Release v0.25.4

binding.gyp

@@ -29,10 +29,22 @@
           'Release': {
             'msvs_settings': {
               'VCCLCompilerTool': {
-                'ExceptionHandling': 1
+                'ExceptionHandling': 1,
+                'WholeProgramOptimization': 'true'
+              },
+              'VCLibrarianTool': {
+                'AdditionalOptions': [
+                  '/LTCG:INCREMENTAL'
+                ]
               },
               'VCLinkerTool': {
-                'ImageHasSafeExceptionHandlers': 'false'
+                'ImageHasSafeExceptionHandlers': 'false',
+                'OptimizeReferences': 2,
+                'EnableCOMDATFolding': 2,
+                'LinkIncremental': 1,
+                'AdditionalOptions': [
+                  '/LTCG:INCREMENTAL'
+                ]
               }
             },
             'msvs_disabled_warnings': [
@@ -121,7 +133,7 @@
               '../vendor/lib/libglib-2.0.0.dylib',
               '../vendor/lib/libgobject-2.0.0.dylib',
               # Ensure runtime linking is relative to sharp.node
-              '-rpath \'@loader_path/../../vendor/lib\''
+              '-Wl,-s -rpath \'@loader_path/../../vendor/lib\''
             ]
           }],
           ['OS == "linux"', {
@@ -164,7 +176,7 @@
               '../vendor/lib/libxml2.so',
               '../vendor/lib/libz.so',
               # Ensure runtime linking is relative to sharp.node
-              '-Wl,--disable-new-dtags -Wl,-rpath=\'$${ORIGIN}/../../vendor/lib\''
+              '-Wl,-s -Wl,--disable-new-dtags -Wl,-rpath=\'$${ORIGIN}/../../vendor/lib\''
             ]
           }]
         ]
@@ -204,10 +216,22 @@
           ['OS == "win"', {
             'msvs_settings': {
               'VCCLCompilerTool': {
-                'ExceptionHandling': 1
+                'ExceptionHandling': 1,
+                'WholeProgramOptimization': 'true'
+              },
+              'VCLibrarianTool': {
+                'AdditionalOptions': [
+                  '/LTCG:INCREMENTAL'
+                ]
               },
               'VCLinkerTool': {
-                'ImageHasSafeExceptionHandlers': 'false'
+                'ImageHasSafeExceptionHandlers': 'false',
+                'OptimizeReferences': 2,
+                'EnableCOMDATFolding': 2,
+                'LinkIncremental': 1,
+                'AdditionalOptions': [
+                  '/LTCG:INCREMENTAL'
+                ]
               }
             },
             'msvs_disabled_warnings': [

docs/api-channel.md

@@ -42,7 +42,7 @@ Extract a single channel from a multi-channel image.
 
 ### Parameters
 
--   `channel` **([number][1] \| [string][2])** zero-indexed band number to extract, or `red`, `green` or `blue` as alternative to `0`, `1` or `2` respectively.
+-   `channel` **([number][1] \| [string][2])** zero-indexed channel/band number to extract, or `red`, `green`, `blue` or `alpha`.
 
 ### Examples
 

docs/api-constructor.md

@@ -2,32 +2,42 @@
 
 ## Sharp
 
+Constructor factory to create an instance of `sharp`, to which further methods are chained.
+
+JPEG, PNG, WebP or TIFF format image data can be streamed out from this object.
+When using Stream based output, derived attributes are available from the `info` event.
+
+Non-critical problems encountered during processing are emitted as `warning` events.
+
+Implements the [stream.Duplex][1] class.
+
 ### Parameters
 
