(String(event.target));
-}).on('complete', function() {
-  var winner = this.filter('fastest').map('name');
+}).on('complete', function () {
+  const winner = this.filter('fastest').map('name');
   assert.strictEqual('sharp', String(winner), 'sharp was slower than ' + winner);
 }).run();

test/fixtures/index.js

@@ -1,34 +1,32 @@
 'use strict';
 
-var path = require('path');
-var assert = require('assert');
-var sharp = require('../../index');
-var maxColourDistance = require('../../build/Release/sharp')._maxColourDistance;
+const path = require('path');
+const sharp = require('../../');
+const maxColourDistance = require('../../build/Release/sharp')._maxColourDistance;
 
 // Helpers
-var getPath = function(filename) {
+const getPath = function (filename) {
   return path.join(__dirname, filename);
 };
 
 // Generates a 64-bit-as-binary-string image fingerprint
 // Based on the dHash gradient method - see http://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html
-var fingerprint = function(image, callback) {
+const fingerprint = function (image, callback) {
   sharp(image)
     .greyscale()
     .normalise()
     .resize(9, 8)
     .ignoreAspectRatio()
     .raw()
-    .toBuffer(function(err, data) {
+    .toBuffer(function (err, data) {
       if (err) {
         callback(err);
       } else {
-        var fingerprint = '';
-        for (var col = 0; col < 8; col++) {
-          var gradient = 0;
-          for (var row = 0; row < 8; row++) {
-            var left = data[row * 8 + col];
-            var right = data[row * 8 + col + 1];
+        let fingerprint = '';
+        for (let col = 0; col < 8; col++) {
+          for (let row = 0; row < 8; row++) {
+            const left = data[row * 8 + col];
+            const right = data[row * 8 + col + 1];
             fingerprint = fingerprint + (left < right ? '1' : '0');
           }
         }
@@ -85,11 +83,11 @@ module.exports = {
   inputWebP: getPath('4.webp'), // http://www.gstatic.com/webp/gallery/4.webp
   inputWebPWithTransparency: getPath('5_webp_a.webp'), // http://www.gstatic.com/webp/gallery3/5_webp_a.webp
   inputTiff: getPath('G31D.TIF'), // http://www.fileformat.info/format/tiff/sample/e6c9a6e5253348f4aef6d17b534360ab/index.htm
+  inputTiffCielab: getPath('cielab-dagams.tiff'), // https://github.com/lovell/sharp/issues/646
   inputGif: getPath('Crash_test.gif'), // http://upload.wikimedia.org/wikipedia/commons/e/e3/Crash_test.gif
   inputGifGreyPlusAlpha: getPath('grey-plus-alpha.gif'), // http://i.imgur.com/gZ5jlmE.gif
   inputSvg: getPath('check.svg'), // http://dev.w3.org/SVG/tools/svgweb/samples/svg-files/check.svg
-
-  inputSvs: getPath('CMU-1-Small-Region.svs'), // http://openslide.cs.cmu.edu/download/openslide-testdata/Aperio/CMU-1-Small-Region.svs
+  inputSvgWithEmbeddedImages: getPath('struct-image-04-t.svg'), // https://dev.w3.org/SVG/profiles/1.2T/test/svg/struct-image-04-t.svg
 
   inputJPGBig: getPath('flowers.jpeg'),
 
@@ -110,14 +108,14 @@ module.exports = {
   path: getPath,
 
   // Path for expected output images
-  expected: function(filename) {
+  expected: function (filename) {
     return getPath(path.join('expected', filename));
   },
 
   // Verify similarity of expected vs actual images via fingerprint
   // Specify distance threshold using `options={threshold: 42}`, default
   // `threshold` is 5;
-  assertSimilar: function(expectedImage, actualImage, options, callback) {
+  assertSimilar: function (expectedImage, actualImage, options, callback) {
     if (typeof options === 'function') {
       callback = options;
       options = {};
@@ -139,12 +137,12 @@ module.exports = {
       throw new TypeError('`callback` must be a function');
     }
 
-    fingerprint(expectedImage, function(err, expectedFingerprint) {
+    fingerprint(expectedImage, function (err, expectedFingerprint) {
       if (err) return callback(err);
-      fingerprint(actualImage, function(err, actualFingerprint) {
+      fingerprint(actualImage, function (err, actualFingerprint) {
         if (err) return callback(err);
-        var distance = 0;
-        for (var i = 0; i < 64; i++) {
+        let distance = 0;
+        for (let i = 0; i < 64; i++) {
           if (expectedFingerprint[i] !== actualFingerprint[i]) {
             distance++;
           }
@@ -159,7 +157,7 @@ module.exports = {
     });
   },
 
-  assertMaxColourDistance: function(actualImagePath, expectedImagePath, acceptedDistance) {
+  assertMaxColourDistance: function (actualImagePath, expectedImagePath, acceptedDistance) {
     if (typeof actualImagePath !== 'string') {
       throw new TypeError('`actualImagePath` must be a string; got ' + actualImagePath);
     }
@@ -170,7 +168,7 @@ module.exports = {
       // Default threshold
       acceptedDistance = 1;
     }
-    var distance = maxColourDistance(actualImagePath, expectedImagePath);
+    const distance = maxColourDistance(actualImagePath, expectedImagePath);
     if (distance > acceptedDistance) {
       throw new Error('Expected maximum absolute distance of ' + acceptedDistance + ', actual ' + distance);
     }

test/leak/sharp.supp

@@ -277,6 +277,17 @@
   ...
   fun:_ZN6icu_568Collator19getAvailableLocalesERi
 }
+{
+  leak_nodejs_thread_start
+  Memcheck:Leak
+  match-leak-kinds: possible
+  fun:calloc
+  fun:allocate_dtv
+  fun:_dl_allocate_tls
+  fun:allocate_stack
+  ...
+  fun:_ZN2v84base6Thread5StartEv
+}
 {
   leak_nan_FunctionCallbackInfo
   Memcheck:Leak

test/saliency/humanae/download.js

@@ -1,5 +1,4 @@
 'use strict';
-/*jshint esversion: 6 */
 
 const fs = require('fs');
 const request = require('request');
@@ -10,7 +9,7 @@ const client = tumblr.createClient({
   consumer_secret: '***'
 });
 
-const fetchImages = function(offset) {
+const fetchImages = function (offset) {
   console.log(`Fetching offset ${offset}`);
   client.posts('humanae', {
     type: 'photo',
@@ -21,8 +20,7 @@ const fetchImages = function(offset) {
       response.posts.forEach((post) => {
         const url = post.photos[0].alt_sizes
           .filter((image) => image.width === 100)
-          .map((image) => image.url)
-          [0];
+          .map((image) => image.url)[0];
         const filename = `./images/${post.id}.jpg`;
         try {
           fs.statSync(filename);

test/saliency/humanae/tone.js

@@ -1,8 +1,7 @@
 'use strict';
-/*jshint esversion: 6 */
 
 const fs = require('fs');
-const child_process = require('child_process');
+const childProcess = require('child_process');
 
 const a = [];
 const b = [];
@@ -12,7 +11,7 @@ fs.readdirSync('./images')
   .forEach((file) => {
     // Extract one pixel, avoiding first DCT block, and return value of A and B channels
     const command = `convert ./images/${file}[1x1+8+8] -colorspace lab -format "%[fx:u.g] %[fx:u.b]" info:`;
-    const result = child_process.execSync(command, { encoding: 'utf8' });
+    const result = childProcess.execSync(command, { encoding: 'utf8' });
     const ab = result.split(' ');
     a.push(ab[0]);
     b.push(ab[1]);
@@ -22,7 +21,7 @@ a.sort((v1, v2) => v1 - v2);
 b.sort((v1, v2) => v1 - v2);
 
 // Convert from 0..1 to -128..128
-const convert = function(v) {
+const convert = function (v) {
   return Math.round(256 * (v - 0.5));
 };
 

test/saliency/report.js

@@ -1,5 +1,4 @@
 'use strict';
-/*jshint esversion: 6 */
 
 const os = require('os');
 const fs = require('fs');
@@ -16,7 +15,7 @@ const concurrency = os.cpus().length;
 
 const scores = {};
 
-const incrementScore = function(accuracy, crop) {
+const incrementScore = function (accuracy, crop) {
   if (typeof scores[accuracy] === 'undefined') {
     scores[accuracy] = {};
   }
@@ -29,36 +28,36 @@ const incrementScore = function(accuracy, crop) {
 const userData = require('./userData.json');
 const files = Object.keys(userData);
 
-async.eachLimit(files, concurrency, function(file, done) {
+async.eachLimit(files, concurrency, function (file, done) {
   const filename = path.join(__dirname, 'Image', file);
   const salientWidth = userData[file].right - userData[file].left;
   const salientHeight = userData[file].bottom - userData[file].top;
-  sharp(filename).metadata(function(err, metadata) {
+  sharp(filename).metadata(function (err, metadata) {
     if (err) console.log(err);
-    async.each(Object.keys(crops), function(crop, done) {
+    async.each(Object.keys(crops), function (crop, done) {
       async.parallel([
         // Left edge accuracy
-        function(done) {
-          sharp(filename).resize(salientWidth, metadata.height).crop(crops[crop]).toBuffer(function(err, data, info) {
+        function (done) {
+          sharp(filename).resize(salientWidth, metadata.height).crop(crops[crop]).toBuffer(function (err, data, info) {
             const accuracy = Math.round(Math.abs(userData[file].left - info.cropCalcLeft) / (metadata.width - salientWidth) * 100);
             incrementScore(accuracy, crop);
-            done();
+            done(err);
           });
         },
         // Top edge accuracy
-        function(done) {
-          sharp(filename).resize(metadata.width, salientHeight).crop(crops[crop]).toBuffer(function(err, data, info) {
+        function (done) {
+          sharp(filename).resize(metadata.width, salientHeight).crop(crops[crop]).toBuffer(function (err, data, info) {
             const accuracy = Math.round(Math.abs(userData[file].top - info.cropCalcTop) / (metadata.height - salientHeight) * 100);
             incrementScore(accuracy, crop);
-            done();
+            done(err);
           });
         }
       ], done);
     }, done);
   });
-}, function() {
+}, function () {
   const report = [];
-  Object.keys(scores).forEach(function(accuracy) {
+  Object.keys(scores).forEach(function (accuracy) {
     report.push(
       Object.assign({
         accuracy: parseInt(accuracy, 10)

test/saliency/userData.js

@@ -1,5 +1,4 @@
 'use strict';
-/*jshint esversion: 6, loopfunc: true */
 
 const fs = require('fs');
 const path = require('path');
@@ -8,8 +7,8 @@ const userDataDir = 'UserData';
 
 const images = {};
 
-const median = function(values) {
-  values.sort(function(a,b) {
+const median = function (values) {
+  values.sort(function (a, b) {
     return a - b;
   });
   const half = Math.floor(values.length / 2);
@@ -21,7 +20,7 @@ const median = function(values) {
 };
 
 // List of files
-fs.readdirSync(userDataDir).forEach(function(file) {
+fs.readdirSync(userDataDir).forEach(function (file) {
   // Contents of file
   const lines = fs.readFileSync(path.join(userDataDir, file), {encoding: 'utf-8'}).split(/\r\n/);
   // First line = number of entries
@@ -39,8 +38,11 @@ fs.readdirSync(userDataDir).forEach(function(file) {
     const regions = lines[linePos].split('; ');
     linePos = linePos + 2;
     // Parse human-labelled regions for min/max coords
-    const lefts = [], tops = [], rights = [], bottoms = [];
-    regions.forEach(function(region) {
+    const lefts = [];
+    const tops = [];
+    const rights = [];
+    const bottoms = [];
+    regions.forEach(function (region) {
       if (region.indexOf(' ') !== -1) {
         const coords = region.split(' ');
         lefts.push(parseInt(coords[0], 10));

test/unit/alpha.js

@@ -1,16 +1,15 @@
 'use strict';
 
-var assert = require('assert');
-var fixtures = require('../fixtures');
-var sharp = require('../../index');
+const assert = require('assert');
+const fixtures = require('../fixtures');
+const sharp = require('../../');
 
-describe('Alpha transparency', function() {
-
-  it('Flatten to black', function(done) {
+describe('Alpha transparency', function () {
+  it('Flatten to black', function (done) {
     sharp(fixtures.inputPngWithTransparency)
       .flatten()
       .resize(400, 300)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(400, info.width);
         assert.strictEqual(300, info.height);
@@ -18,12 +17,12 @@ describe('Alpha transparency', function() {
       });
   });
 
-  it('Flatten to RGB orange', function(done) {
+  it('Flatten to RGB orange', function (done) {
     sharp(fixtures.inputPngWithTransparency)
       .flatten()
       .background({r: 255, g: 102, b: 0})
       .resize(400, 300)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(400, info.width);
         assert.strictEqual(300, info.height);
@@ -31,12 +30,12 @@ describe('Alpha transparency', function() {
       });
   });
 
-  it('Flatten to CSS/hex orange', function(done) {
+  it('Flatten to CSS/hex orange', function (done) {
     sharp(fixtures.inputPngWithTransparency)
       .flatten()
       .background('#ff6600')
       .resize(400, 300)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(400, info.width);
         assert.strictEqual(300, info.height);
@@ -44,12 +43,12 @@ describe('Alpha transparency', function() {
       });
   });
 