--   `input` **([Buffer][1] \| [String][2])?** if present, can be
+-   `input` **([Buffer][2] \| [string][3])?** if present, can be
      a Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
      a String containing the filesystem path to an JPEG, PNG, WebP, GIF, SVG or TIFF image file.
      JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data can be streamed into the object when not present.
--   `options` **[Object][3]?** if present, is an Object with optional attributes.
+-   `options` **[Object][4]?** if present, is an Object with optional attributes.
-    -   `options.failOnError` **[Boolean][4]** by default halt processing and raise an error when loading invalid images.
+    -   `options.failOnError` **[boolean][5]** by default halt processing and raise an error when loading invalid images.
          Set this flag to `false` if you'd rather apply a "best effort" to decode images, even if the data is corrupt or invalid. (optional, default `true`)
-    -   `options.limitInputPixels` **([Number][5] \| [Boolean][4])** Do not process input images where the number of pixels
+    -   `options.limitInputPixels` **([number][6] \| [boolean][5])** Do not process input images where the number of pixels
          (width x height) exceeds this limit. Assumes image dimensions contained in the input metadata can be trusted.
          An integral Number of pixels, zero or false to remove limit, true to use default limit of 268402689 (0x3FFF x 0x3FFF). (optional, default `268402689`)
-    -   `options.sequentialRead` **[Boolean][4]** Set this to `true` to use sequential rather than random access where possible.
+    -   `options.sequentialRead` **[boolean][5]** Set this to `true` to use sequential rather than random access where possible.
          This can reduce memory usage and might improve performance on some systems. (optional, default `false`)
-    -   `options.density` **[Number][5]** number representing the DPI for vector images. (optional, default `72`)
+    -   `options.density` **[number][6]** number representing the DPI for vector images. (optional, default `72`)
-    -   `options.pages` **[Number][5]** number of pages to extract for multi-page input (GIF, TIFF, PDF), use -1 for all pages. (optional, default `1`)
+    -   `options.pages` **[number][6]** number of pages to extract for multi-page input (GIF, TIFF, PDF), use -1 for all pages. (optional, default `1`)
-    -   `options.page` **[Number][5]** page number to start extracting from for multi-page input (GIF, TIFF, PDF), zero based. (optional, default `0`)
+    -   `options.page` **[number][6]** page number to start extracting from for multi-page input (GIF, TIFF, PDF), zero based. (optional, default `0`)
-    -   `options.raw` **[Object][3]?** describes raw pixel input image data. See `raw()` for pixel ordering.
+    -   `options.level` **[number][6]** level to extract from a multi-level input (OpenSlide), zero based. (optional, default `0`)
-        -   `options.raw.width` **[Number][5]?** 
+    -   `options.raw` **[Object][4]?** describes raw pixel input image data. See `raw()` for pixel ordering.
-        -   `options.raw.height` **[Number][5]?** 
+        -   `options.raw.width` **[number][6]?** 
-        -   `options.raw.channels` **[Number][5]?** 1-4
+        -   `options.raw.height` **[number][6]?** 
-    -   `options.create` **[Object][3]?** describes a new image to be created.
+        -   `options.raw.channels` **[number][6]?** 1-4
-        -   `options.create.width` **[Number][5]?** 
+    -   `options.create` **[Object][4]?** describes a new image to be created.
-        -   `options.create.height` **[Number][5]?** 
+        -   `options.create.width` **[number][6]?** 
-        -   `options.create.channels` **[Number][5]?** 3-4
+        -   `options.create.height` **[number][6]?** 
-        -   `options.create.background` **([String][2] \| [Object][3])?** parsed by the [color][6] module to extract values for red, green, blue and alpha.
+        -   `options.create.channels` **[number][6]?** 3-4
+        -   `options.create.background` **([string][3] \| [Object][4])?** parsed by the [color][7] module to extract values for red, green, blue and alpha.
 
 ### Examples
 
@@ -68,9 +78,9 @@ sharp({
 .then( ... );
 ```
 
--   Throws **[Error][7]** Invalid parameters
+-   Throws **[Error][8]** Invalid parameters
 
-Returns **[Sharp][8]** 
+Returns **[Sharp][9]** 
 
 ## clone
 
@@ -138,20 +148,22 @@ Promise.all(promises)
   });
 ```
 
-Returns **[Sharp][8]** 
+Returns **[Sharp][9]** 
 
-[1]: https://nodejs.org/api/buffer.html
+[1]: http://nodejs.org/api/stream.html#stream_class_stream_duplex
 
-[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+[2]: https://nodejs.org/api/buffer.html
 
-[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
 
-[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
 
-[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
 
-[6]: https://www.npmjs.org/package/color
+[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
 
-[7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+[7]: https://www.npmjs.org/package/color
 
-[8]: #sharp
+[8]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+
+[9]: #sharp

docs/api-input.md

@@ -20,6 +20,7 @@ A `Promise` is returned when `callback` is not provided.
 -   `loop`: Number of times to loop an animated image, zero refers to a continuous loop.
 -   `delay`: Delay in ms between each page in an animated image, provided as an array of integers.
 -   `pagePrimary`: Number of the primary page in a HEIF image
+-   `levels`: Details of each level in a multi-level image provided as an array of objects, requires libvips compiled with support for OpenSlide
 -   `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
@@ -70,6 +71,7 @@ A `Promise` is returned when `callback` is not provided.
     -   `maxY` (y-coordinate of one of the pixel where the maximum lies)
 -   `isOpaque`: Is the image fully opaque? Will be `true` if the image has no alpha channel or if every pixel is fully opaque.
 -   `entropy`: Histogram-based estimation of greyscale entropy, discarding alpha channel if any (experimental)
+-   `sharpness`: Estimation of greyscale sharpness based on the standard deviation of a Laplacian convolution, discarding alpha channel if any (experimental)
 
 ### Parameters
 
@@ -86,6 +88,10 @@ image
   });
 ```
 
+```javascript
+const { entropy, sharpness } = await sharp(input).stats();
+```
+
 Returns **[Promise][5]<[Object][6]>** 
 
 [1]: https://libvips.github.io/libvips/API/current/VipsImage.html#VipsInterpretation

docs/api-output.md

@@ -140,20 +140,22 @@ Returns **Sharp**
 
 Use these JPEG options for output image.
 
+Some of these options require the use of a globally-installed libvips compiled with support for mozjpeg.
+
 ### Parameters
 
 -   `options` **[Object][6]?** output options
     -   `options.quality` **[number][9]** quality, integer 1-100 (optional, default `80`)
     -   `options.progressive` **[boolean][7]** use progressive (interlace) scan (optional, default `false`)
     -   `options.chromaSubsampling` **[string][2]** for quality < 90, set to '4:4:4' to prevent chroma subsampling otherwise defaults to '4:2:0' (use chroma subsampling); for quality >= 90 chroma is never subsampled (optional, default `'4:2:0'`)
+    -   `options.optimiseCoding` **[boolean][7]** optimise Huffman coding tables (optional, default `true`)
+    -   `options.optimizeCoding` **[boolean][7]** alternative spelling of optimiseCoding (optional, default `true`)
     -   `options.trellisQuantisation` **[boolean][7]** apply trellis quantisation, requires libvips compiled with support for mozjpeg (optional, default `false`)
     -   `options.overshootDeringing` **[boolean][7]** apply overshoot deringing, requires libvips compiled with support for mozjpeg (optional, default `false`)
     -   `options.optimiseScans` **[boolean][7]** optimise progressive scans, forces progressive, requires libvips compiled with support for mozjpeg (optional, default `false`)
-    -   `options.optimizeScans` **[boolean][7]** alternative spelling of optimiseScans (optional, default `false`)
+    -   `options.optimizeScans` **[boolean][7]** alternative spelling of optimiseScans, requires libvips compiled with support for mozjpeg (optional, default `false`)
-    -   `options.optimiseCoding` **[boolean][7]** optimise Huffman coding tables (optional, default `true`)
-    -   `options.optimizeCoding` **[boolean][7]** alternative spelling of optimiseCoding (optional, default `true`)
     -   `options.quantisationTable` **[number][9]** quantization table to use, integer 0-8, requires libvips compiled with support for mozjpeg (optional, default `0`)
-    -   `options.quantizationTable` **[number][9]** alternative spelling of quantisationTable (optional, default `0`)
+    -   `options.quantizationTable` **[number][9]** alternative spelling of quantisationTable, requires libvips compiled with support for mozjpeg (optional, default `0`)
     -   `options.force` **[boolean][7]** force JPEG output, otherwise attempt to use input format (optional, default `true`)
 
 ### Examples
@@ -179,6 +181,8 @@ Use these PNG options for output image.
 PNG output is always full colour at 8 or 16 bits per pixel.
 Indexed PNG input at 1, 2 or 4 bits per pixel is converted to 8 bits per pixel.
 
+Some of these options require the use of a globally-installed libvips compiled with support for libimagequant (GPL).
+
 ### Parameters
 
 -   `options` **[Object][6]?** 
@@ -186,10 +190,10 @@ Indexed PNG input at 1, 2 or 4 bits per pixel is converted to 8 bits per pixel.
     -   `options.compressionLevel` **[number][9]** zlib compression level, 0-9 (optional, default `9`)
     -   `options.adaptiveFiltering` **[boolean][7]** use adaptive row filtering (optional, default `false`)
     -   `options.palette` **[boolean][7]** quantise to a palette-based image with alpha transparency support, requires libvips compiled with support for libimagequant (optional, default `false`)
-    -   `options.quality` **[number][9]** use the lowest number of colours needed to achieve given quality, requires libvips compiled with support for libimagequant (optional, default `100`)
+    -   `options.quality` **[number][9]** use the lowest number of colours needed to achieve given quality, sets `palette` to `true`, requires libvips compiled with support for libimagequant (optional, default `100`)
-    -   `options.colours` **[number][9]** maximum number of palette entries, requires libvips compiled with support for libimagequant (optional, default `256`)
+    -   `options.colours` **[number][9]** maximum number of palette entries, sets `palette` to `true`, requires libvips compiled with support for libimagequant (optional, default `256`)
-    -   `options.colors` **[number][9]** alternative spelling of `options.colours`, requires libvips compiled with support for libimagequant (optional, default `256`)
+    -   `options.colors` **[number][9]** alternative spelling of `options.colours`, sets `palette` to `true`, requires libvips compiled with support for libimagequant (optional, default `256`)
-    -   `options.dither` **[number][9]** level of Floyd-Steinberg error diffusion, requires libvips compiled with support for libimagequant (optional, default `1.0`)
+    -   `options.dither` **[number][9]** level of Floyd-Steinberg error diffusion, sets `palette` to `true`, requires libvips compiled with support for libimagequant (optional, default `1.0`)
     -   `options.force` **[boolean][7]** force PNG output, otherwise attempt to use input format (optional, default `true`)
 
 ### Examples

docs/changelog.md

@@ -4,6 +4,29 @@
 
 Requires libvips v8.9.1
 
+### v0.25.4 - 12th June 2020
+
+* Allow libvips binary location override where version is appended.
+  [#2217](https://github.com/lovell/sharp/pull/2217)
+  [@malice00](https://github.com/malice00)
+
+* Enable PNG palette when setting quality, colours, colors or dither.
+  [#2226](https://github.com/lovell/sharp/pull/2226)
+  [@romaleev](https://github.com/romaleev)
+
+* Add `level` constructor option to use a specific level of a multi-level image.