-  it('Flatten 16-bit PNG with transparency to orange', function(done) {
-    var output = fixtures.path('output.flatten-rgb16-orange.jpg');
+  it('Flatten 16-bit PNG with transparency to orange', function (done) {
+    const output = fixtures.path('output.flatten-rgb16-orange.jpg');
     sharp(fixtures.inputPngWithTransparency16bit)
       .flatten()
       .background({r: 255, g: 102, b: 0})
-      .toFile(output, function(err, info) {
+      .toFile(output, function (err, info) {
         if (err) throw err;
         assert.strictEqual(true, info.size > 0);
         assert.strictEqual(32, info.width);
@@ -59,10 +58,10 @@ describe('Alpha transparency', function() {
       });
   });
 
-  it('Do not flatten', function(done) {
+  it('Do not flatten', function (done) {
     sharp(fixtures.inputPngWithTransparency)
       .flatten(false)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual('png', info.format);
         assert.strictEqual(4, info.channels);
@@ -70,11 +69,11 @@ describe('Alpha transparency', function() {
       });
   });
 
-  it('Ignored for JPEG', function(done) {
+  it('Ignored for JPEG', function (done) {
     sharp(fixtures.inputJpg)
       .background('#ff0000')
       .flatten()
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(3, info.channels);
@@ -82,13 +81,13 @@ describe('Alpha transparency', function() {
       });
   });
 
-  it('Enlargement with non-nearest neighbor interpolation shouldn’t cause dark edges', function(done) {
-    var BASE_NAME = 'alpha-premultiply-enlargement-2048x1536-paper.png';
-    var actual = fixtures.path('output.' + BASE_NAME);
-    var expected = fixtures.expected(BASE_NAME);
+  it('Enlargement with non-nearest neighbor interpolation shouldn’t cause dark edges', function (done) {
+    const base = 'alpha-premultiply-enlargement-2048x1536-paper.png';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
     sharp(fixtures.inputPngAlphaPremultiplicationSmall)
       .resize(2048, 1536)
-      .toFile(actual, function(err) {
+      .toFile(actual, function (err) {
         if (err) {
           done(err);
         } else {
@@ -98,13 +97,13 @@ describe('Alpha transparency', function() {
       });
   });
 
-  it('Reduction with non-nearest neighbor interpolation shouldn’t cause dark edges', function(done) {
-    var BASE_NAME = 'alpha-premultiply-reduction-1024x768-paper.png';
-    var actual = fixtures.path('output.' + BASE_NAME);
-    var expected = fixtures.expected(BASE_NAME);
+  it('Reduction with non-nearest neighbor interpolation shouldn’t cause dark edges', function (done) {
+    const base = 'alpha-premultiply-reduction-1024x768-paper.png';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
     sharp(fixtures.inputPngAlphaPremultiplicationLarge)
       .resize(1024, 768)
-      .toFile(actual, function(err) {
+      .toFile(actual, function (err) {
         if (err) {
           done(err);
         } else {
@@ -113,5 +112,4 @@ describe('Alpha transparency', function() {
         }
       });
   });
-
 });

test/unit/bandbool.js

@@ -1,22 +1,21 @@
 'use strict';
 
-var assert = require('assert');
-var fixtures = require('../fixtures');
-var sharp = require('../../index');
-
-describe('Bandbool per-channel boolean operations', function() {
+const assert = require('assert');
+const fixtures = require('../fixtures');
+const sharp = require('../../');
 
+describe('Bandbool per-channel boolean operations', function () {
   [
     sharp.bool.and,
     sharp.bool.or,
     sharp.bool.eor
   ]
-  .forEach(function(op) {
-    it(op + ' operation', function(done) {
+  .forEach(function (op) {
+    it(op + ' operation', function (done) {
       sharp(fixtures.inputPngBooleanNoAlpha)
         .bandbool(op)
         .toColourspace('b-w')
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual(200, info.width);
           assert.strictEqual(200, info.height);
@@ -26,23 +25,24 @@ describe('Bandbool per-channel boolean operations', function() {
     });
   });
 
-  it('sRGB image retains 3 channels', function(done) {
+  it('sRGB image retains 3 channels', function (done) {
     sharp(fixtures.inputJpg)
       .bandbool('and')
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
         assert.strictEqual(3, info.channels);
         done();
       });
-  });          
+  });
 
-  it('Invalid operation', function() {
-    assert.throws(function() {
+  it('Invalid operation', function () {
+    assert.throws(function () {
       sharp().bandbool('fail');
     });
   });
 
-  it('Missing operation', function() {
-    assert.throws(function() {
+  it('Missing operation', function () {
+    assert.throws(function () {
       sharp().bandbool();
     });
   });

test/unit/blur.js

@@ -1,17 +1,17 @@
 'use strict';
 
-var assert = require('assert');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
-describe('Blur', function() {
-
-  it('specific radius 1', function(done) {
+describe('Blur', function () {
+  it('specific radius 1', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .blur(1)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);
@@ -19,11 +19,12 @@ describe('Blur', function() {
       });
   });
 
-  it('specific radius 10', function(done) {
+  it('specific radius 10', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .blur(10)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);
@@ -31,11 +32,12 @@ describe('Blur', function() {
       });
   });
 
-  it('specific radius 0.3', function(done) {
+  it('specific radius 0.3', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .blur(0.3)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);
@@ -43,11 +45,12 @@ describe('Blur', function() {
       });
   });
 
-  it('mild blur', function(done) {
+  it('mild blur', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .blur()
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);
@@ -55,17 +58,18 @@ describe('Blur', function() {
       });
   });
 
-  it('invalid radius', function() {
-    assert.throws(function() {
+  it('invalid radius', function () {
+    assert.throws(function () {
       sharp(fixtures.inputJpg).blur(0.1);
     });
   });
 
-  it('blurred image is smaller than non-blurred', function(done) {
+  it('blurred image is smaller than non-blurred', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .blur(false)
-      .toBuffer(function(err, notBlurred, info) {
+      .toBuffer(function (err, notBlurred, info) {
+        if (err) throw err;
         assert.strictEqual(true, notBlurred.length > 0);
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(320, info.width);
@@ -73,7 +77,8 @@ describe('Blur', function() {
         sharp(fixtures.inputJpg)
           .resize(320, 240)
           .blur(true)
-          .toBuffer(function(err, blurred, info) {
+          .toBuffer(function (err, blurred, info) {
+            if (err) throw err;
             assert.strictEqual(true, blurred.length > 0);
             assert.strictEqual(true, blurred.length < notBlurred.length);
             assert.strictEqual('jpeg', info.format);
@@ -83,5 +88,4 @@ describe('Blur', function() {
           });
       });
   });
-
 });

test/unit/boolean.js

@@ -1,26 +1,25 @@
 'use strict';
 