+  Expose `levels` metadata for multi-level images.
+  [#2222](https://github.com/lovell/sharp/issues/2222)
+
+* Add support for named `alpha` channel to `extractChannel` operation.
+  [#2138](https://github.com/lovell/sharp/issues/2138)
+
+* Add experimental `sharpness` calculation to `stats()` response.
+  [#2251](https://github.com/lovell/sharp/issues/2251)
+
+* Emit `warning` event for non-critical processing problems.
+  [#2032](https://github.com/lovell/sharp/issues/2032)
+
 ### v0.25.3 - 17th May 2020
 
 * Ensure libvips is initialised only once, improves worker thread safety.

docs/humans.txt

@@ -182,3 +182,9 @@ GitHub: https://github.com/edsilv
 
 Name: Dumitru Deveatii
 GitHub: https://github.com/dimadeveatii
+
+Name: Roland Asmann
+GitHub: https://github.com/malice00
+
+Name: Roman Malieiev
+GitHub: https://github.com/romaleev

docs/index.html

@@ -12,10 +12,11 @@
   <link rel="apple-touch-icon-precomposed" sizes="114x114" href="https://pixel.plumbing/px/114x114/sharp-logo.svg">
   <link rel="apple-touch-icon-precomposed" sizes="72x72" href="https://pixel.plumbing/px/72x72/sharp-logo.svg">
   <link rel="apple-touch-icon-precomposed" href="https://pixel.plumbing/px/57x57/sharp-logo.svg">
-  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/docute@4/dist/docute.min.css">
+  <style>/* https://cdn.jsdelivr.net/npm/docute@4/dist/docute.min.css */ body{margin:0;color:var(--text-color);background:var(--page-background);text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;font:16px/1.7 -apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif}*{box-sizing:border-box}a{color:var(--link-color);text-decoration:none}.page-content>:first-child{margin-top:0}.page-content.has-page-title>h2:first-child{margin-top:7rem}.page-content h2,.page-content h3{font-weight:300;line-height:1.2}.page-content h2{font-size:2rem;border-bottom:1px solid var(--border-color);margin-top:7rem;padding-bottom:5px}.page-content h3{font-size:1.7rem;margin:40px 0 30px}.page-content code{font-family:var(--code-font);font-size:90%;background:var(--inline-code-background);border-radius:4px;padding:3px 5px;color:var(--inline-code-color)}.page-content>ul{padding-left:20px;margin:1rem 0}.page-content img{max-width:100%}@-webkit-keyframes blink-data-v-4f620c69{to{opacity:.2}}@keyframes blink-data-v-4f620c69{0%{opacity:.2}20%{opacity:1}to{opacity:.2}}</style>
   <link rel="author" href="/humans.txt" type="text/plain">
-  <link rel="preload" href="https://cdn.jsdelivr.net/gh/lovell/sharp@v0.25.3/docs/README.md" as="fetch" type="text/markdown" crossorigin>
+  <link rel="preload" href="https://cdn.jsdelivr.net/gh/lovell/sharp@v0.25.4/docs/README.md" as="fetch" type="text/markdown" crossorigin>
   <link rel="preload" href="https://cdn.jsdelivr.net/gh/lovell/sharp@master/docs/image/sharp-logo.svg" as="image" type="image/svg+xml" crossorigin>
+  <link rel="dns-prefetch" href="https://pixel.plumbing">
   <link rel="dns-prefetch" href="https://www.google-analytics.com">
   <script type="application/ld+json">
   {
@@ -65,8 +66,8 @@
 <body>
   <div id="docute"></div>
   <script src="https://cdn.jsdelivr.net/npm/docute@4/dist/docute.min.js"></script>
-  <script src="https://cdn.jsdelivr.net/npm/docute-google-analytics@1/dist/index.min.js"></script>
   <script>
+    /* https://cdn.jsdelivr.net/npm/docute-google-analytics@1/dist/index.min.js */ !function(e,n){"object"==typeof exports&&"undefined"!=typeof module?module.exports=n():"function"==typeof define&&define.amd?define(n):(e=e||self).docuteGoogleAnalytics=n()}(this,function(){"use strict";function e(e){var n;window.ga||((n=document.createElement("script")).async=!0,n.src="https://www.google-analytics.com/analytics.js",document.body.appendChild(n),window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)},ga.l=Number(new Date),ga("create",e,"auto"))}function n(n,t){e(t),ga("set","page",n),ga("send","pageview")}return function(e){return{name:"@google-analytics",extend:function(t){!function(e,t){"function"==typeof e?e(function(e){n(e,t)}):e.afterEach(function(e){n(e.fullPath,t)})}(t.router,e)}}}});
     const docuteApiTitlePlugin = {
       name: 'apiTitle',
       extend(api) {
@@ -131,7 +132,7 @@
         docuteApiTitlePlugin,
         docuteApiSearchPlugin
       ],
-      sourcePath: 'https://cdn.jsdelivr.net/gh/lovell/sharp@v0.25.3/docs',
+      sourcePath: 'https://cdn.jsdelivr.net/gh/lovell/sharp@v0.25.4/docs',
       nav: [
         {
           title: 'Funding',

docs/install.md

@@ -81,24 +81,41 @@ Building from source requires:
 
 This is an advanced approach that most people will not require.
 
-To install the prebuilt libvips binaries from a custom URL,
+To install the prebuilt sharp binaries from a custom URL,
-set the `sharp_dist_base_url` npm config option
+set the `sharp_binary_host` npm config option
-or the `SHARP_DIST_BASE_URL` environment variable.
+or the `npm_config_sharp_binary_host` environment variable.
 
-For example, both of the following will result in an attempt to download the file located at
+To install the prebuilt libvips binaries from a custom URL,
-`https://hostname/path/libvips-x.y.z-platform.tar.gz`.
+set the `sharp_libvips_binary_host` npm config option
+or the `npm_config_sharp_libvips_binary_host` environment variable.
+
+The version subpath and file name are appended to these.
+
+For example, if `sharp_libvips_binary_host` is set to `https://hostname/path`
+and the libvips version is `1.2.3` then the resultant URL will be
+`https://hostname/path/v1.2.3/libvips-1.2.3-platform-arch.tar.gz`.
+
+See the Chinese mirror below for a further example.
+
+## Chinese mirror
+
+Alibaba provide a mirror site based in China containing binaries for both sharp and libvips.
+
+To use this either set the following configuration:
 