-var fs = require('fs');
-var assert = require('assert');
-var fixtures = require('../fixtures');
-var sharp = require('../../index');
+const fs = require('fs');
+const assert = require('assert');
 
-describe('Boolean operation between two images', function() {
+const fixtures = require('../fixtures');
+const sharp = require('../../');
 
-  var inputJpgBooleanTestBuffer = fs.readFileSync(fixtures.inputJpgBooleanTest);
+describe('Boolean operation between two images', function () {
+  const inputJpgBooleanTestBuffer = fs.readFileSync(fixtures.inputJpgBooleanTest);
 
   [
     sharp.bool.and,
     sharp.bool.or,
     sharp.bool.eor
   ]
-  .forEach(function(op) {
-
-    it(op + ' operation, file', function(done) {
+  .forEach(function (op) {
+    it(op + ' operation, file', function (done) {
       sharp(fixtures.inputJpg)
         .resize(320, 240)
         .boolean(fixtures.inputJpgBooleanTest, op)
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual(320, info.width);
           assert.strictEqual(240, info.height);
@@ -28,11 +27,11 @@ describe('Boolean operation between two images', function() {
         });
     });
 
-    it(op + ' operation, buffer', function(done) {
+    it(op + ' operation, buffer', function (done) {
       sharp(fixtures.inputJpg)
         .resize(320, 240)
         .boolean(inputJpgBooleanTestBuffer, op)
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual(320, info.width);
           assert.strictEqual(240, info.height);
@@ -40,15 +39,15 @@ describe('Boolean operation between two images', function() {
         });
     });
 
-    it(op + ' operation, raw', function(done) {
+    it(op + ' operation, raw', function (done) {
       sharp(fixtures.inputJpgBooleanTest)
         .raw()
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           sharp(fixtures.inputJpg)
             .resize(320, 240)
             .boolean(data, op, { raw: info })
-            .toBuffer(function(err, data, info) {
+            .toBuffer(function (err, data, info) {
               if (err) throw err;
               assert.strictEqual(320, info.width);
               assert.strictEqual(240, info.height);
@@ -56,23 +55,22 @@ describe('Boolean operation between two images', function() {
             });
         });
     });
-
   });
 
-  it('Invalid operation', function() {
-    assert.throws(function() {
+  it('Invalid operation', function () {
+    assert.throws(function () {
       sharp().boolean(fixtures.inputJpgBooleanTest, 'fail');
     });
   });
 
-  it('Invalid operation, non-string', function() {
-    assert.throws(function() {
+  it('Invalid operation, non-string', function () {
+    assert.throws(function () {
       sharp().boolean(fixtures.inputJpgBooleanTest, null);
     });
   });
 
-  it('Missing input', function() {
-    assert.throws(function() {
+  it('Missing input', function () {
+    assert.throws(function () {
       sharp().boolean();
     });
   });

test/unit/cache.js

@@ -1,9 +1,9 @@
 'use strict';
 
-var sharp = require('../../index');
+const sharp = require('../../');
 
 // Define SHARP_TEST_WITHOUT_CACHE environment variable to prevent use of libvips' cache
 
-beforeEach(function() {
-  sharp.cache(process.env.SHARP_TEST_WITHOUT_CACHE ? false : true);
+beforeEach(function () {
+  sharp.cache(!process.env.SHARP_TEST_WITHOUT_CACHE);
 });

test/unit/clone.js

@@ -1,27 +1,26 @@
 'use strict';
 
-var fs = require('fs');
-var assert = require('assert');
+const fs = require('fs');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
-describe('Clone', function() {
-
-  beforeEach(function() {
+describe('Clone', function () {
+  beforeEach(function () {
     sharp.cache(false);
   });
-  afterEach(function() {
+  afterEach(function () {
     sharp.cache(true);
   });
 
-  it('Read from Stream and write to multiple Streams', function(done) {
-    var finishEventsExpected = 2;
+  it('Read from Stream and write to multiple Streams', function (done) {
+    let finishEventsExpected = 2;
     // Output stream 1
-    var output1 = fixtures.path('output.multi-stream.1.jpg');
-    var writable1 = fs.createWriteStream(output1);
-    writable1.on('finish', function() {
-      sharp(output1).toBuffer(function(err, data, info) {
+    const output1 = fixtures.path('output.multi-stream.1.jpg');
+    const writable1 = fs.createWriteStream(output1);
+    writable1.on('finish', function () {
+      sharp(output1).toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual(data.length, info.size);
@@ -36,10 +35,10 @@ describe('Clone', function() {
       });
     });
     // Output stream 2
-    var output2 = fixtures.path('output.multi-stream.2.jpg');
-    var writable2 = fs.createWriteStream(output2);
-    writable2.on('finish', function() {
-      sharp(output2).toBuffer(function(err, data, info) {
+    const output2 = fixtures.path('output.multi-stream.2.jpg');
+    const writable2 = fs.createWriteStream(output2);
+    writable2.on('finish', function () {
+      sharp(output2).toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual(data.length, info.size);
@@ -54,12 +53,11 @@ describe('Clone', function() {
       });
     });
     // Create parent instance
-    var rotator = sharp().rotate(90);
+    const rotator = sharp().rotate(90);
     // Cloned instances with differing dimensions
     rotator.clone().resize(320, 240).pipe(writable1);
     rotator.clone().resize(100, 122).pipe(writable2);
     // Go
     fs.createReadStream(fixtures.inputJpg).pipe(rotator);
   });
-
 });

test/unit/colourspace.js

@@ -1,40 +1,39 @@
 'use strict';
 
-var assert = require('assert');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
-describe('Colour space conversion', function() {
-
-  it('To greyscale', function(done) {
+describe('Colour space conversion', function () {
+  it('To greyscale', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .greyscale()
       .toFile(fixtures.path('output.greyscale-gamma-0.0.jpg'), done);
   });
 
-  it('To greyscale with gamma correction', function(done) {
+  it('To greyscale with gamma correction', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .gamma()
-      .greyscale()
+      .grayscale()
       .toFile(fixtures.path('output.greyscale-gamma-2.2.jpg'), done);
   });
 
-  it('Not to greyscale', function(done) {
+  it('Not to greyscale', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .greyscale(false)
       .toFile(fixtures.path('output.greyscale-not.jpg'), done);
   });
 