 ```sh
-npm config set sharp_dist_base_url "https://hostname/path/"
+npm config set sharp_binary_host "https://npm.taobao.org/mirrors/sharp"
+npm config set sharp_libvips_binary_host "https://npm.taobao.org/mirrors/sharp-libvips"
 npm install sharp
 ```
 
-```sh
+or set the following environment variables:
-SHARP_DIST_BASE_URL="https://hostname/path/" npm install sharp
-```
 
-To install the prebuilt sharp binaries from a custom URL, please see
+```sh
-[https://github.com/prebuild/prebuild-install#custom-binaries](https://github.com/prebuild/prebuild-install#custom-binaries)
+npm_config_sharp_binary_host="https://npm.taobao.org/mirrors/sharp" \
+  npm_config_sharp_libvips_binary_host "https://npm.taobao.org/mirrors/sharp-libvips" \
+  npm install sharp
+```
 
 ## FreeBSD
 

install/libvips.js

@@ -21,7 +21,8 @@ const minimumGlibcVersionByArch = {
 };
 
 const { minimumLibvipsVersion, minimumLibvipsVersionLabelled } = libvips;
-const distBaseUrl = process.env.npm_config_sharp_dist_base_url || process.env.SHARP_DIST_BASE_URL || `https://github.com/lovell/sharp-libvips/releases/download/v${minimumLibvipsVersionLabelled}/`;
+const distHost = process.env.npm_config_sharp_libvips_binary_host || 'https://github.com/lovell/sharp-libvips/releases/download';
+const distBaseUrl = process.env.npm_config_sharp_dist_base_url || process.env.SHARP_DIST_BASE_URL || `${distHost}/v${minimumLibvipsVersionLabelled}/`;
 
 const fail = function (err) {
   npmLog.error('sharp', err.message);

lib/channel.js

@@ -60,22 +60,19 @@ function ensureAlpha () {
  *     // green.jpg is a greyscale image containing the green channel of the input
  *    });
  *
- * @param {number|string} channel - zero-indexed band number to extract, or `red`, `green` or `blue` as alternative to `0`, `1` or `2` respectively.
+ * @param {number|string} channel - zero-indexed channel/band number to extract, or `red`, `green`, `blue` or `alpha`.
  * @returns {Sharp}
  * @throws {Error} Invalid channel
  */
 function extractChannel (channel) {
-  if (channel === 'red') {
+  const channelMap = { red: 0, green: 1, blue: 2, alpha: 3 };
-    channel = 0;
+  if (Object.keys(channelMap).includes(channel)) {
-  } else if (channel === 'green') {
+    channel = channelMap[channel];
-    channel = 1;
-  } else if (channel === 'blue') {
-    channel = 2;
   }
   if (is.integer(channel) && is.inRange(channel, 0, 4)) {
     this.options.extractChannel = channel;
   } else {
-    throw is.invalidParameterError('channel', 'integer or one of: red, green, blue', channel);
+    throw is.invalidParameterError('channel', 'integer or one of: red, green, blue, alpha', channel);
   }
   return this;
 }

lib/constructor.js

@@ -38,15 +38,20 @@ try {
 const debuglog = util.debuglog('sharp');
 
 /**
- * @constructs sharp
- *
  * Constructor factory to create an instance of `sharp`, to which further methods are chained.
  *
  * JPEG, PNG, WebP or TIFF format image data can be streamed out from this object.
  * When using Stream based output, derived attributes are available from the `info` event.
  *
+ * Non-critical problems encountered during processing are emitted as `warning` events.
+ *
  * Implements the [stream.Duplex](http://nodejs.org/api/stream.html#stream_class_stream_duplex) class.
  *
+ * @constructs Sharp
+ *
+ * @emits Sharp#info
+ * @emits Sharp#warning
+ *
  * @example
  * sharp('input.jpg')
  *   .resize(300, 200)
@@ -81,30 +86,31 @@ const debuglog = util.debuglog('sharp');
  * .toBuffer()
  * .then( ... );
  *
- * @param {(Buffer|String)} [input] - if present, can be
+ * @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 filesystem path to an JPEG, PNG, WebP, GIF, SVG or TIFF image file.
  *  JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data can be streamed into the object when not present.
  * @param {Object} [options] - if present, is an Object with optional attributes.
- * @param {Boolean} [options.failOnError=true] - by default halt processing and raise an error when loading invalid images.
+ * @param {boolean} [options.failOnError=true] - by default halt processing and raise an error when loading invalid images.
  *  Set this flag to `false` if you'd rather apply a "best effort" to decode images, even if the data is corrupt or invalid.
- * @param {Number|Boolean} [options.limitInputPixels=268402689] - Do not process input images where the number of pixels
+ * @param {number|boolean} [options.limitInputPixels=268402689] - Do not process input images where the number of pixels
  *  (width x height) exceeds this limit. Assumes image dimensions contained in the input metadata can be trusted.
  *  An integral Number of pixels, zero or false to remove limit, true to use default limit of 268402689 (0x3FFF x 0x3FFF).
- * @param {Boolean} [options.sequentialRead=false] - Set this to `true` to use sequential rather than random access where possible.
+ * @param {boolean} [options.sequentialRead=false] - Set this to `true` to use sequential rather than random access where possible.