-  it('Greyscale with single channel output', function(done) {
+  it('Greyscale with single channel output', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .greyscale()
       .toColourspace('b-w')
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(1, info.channels);
         assert.strictEqual(320, info.width);
@@ -44,10 +43,10 @@ describe('Colour space conversion', function() {
   });
 
   if (sharp.format.tiff.input.file && sharp.format.webp.output.buffer) {
-    it('From 1-bit TIFF to sRGB WebP [slow]', function(done) {
+    it('From 1-bit TIFF to sRGB WebP [slow]', function (done) {
       sharp(fixtures.inputTiff)
         .webp()
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual(true, data.length > 0);
           assert.strictEqual('webp', info.format);
@@ -56,10 +55,10 @@ describe('Colour space conversion', function() {
     });
   }
 
-  it('From CMYK to sRGB', function(done) {
+  it('From CMYK to sRGB', function (done) {
     sharp(fixtures.inputJpgWithCmykProfile)
       .resize(320)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('jpeg', info.format);
@@ -68,12 +67,12 @@ describe('Colour space conversion', function() {
       });
   });
 
-  it('From CMYK to sRGB with white background, not yellow', function(done) {
+  it('From CMYK to sRGB with white background, not yellow', function (done) {
     sharp(fixtures.inputJpgWithCmykProfile)
       .resize(320, 240)
       .background('white')
       .embed()
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(320, info.width);
@@ -82,10 +81,10 @@ describe('Colour space conversion', function() {
       });
   });
 
-  it('From profile-less CMYK to sRGB', function(done) {
+  it('From profile-less CMYK to sRGB', function (done) {
     sharp(fixtures.inputJpgWithCmykNoProfile)
       .resize(320)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(320, info.width);
@@ -93,8 +92,8 @@ describe('Colour space conversion', function() {
       });
   });
 
-  it('Invalid input', function() {
-    assert.throws(function() {
+  it('Invalid input', function () {
+    assert.throws(function () {
       sharp(fixtures.inputJpg)
         .toColourspace(null);
     });

test/unit/convolve.js

@@ -1,24 +1,25 @@
 'use strict';
 
-var assert = require('assert');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
-describe('Convolve', function() {
-
-  it('specific convolution kernel 1', function(done) {
+describe('Convolve', function () {
+  it('specific convolution kernel 1', function (done) {
     sharp(fixtures.inputPngStripesV)
       .convolve({
         width: 3,
         height: 3,
         scale: 50,
         offset: 0,
-        kernel: [ 10, 20, 10,
-                   0,  0,  0,
-                  10, 20, 10 ]
+        kernel: [
+          10, 20, 10,
+          0, 0, 0,
+          10, 20, 10
+        ]
       })
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual('png', info.format);
         assert.strictEqual(320, info.width);
@@ -27,16 +28,18 @@ describe('Convolve', function() {
       });
   });
 
-  it('specific convolution kernel 2', function(done) {
+  it('specific convolution kernel 2', function (done) {
     sharp(fixtures.inputPngStripesH)
       .convolve({
         width: 3,
         height: 3,
-        kernel: [ 1, 0, 1,
-                  2, 0, 2,
-                  1, 0, 1 ]
+        kernel: [
+          1, 0, 1,
+          2, 0, 2,
+          1, 0, 1
+        ]
       })
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual('png', info.format);
         assert.strictEqual(320, info.width);
@@ -45,17 +48,19 @@ describe('Convolve', function() {
       });
   });
 
-  it('horizontal Sobel operator', function(done) {
+  it('horizontal Sobel operator', function (done) {
     sharp(fixtures.inputJpg)
       .resize(320, 240)
       .convolve({
         width: 3,
         height: 3,
-        kernel: [ -1, 0, 1,
-                  -2, 0, 2,
-                  -1, 0, 1 ]
+        kernel: [
+          -1, 0, 1,
+          -2, 0, 2,
+          -1, 0, 1
+        ]
       })
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(320, info.width);
@@ -64,14 +69,14 @@ describe('Convolve', function() {
       });
   });
 
-  describe('invalid kernel specification', function() {
-    it('missing', function() {
-      assert.throws(function() {
+  describe('invalid kernel specification', function () {
+    it('missing', function () {
+      assert.throws(function () {
         sharp(fixtures.inputJpg).convolve({});
       });
     });
-    it('incorrect data format', function() {
-      assert.throws(function() {
+    it('incorrect data format', function () {
+      assert.throws(function () {
         sharp(fixtures.inputJpg).convolve({
           width: 3,
           height: 3,
@@ -79,8 +84,8 @@ describe('Convolve', function() {
         });
       });
     });
-    it('incorrect dimensions', function() {
-      assert.throws(function() {
+    it('incorrect dimensions', function () {
+      assert.throws(function () {
         sharp(fixtures.inputJpg).convolve({
           width: 3,
           height: 4,

test/unit/cpplint.js

@@ -1,51 +0,0 @@
-'use strict';
-
-var fs = require('fs');
-var path = require('path');
-var assert = require('assert');
-
-var cpplint = require('node-cpplint/lib/');
-
-describe('cpplint', function() {
-
-  // Ignore cpplint failures, possibly newline-related, on Windows
-  if (process.platform !== 'win32') {
-    // List C++ source files
-    fs.readdirSync(path.join(__dirname, '..', '..', 'src')).filter(function(source) {
-      return source !== 'libvips';
-    }).forEach(function(source) {
-      var file = path.join('src', source);
-      it(file, function(done) {
-        // Lint each source file
-        cpplint({
-          files: [file],
-          linelength: 120,
-          filters: {
-            legal: {
-              copyright: false
-            },
-            build: {
-              include: false
-            },
-            whitespace: {
-              parens: false
-            },
-            runtime: {
-              indentation_namespace: false
-            }
-          }
-        }, function(err, report) {
-          if (err) {
-            throw err;
-          }
-          var expected = {};
-          expected[file] = [];
-          assert.deepEqual(expected, report);
-          done();
-        });
-      });
-
-    });
-  }
-
-});

test/unit/crop.js

@@ -1,12 +1,11 @@
 'use strict';
 
-var assert = require('assert');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
-
-describe('Crop', function() {
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
+describe('Crop', function () {
   [
     {
       name: 'North',
@@ -113,12 +112,12 @@ describe('Crop', function() {
       gravity: sharp.gravity.northwest,
       fixture: 'gravity-west.jpg'
     }
-  ].forEach(function(settings) {
-    it(settings.name + ' gravity', function(done) {
+  ].forEach(function (settings) {
+    it(settings.name + ' gravity', function (done) {
       sharp(fixtures.inputJpg)
         .resize(settings.width, settings.height)
         .crop(settings.gravity)
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual(settings.width, info.width);
           assert.strictEqual(settings.height, info.height);
@@ -127,11 +126,11 @@ describe('Crop', function() {
     });
   });
 