  *  This can reduce memory usage and might improve performance on some systems.
- * @param {Number} [options.density=72] - number representing the DPI for vector images.
+ * @param {number} [options.density=72] - number representing the DPI for vector images.
- * @param {Number} [options.pages=1] - number of pages to extract for multi-page input (GIF, TIFF, PDF), use -1 for all pages.
+ * @param {number} [options.pages=1] - number of pages to extract for multi-page input (GIF, TIFF, PDF), use -1 for all pages.
- * @param {Number} [options.page=0] - page number to start extracting from for multi-page input (GIF, TIFF, PDF), zero based.
+ * @param {number} [options.page=0] - page number to start extracting from for multi-page input (GIF, TIFF, PDF), zero based.
+ * @param {number} [options.level=0] - level to extract from a multi-level input (OpenSlide), zero based.
  * @param {Object} [options.raw] - describes raw pixel input image data. See `raw()` for pixel ordering.
- * @param {Number} [options.raw.width]
+ * @param {number} [options.raw.width]
- * @param {Number} [options.raw.height]
+ * @param {number} [options.raw.height]
- * @param {Number} [options.raw.channels] - 1-4
+ * @param {number} [options.raw.channels] - 1-4
  * @param {Object} [options.create] - describes a new image to be created.
- * @param {Number} [options.create.width]
+ * @param {number} [options.create.width]
- * @param {Number} [options.create.height]
+ * @param {number} [options.create.height]
- * @param {Number} [options.create.channels] - 3-4
+ * @param {number} [options.create.channels] - 3-4
- * @param {String|Object} [options.create.background] - parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
+ * @param {string|Object} [options.create.background] - parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha.
  * @returns {Sharp}
  * @throws {Error} Invalid parameters
  */
@@ -229,7 +235,10 @@ const Sharp = function (input, options) {
     linearA: 1,
     linearB: 0,
     // Function to notify of libvips warnings
-    debuglog: debuglog,
+    debuglog: warning => {
+      this.emit('warning', warning);
+      debuglog(warning);
+    },
     // Function to notify of queue length changes
     queueListener: function (queueLength) {
       Sharp.queue.emit('change', queueLength);

lib/input.js

@@ -113,6 +113,14 @@ function _createInputDescriptor (input, inputOptions, containerOptions) {
         throw is.invalidParameterError('page', 'integer between 0 and 100000', inputOptions.page);
       }
     }
+    // Multi-level input (OpenSlide)
+    if (is.defined(inputOptions.level)) {
+      if (is.integer(inputOptions.level) && is.inRange(inputOptions.level, 0, 256)) {
+        inputDescriptor.level = inputOptions.level;
+      } else {
+        throw is.invalidParameterError('level', 'integer between 0 and 256', inputOptions.level);
+      }
+    }
     // Create new image
     if (is.defined(inputOptions.create)) {
       if (
@@ -208,6 +216,7 @@ function _isStreamInput () {
  * - `loop`: Number of times to loop an animated image, zero refers to a continuous loop.
  * - `delay`: Delay in ms between each page in an animated image, provided as an array of integers.
  * - `pagePrimary`: Number of the primary page in a HEIF image
+ * - `levels`: Details of each level in a multi-level image provided as an array of objects, requires libvips compiled with support for OpenSlide
  * - `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
@@ -290,6 +299,7 @@ function metadata (callback) {
  *     - `maxY` (y-coordinate of one of the pixel where the maximum lies)
  * - `isOpaque`: Is the image fully opaque? Will be `true` if the image has no alpha channel or if every pixel is fully opaque.
  * - `entropy`: Histogram-based estimation of greyscale entropy, discarding alpha channel if any (experimental)
+ * - `sharpness`: Estimation of greyscale sharpness based on the standard deviation of a Laplacian convolution, discarding alpha channel if any (experimental)
  *
  * @example
  * const image = sharp(inputJpg);
@@ -299,6 +309,9 @@ function metadata (callback) {
  *      // stats contains the channel-wise statistics array and the isOpaque value
  *   });
  *
+ * @example
+ * const { entropy, sharpness } = await sharp(input).stats();
+ *
  * @param {Function} [callback] - called with the arguments `(err, stats)`
  * @returns {Promise<Object>}
  */

lib/is.js

@@ -21,7 +21,7 @@ const object = function (val) {
  * @private
  */
 const plainObject = function (val) {
-  return object(val) && Object.prototype.toString.call(val) === '[object Object]';
+  return Object.prototype.toString.call(val) === '[object Object]';
 };
 
 /**
@@ -45,7 +45,7 @@ const bool = function (val) {
  * @private
  */
 const buffer = function (val) {
-  return object(val) && val instanceof Buffer;
+  return val instanceof Buffer;
 };
 
 /**
@@ -69,7 +69,7 @@ const number = function (val) {