-  it('Allows specifying the gravity as a string', function(done) {
+  it('Allows specifying the gravity as a string', function (done) {
     sharp(fixtures.inputJpg)
       .resize(80, 320)
       .crop('east')
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(80, info.width);
         assert.strictEqual(320, info.height);
@@ -139,34 +138,33 @@ describe('Crop', function() {
       });
   });
 
-  it('Invalid values fail', function() {
-    assert.throws(function() {
+  it('Invalid values fail', function () {
+    assert.throws(function () {
       sharp().crop(9);
-    });
-    assert.throws(function() {
+    }, /Expected valid crop id\/name\/strategy for crop but received 9 of type number/);
+    assert.throws(function () {
       sharp().crop(1.1);
-    });
-    assert.throws(function() {
+    }, /Expected valid crop id\/name\/strategy for crop but received 1.1 of type number/);
+    assert.throws(function () {
       sharp().crop(-1);
-    });
-    assert.throws(function() {
+    }, /Expected valid crop id\/name\/strategy for crop but received -1 of type number/);
+    assert.throws(function () {
       sharp().crop('zoinks');
-    });
+    }, /Expected valid crop id\/name\/strategy for crop but received zoinks of type string/);
   });
 
-  it('Uses default value when none specified', function() {
-    assert.doesNotThrow(function() {
+  it('Uses default value when none specified', function () {
+    assert.doesNotThrow(function () {
       sharp().crop();
     });
   });
 
-  describe('Entropy-based strategy', function() {
-
-    it('JPEG', function(done) {
+  describe('Entropy-based strategy', function () {
+    it('JPEG', function (done) {
       sharp(fixtures.inputJpgWithCmykProfile)
         .resize(80, 320)
         .crop(sharp.strategy.entropy)
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual('jpeg', info.format);
           assert.strictEqual(3, info.channels);
@@ -178,11 +176,11 @@ describe('Crop', function() {
         });
     });
 
-    it('PNG', function(done) {
+    it('PNG', function (done) {
       sharp(fixtures.inputPngWithTransparency)
         .resize(320, 80)
         .crop(sharp.strategy.entropy)
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual('png', info.format);
           assert.strictEqual(4, info.channels);
@@ -193,16 +191,14 @@ describe('Crop', function() {
           fixtures.assertSimilar(fixtures.expected('crop-strategy.png'), data, done);
         });
     });
-
   });
 
-  describe('Attention strategy', function() {
-
-    it('JPEG', function(done) {
+  describe('Attention strategy', function () {
+    it('JPEG', function (done) {
       sharp(fixtures.inputJpgWithCmykProfile)
         .resize(80, 320)
         .crop(sharp.strategy.attention)
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual('jpeg', info.format);
           assert.strictEqual(3, info.channels);
@@ -214,11 +210,11 @@ describe('Crop', function() {
         });
     });
 
-    it('PNG', function(done) {
+    it('PNG', function (done) {
       sharp(fixtures.inputPngWithTransparency)
         .resize(320, 80)
         .crop(sharp.strategy.attention)
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual('png', info.format);
           assert.strictEqual(4, info.channels);
@@ -229,6 +225,5 @@ describe('Crop', function() {
           fixtures.assertSimilar(fixtures.expected('crop-strategy.png'), data, done);
         });
     });
-
   });
 });

test/unit/embed.js

@@ -1,18 +1,17 @@
 'use strict';
 
-var assert = require('assert');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
-describe('Embed', function() {
-
-  it('JPEG within PNG, no alpha channel', function(done) {
+describe('Embed', function () {
+  it('JPEG within PNG, no alpha channel', function (done) {
     sharp(fixtures.inputJpg)
       .embed()
       .resize(320, 240)
       .png()
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('png', info.format);
@@ -23,30 +22,28 @@ describe('Embed', function() {
       });
   });
 
-  if (sharp.format.webp.output.buffer) {
-    it('JPEG within WebP, to include alpha channel', function(done) {
-      sharp(fixtures.inputJpg)
-        .resize(320, 240)
-        .background({r: 0, g: 0, b: 0, a: 0})
-        .embed()
-        .webp()
-        .toBuffer(function(err, data, info) {
-          if (err) throw err;
-          assert.strictEqual(true, data.length > 0);
-          assert.strictEqual('webp', info.format);
-          assert.strictEqual(320, info.width);
-          assert.strictEqual(240, info.height);
-          assert.strictEqual(4, info.channels);
-          fixtures.assertSimilar(fixtures.expected('embed-3-into-4.webp'), data, done);
-        });
-    });
-  }
+  it('JPEG within WebP, to include alpha channel', function (done) {
+    sharp(fixtures.inputJpg)
+      .resize(320, 240)
+      .background({r: 0, g: 0, b: 0, alpha: 0})
+      .embed()
+      .webp()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('webp', info.format);
+        assert.strictEqual(320, info.width);
+        assert.strictEqual(240, info.height);
+        assert.strictEqual(4, info.channels);
+        fixtures.assertSimilar(fixtures.expected('embed-3-into-4.webp'), data, done);
+      });
+  });
 
-  it('PNG with alpha channel', function(done) {
+  it('PNG with alpha channel', function (done) {
     sharp(fixtures.inputPngWithTransparency)
       .resize(50, 50)
       .embed()
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('png', info.format);
@@ -57,11 +54,11 @@ describe('Embed', function() {
       });
   });
 
-  it('16-bit PNG with alpha channel', function(done) {
+  it('16-bit PNG with alpha channel', function (done) {
     sharp(fixtures.inputPngWithTransparency16bit)
       .resize(32, 16)
       .embed()
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('png', info.format);
@@ -72,12 +69,12 @@ describe('Embed', function() {
       });
   });
 
-  it('16-bit PNG with alpha channel onto RGBA', function(done) {
+  it('16-bit PNG with alpha channel onto RGBA', function (done) {
     sharp(fixtures.inputPngWithTransparency16bit)
       .resize(32, 16)
       .embed()
-      .background({r: 0, g: 0, b: 0, a: 0})
-      .toBuffer(function(err, data, info) {
+      .background({r: 0, g: 0, b: 0, alpha: 0})
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('png', info.format);
@@ -88,12 +85,12 @@ describe('Embed', function() {
       });
   });
 
-  it('PNG with 2 channels', function(done) {
+  it('PNG with 2 channels', function (done) {
     sharp(fixtures.inputPngWithGreyAlpha)
       .resize(32, 16)
       .embed()
-      .background({r: 0, g: 0, b: 0, a: 0})
-      .toBuffer(function(err, data, info) {
+      .background({r: 0, g: 0, b: 0, alpha: 0})
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('png', info.format);
@@ -104,11 +101,28 @@ describe('Embed', function() {
       });
   });
 
-  it('Enlarge and embed', function(done) {
+  it('embed TIFF in LAB colourspace onto RGBA background', function (done) {
+    sharp(fixtures.inputTiffCielab)
+      .resize(64, 128)
+      .embed()
+      .background({r: 255, g: 102, b: 0, alpha: 0.5})
+      .png()
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('png', info.format);
+        assert.strictEqual(64, info.width);
+        assert.strictEqual(128, info.height);
+        assert.strictEqual(4, info.channels);
+        fixtures.assertSimilar(fixtures.expected('embed-lab-into-rgba.png'), data, done);
+      });
+  });
+
+  it('Enlarge and embed', function (done) {
     sharp(fixtures.inputPngWithOneColor)
       .embed()
       .resize(320, 240)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);
         assert.strictEqual('png', info.format);
@@ -118,5 +132,4 @@ describe('Embed', function() {
         fixtures.assertSimilar(fixtures.expected('embed-enlarge.png'), data, done);
       });
   });
-
 });

test/unit/extend.js

@@ -1,18 +1,17 @@
 'use strict';
 
-var assert = require('assert');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
 describe('Extend', function () {
-
-  it('extend all sides equally with RGB', function(done) {
+  it('extend all sides equally with RGB', function (done) {
     sharp(fixtures.inputJpg)
       .resize(120)
       .background({r: 255, g: 0, b: 0})
       .extend(10)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(140, info.width);
         assert.strictEqual(118, info.height);
@@ -20,12 +19,12 @@ describe('Extend', function () {
       });
   });
 
-  it('extend sides unequally with RGBA', function(done) {
+  it('extend sides unequally with RGBA', function (done) {
     sharp(fixtures.inputPngWithTransparency16bit)
       .resize(120)
-      .background({r: 0, g: 0, b: 0, a: 0})
+      .background({r: 0, g: 0, b: 0, alpha: 0})
       .extend({top: 50, bottom: 0, left: 10, right: 35})
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(165, info.width);
         assert.strictEqual(170, info.height);
@@ -33,32 +32,47 @@ describe('Extend', function () {
       });
   });
 
-  it('missing parameter fails', function() {
-    assert.throws(function() {
+  it('missing parameter fails', function () {
+    assert.throws(function () {
       sharp().extend();
     });
   });
-  it('negative fails', function() {
-    assert.throws(function() {
+  it('negative fails', function () {
+    assert.throws(function () {
       sharp().extend(-1);
     });
   });
-  it('partial object fails', function() {
-    assert.throws(function() {
+  it('partial object fails', function () {
+    assert.throws(function () {
       sharp().extend({top: 1});
     });
   });
 
-  it('should add alpha channel before extending with a transparent Background', function( done ){
+  it('should add alpha channel before extending with a transparent Background', function (done) {
     sharp(fixtures.inputJpgWithLandscapeExif1)
-      .background({r: 0, g: 0, b: 0, a: 0})
-      .toFormat( sharp.format.png )
+      .background({r: 0, g: 0, b: 0, alpha: 0})
+      .toFormat(sharp.format.png)
       .extend({top: 0, bottom: 10, left: 0, right: 10})
-      .toBuffer( function(err, data, info){
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
         assert.strictEqual(610, info.width);
         assert.strictEqual(460, info.height);
         fixtures.assertSimilar(fixtures.expected('addAlphaChanelBeforeExtend.png'), data, done);
       });
   });
 
+  it('PNG with 2 channels', function (done) {
+    sharp(fixtures.inputPngWithGreyAlpha)
+      .background('transparent')
+      .extend({top: 0, bottom: 20, left: 0, right: 20})
+      .toBuffer(function (err, data, info) {
+        if (err) throw err;
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('png', info.format);
+        assert.strictEqual(420, info.width);
+        assert.strictEqual(320, info.height);
+        assert.strictEqual(4, info.channels);
+        fixtures.assertSimilar(fixtures.expected('extend-2channel.png'), data, done);
+      });
+  });
 });

test/unit/extract.js

@@ -1,16 +1,15 @@
 'use strict';
 
-var assert = require('assert');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
-describe('Partial image extraction', function() {
-
-  it('JPEG', function(done) {
+describe('Partial image extraction', function () {
+  it('JPEG', function (done) {
     sharp(fixtures.inputJpg)
       .extract({ left: 2, top: 2, width: 20, height: 20 })
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(20, info.width);
         assert.strictEqual(20, info.height);
@@ -18,10 +17,10 @@ describe('Partial image extraction', function() {
       });
   });
 
-  it('PNG', function(done) {
+  it('PNG', function (done) {
     sharp(fixtures.inputPng)
       .extract({ left: 200, top: 300, width: 400, height: 200 })
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(400, info.width);
         assert.strictEqual(200, info.height);
@@ -30,10 +29,10 @@ describe('Partial image extraction', function() {
   });
 
   if (sharp.format.webp.output.file) {
-    it('WebP', function(done) {
+    it('WebP', function (done) {
       sharp(fixtures.inputWebP)
         .extract({ left: 100, top: 50, width: 125, height: 200 })
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual(125, info.width);
           assert.strictEqual(200, info.height);
@@ -43,11 +42,11 @@ describe('Partial image extraction', function() {
   }
 
   if (sharp.format.tiff.output.file) {
-    it('TIFF', function(done) {
+    it('TIFF', function (done) {
       sharp(fixtures.inputTiff)
         .extract({ left: 34, top: 63, width: 341, height: 529 })
         .jpeg()
-        .toBuffer(function(err, data, info) {
+        .toBuffer(function (err, data, info) {
           if (err) throw err;
           assert.strictEqual(341, info.width);
           assert.strictEqual(529, info.height);
@@ -56,11 +55,11 @@ describe('Partial image extraction', function() {
     });
   }
 
-  it('Before resize', function(done) {
+  it('Before resize', function (done) {
     sharp(fixtures.inputJpg)
       .extract({ left: 10, top: 10, width: 10, height: 500 })
       .resize(100, 100)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(100, info.width);
         assert.strictEqual(100, info.height);
@@ -68,12 +67,12 @@ describe('Partial image extraction', function() {
       });
   });
 
-  it('After resize and crop', function(done) {
+  it('After resize and crop', function (done) {
     sharp(fixtures.inputJpg)
       .resize(500, 500)
       .crop(sharp.gravity.north)
       .extract({ left: 10, top: 10, width: 100, height: 100 })
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(100, info.width);
         assert.strictEqual(100, info.height);
@@ -81,13 +80,13 @@ describe('Partial image extraction', function() {
       });
   });
 