  * @private
  */
 const integer = function (val) {
-  return number(val) && val % 1 === 0;
+  return Number.isInteger(val);
 };
 
 /**
@@ -85,7 +85,7 @@ const inRange = function (val, min, max) {
  * @private
  */
 const inArray = function (val, list) {
-  return list.indexOf(val) !== -1;
+  return list.includes(val);
 };
 
 /**

lib/libvips.js

@@ -65,7 +65,7 @@ const hasVendoredLibvips = function () {
     if (currentPlatformId === vendorPlatformId) {
       return true;
     } else {
-      throw new Error(`'${vendorPlatformId}' binaries cannot be used on the '${currentPlatformId}' platform. Please remove the 'node_modules/sharp/vendor' directory and run 'npm install'.`);
+      throw new Error(`'${vendorPlatformId}' binaries cannot be used on the '${currentPlatformId}' platform. Please remove the 'node_modules/sharp' directory and run 'npm install' on the '${currentPlatformId}' platform.`);
     }
   } else {
     return false;

lib/output.js

@@ -173,6 +173,8 @@ function toFormat (format, options) {
 /**
  * Use these JPEG options for output image.
  *
+ * Some of these options require the use of a globally-installed libvips compiled with support for mozjpeg.
+ *
  * @example
  * // Convert any input to very high quality JPEG output
  * const data = await sharp(input)
@@ -186,14 +188,14 @@ function toFormat (format, 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'] - for quality < 90, set to '4:4:4' to prevent chroma subsampling otherwise defaults to '4:2:0' (use chroma subsampling); for quality >= 90 chroma is never subsampled
+ * @param {boolean} [options.optimiseCoding=true] - optimise Huffman coding tables
+ * @param {boolean} [options.optimizeCoding=true] - alternative spelling of optimiseCoding
  * @param {boolean} [options.trellisQuantisation=false] - apply trellis quantisation, requires libvips compiled with support for mozjpeg
  * @param {boolean} [options.overshootDeringing=false] - apply overshoot deringing, requires libvips compiled with support for mozjpeg
  * @param {boolean} [options.optimiseScans=false] - optimise progressive scans, forces progressive, requires libvips compiled with support for mozjpeg
- * @param {boolean} [options.optimizeScans=false] - alternative spelling of optimiseScans
+ * @param {boolean} [options.optimizeScans=false] - alternative spelling of optimiseScans, requires libvips compiled with support for mozjpeg
- * @param {boolean} [options.optimiseCoding=true] - optimise Huffman coding tables
- * @param {boolean} [options.optimizeCoding=true] - alternative spelling of optimiseCoding
  * @param {number} [options.quantisationTable=0] - quantization table to use, integer 0-8, requires libvips compiled with support for mozjpeg
- * @param {number} [options.quantizationTable=0] - alternative spelling of quantisationTable
+ * @param {number} [options.quantizationTable=0] - alternative spelling of quantisationTable, requires libvips compiled with support for mozjpeg
  * @param {boolean} [options.force=true] - force JPEG output, otherwise attempt to use input format
  * @returns {Sharp}
  * @throws {Error} Invalid options
@@ -253,6 +255,8 @@ function jpeg (options) {
  * PNG output is always full colour at 8 or 16 bits per pixel.
  * Indexed PNG input at 1, 2 or 4 bits per pixel is converted to 8 bits per pixel.
  *
+ * Some of these options require the use of a globally-installed libvips compiled with support for libimagequant (GPL).
+ *
  * @example
  * // Convert any input to PNG output
  * const data = await sharp(input)
@@ -264,10 +268,10 @@ function jpeg (options) {
  * @param {number} [options.compressionLevel=9] - zlib compression level, 0-9
  * @param {boolean} [options.adaptiveFiltering=false] - use adaptive row filtering
  * @param {boolean} [options.palette=false] - quantise to a palette-based image with alpha transparency support, requires libvips compiled with support for libimagequant
- * @param {number} [options.quality=100] - use the lowest number of colours needed to achieve given quality, requires libvips compiled with support for libimagequant
+ * @param {number} [options.quality=100] - use the lowest number of colours needed to achieve given quality, sets `palette` to `true`, requires libvips compiled with support for libimagequant
- * @param {number} [options.colours=256] - maximum number of palette entries, requires libvips compiled with support for libimagequant
+ * @param {number} [options.colours=256] - maximum number of palette entries, sets `palette` to `true`, requires libvips compiled with support for libimagequant
- * @param {number} [options.colors=256] - alternative spelling of `options.colours`, requires libvips compiled with support for libimagequant
+ * @param {number} [options.colors=256] - alternative spelling of `options.colours`, sets `palette` to `true`, requires libvips compiled with support for libimagequant
- * @param {number} [options.dither=1.0] - level of Floyd-Steinberg error diffusion, requires libvips compiled with support for libimagequant