-  it('Before and after resize and crop', function(done) {
+  it('Before and after resize and crop', function (done) {
     sharp(fixtures.inputJpg)
       .extract({ left: 0, top: 0, width: 700, height: 700 })
       .resize(500, 500)
       .crop(sharp.gravity.north)
       .extract({ left: 10, top: 10, width: 100, height: 100 })
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(100, info.width);
         assert.strictEqual(100, info.height);
@@ -95,11 +94,11 @@ describe('Partial image extraction', function() {
       });
   });
 
-  it('Extract then rotate', function(done) {
+  it('Extract then rotate', function (done) {
     sharp(fixtures.inputPngWithGreyAlpha)
       .extract({ left: 20, top: 10, width: 380, height: 280 })
       .rotate(90)
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(280, info.width);
         assert.strictEqual(380, info.height);
@@ -107,81 +106,81 @@ describe('Partial image extraction', function() {
       });
   });
 
-  it('Rotate then extract', function(done) {
+  it('Rotate then extract', function (done) {
     sharp(fixtures.inputPngWithGreyAlpha)
       .rotate(90)
       .extract({ left: 20, top: 10, width: 280, height: 380 })
-      .toBuffer(function(err, data, info) {
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(280, info.width);
         assert.strictEqual(380, info.height);
-        fixtures.assertSimilar(fixtures.expected('rotate-extract.jpg'), data, done);
+        fixtures.assertSimilar(fixtures.expected('rotate-extract.jpg'), data, { threshold: 6 }, done);
       });
   });
 
-  describe('Invalid parameters', function() {
+  describe('Invalid parameters', function () {
     describe('using the legacy extract(top,left,width,height) syntax', function () {
-      it('String top', function() {
-        assert.throws(function() {
+      it('String top', function () {
+        assert.throws(function () {
           sharp(fixtures.inputJpg).extract('spoons', 10, 10, 10);
         });
       });
 
-      it('Non-integral left', function() {
-        assert.throws(function() {
+      it('Non-integral left', function () {
+        assert.throws(function () {
           sharp(fixtures.inputJpg).extract(10, 10.2, 10, 10);
         });
       });
 
-      it('Negative width - negative', function() {
-        assert.throws(function() {
+      it('Negative width - negative', function () {
+        assert.throws(function () {
           sharp(fixtures.inputJpg).extract(10, 10, -10, 10);
         });
       });
 
-      it('Null height', function() {
-        assert.throws(function() {
+      it('Null height', function () {
+        assert.throws(function () {
           sharp(fixtures.inputJpg).extract(10, 10, 10, null);
         });
       });
     });
 
-    it('Undefined', function() {
-      assert.throws(function() {
+    it('Undefined', function () {
+      assert.throws(function () {
         sharp(fixtures.inputJpg).extract();
       });
     });
 
-    it('String top', function() {
-      assert.throws(function() {
+    it('String top', function () {
+      assert.throws(function () {
         sharp(fixtures.inputJpg).extract({ left: 10, top: 'spoons', width: 10, height: 10 });
       });
     });
 
-    it('Non-integral left', function() {
-      assert.throws(function() {
+    it('Non-integral left', function () {
+      assert.throws(function () {
         sharp(fixtures.inputJpg).extract({ left: 10.2, top: 10, width: 10, height: 10 });
       });
     });
 
-    it('Negative width - negative', function() {
-      assert.throws(function() {
+    it('Negative width - negative', function () {
+      assert.throws(function () {
         sharp(fixtures.inputJpg).extract({ left: 10, top: 10, width: -10, height: 10 });
       });
     });
 
-    it('Null height', function() {
-      assert.throws(function() {
+    it('Null height', function () {
+      assert.throws(function () {
         sharp(fixtures.inputJpg).extract({ left: 10, top: 10, width: 10, height: null });
       });
     });
 
-    it('Bad image area', function(done) {
+    it('Bad image area', function (done) {
       sharp(fixtures.inputJpg)
         .extract({ left: 3000, top: 10, width: 10, height: 10 })
-        .toBuffer(function(err) {
+        .toBuffer(function (err) {
           assert(err instanceof Error);
-          assert.strictEqual(err.message, "extract_area: bad extract area\n");
+          assert.strictEqual(err.message, 'extract_area: bad extract area\n');
           done();
         });
     });

test/unit/extractChannel.js

@@ -1,17 +1,16 @@
 'use strict';
 
-var assert = require('assert');
+const assert = require('assert');
 
-var sharp = require('../../index');
-var fixtures = require('../fixtures');
+const sharp = require('../../');
+const fixtures = require('../fixtures');
 
-describe('Image channel extraction', function() {
-
-  it('Red channel', function(done) {
+describe('Image channel extraction', function () {
+  it('Red channel', function (done) {
     sharp(fixtures.inputJpg)
       .extractChannel('red')
-      .resize(320,240)
-      .toBuffer(function(err, data, info) {
+      .resize(320, 240)
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);
@@ -19,11 +18,11 @@ describe('Image channel extraction', function() {
       });
   });
 
-  it('Green channel', function(done) {
+  it('Green channel', function (done) {
     sharp(fixtures.inputJpg)
       .extractChannel('green')
-      .resize(320,240)
-      .toBuffer(function(err, data, info) {
+      .resize(320, 240)
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);
@@ -31,11 +30,11 @@ describe('Image channel extraction', function() {
       });
   });
 
-  it('Blue channel', function(done) {
+  it('Blue channel', function (done) {
     sharp(fixtures.inputJpg)
       .extractChannel('blue')
-      .resize(320,240)
-      .toBuffer(function(err, data, info) {
+      .resize(320, 240)
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);
@@ -43,11 +42,11 @@ describe('Image channel extraction', function() {
       });
   });
 
-  it('Blue channel by number', function(done) {
+  it('Blue channel by number', function (done) {
     sharp(fixtures.inputJpg)
       .extractChannel(2)
-      .resize(320,240)
-      .toBuffer(function(err, data, info) {
+      .resize(320, 240)
+      .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);
@@ -55,27 +54,26 @@ describe('Image channel extraction', function() {
       });
   });
 
-  it('Invalid channel number', function() {
-    assert.throws(function() {
+  it('Invalid channel number', function () {
+    assert.throws(function () {
       sharp(fixtures.inputJpg)
         .extractChannel(-1);
     });
   });
 
-  it('No arguments', function() {
-    assert.throws(function() {
+  it('No arguments', function () {
+    assert.throws(function () {
       sharp(fixtures.inputJpg)
         .extractChannel();
     });
   });
 
-  it('Non-existant channel', function(done) {
+  it('Non-existant channel', function (done) {
     sharp(fixtures.inputPng)
       .extractChannel(1)
-      .toBuffer(function(err) {
+      .toBuffer(function (err) {
         assert(err instanceof Error);
         done();
       });
   });
-
 });