+ * @param {number} [options.dither=1.0] - level of Floyd-Steinberg error diffusion, sets `palette` to `true`, requires libvips compiled with support for libimagequant
  * @param {boolean} [options.force=true] - force PNG output, otherwise attempt to use input format
  * @returns {Sharp}
  * @throws {Error} Invalid options
@@ -289,28 +293,30 @@ function png (options) {
     }
     if (is.defined(options.palette)) {
       this._setBooleanOption('pngPalette', options.palette);
-      if (this.options.pngPalette) {
+    } else if (is.defined(options.quality) || is.defined(options.colours || options.colors) || is.defined(options.dither)) {
-        if (is.defined(options.quality)) {
+      this._setBooleanOption('pngPalette', true);
-          if (is.integer(options.quality) && is.inRange(options.quality, 0, 100)) {
+    }
-            this.options.pngQuality = options.quality;
+    if (this.options.pngPalette) {
-          } else {
+      if (is.defined(options.quality)) {
-            throw is.invalidParameterError('quality', 'integer between 0 and 100', options.quality);
+        if (is.integer(options.quality) && is.inRange(options.quality, 0, 100)) {
-          }
+          this.options.pngQuality = options.quality;
+        } else {
+          throw is.invalidParameterError('quality', 'integer between 0 and 100', options.quality);
         }
-        const colours = options.colours || options.colors;
+      }
-        if (is.defined(colours)) {
+      const colours = options.colours || options.colors;
-          if (is.integer(colours) && is.inRange(colours, 2, 256)) {
+      if (is.defined(colours)) {
-            this.options.pngColours = colours;
+        if (is.integer(colours) && is.inRange(colours, 2, 256)) {
-          } else {
+          this.options.pngColours = colours;
-            throw is.invalidParameterError('colours', 'integer between 2 and 256', colours);
+        } else {
-          }
+          throw is.invalidParameterError('colours', 'integer between 2 and 256', colours);
         }
-        if (is.defined(options.dither)) {
+      }
-          if (is.number(options.dither) && is.inRange(options.dither, 0, 1)) {
+      if (is.defined(options.dither)) {
-            this.options.pngDither = options.dither;
+        if (is.number(options.dither) && is.inRange(options.dither, 0, 1)) {
-          } else {
+          this.options.pngDither = options.dither;
-            throw is.invalidParameterError('dither', 'number between 0.0 and 1.0', options.dither);
+        } else {
-          }
+          throw is.invalidParameterError('dither', 'number between 0.0 and 1.0', options.dither);
         }
       }
     }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "sharp",
   "description": "High performance Node.js image processing, the fastest module to resize JPEG, PNG, WebP and TIFF images",
-  "version": "0.25.3",
+  "version": "0.25.4",
   "author": "Lovell Fuller <npm@lovell.info>",
   "homepage": "https://github.com/lovell/sharp",
   "contributors": [
@@ -66,7 +66,8 @@
     "Paul Neave <paul.neave@gmail.com>",
     "Brendan Kennedy <brenwken@gmail.com>",
     "Brychan Bennett-Odlum <git@brychan.io>",
-    "Edward Silverton <e.silverton@gmail.com>"
+    "Edward Silverton <e.silverton@gmail.com>",
+    "Roman Malieiev <aromaleev@gmail.com>"
   ],
   "scripts": {
     "install": "(node install/libvips && node install/dll-copy && prebuild-install --runtime=napi) || (node-gyp rebuild && node install/dll-copy)",
@@ -112,7 +113,7 @@
     "detect-libc": "^1.0.3",
     "node-addon-api": "^3.0.0",
     "npmlog": "^4.1.2",
-    "prebuild-install": "^5.3.3",
+    "prebuild-install": "^5.3.4",
     "semver": "^7.3.2",
     "simple-get": "^4.0.0",
     "tar": "^6.0.2",
@@ -122,13 +123,13 @@
     "async": "^3.2.0",
     "cc": "^2.0.1",
     "decompress-zip": "^0.3.2",
-    "documentation": "^13.0.0",
+    "documentation": "^13.0.1",
     "exif-reader": "^1.0.3",
     "icc": "^1.0.0",
     "license-checker": "^25.0.1",
-    "mocha": "^7.1.2",
+    "mocha": "^8.0.1",
     "mock-fs": "^4.12.0",
-    "nyc": "^15.0.1",
+    "nyc": "^15.1.0",
     "prebuild": "^10.0.0",
     "prebuild-ci": "^3.1.0",
     "rimraf": "^3.0.2",

src/common.cc

@@ -88,6 +88,10 @@ namespace sharp {
     if (HasAttr(input, "page")) {
       descriptor->page = AttrAsUint32(input, "page");
     }
+    // Multi-level input (OpenSlide)
+    if (HasAttr(input, "level")) {
+      descriptor->level = AttrAsUint32(input, "level");
+    }
     // Create new image
     if (HasAttr(input, "createChannels")) {
       descriptor->createChannels = AttrAsUint32(input, "createChannels");
@@ -292,6 +296,9 @@ namespace sharp {
               option->set("n", descriptor->pages);
               option->set("page", descriptor->page);
             }
+            if (imageType == ImageType::OPENSLIDE) {
+              option->set("level", descriptor->level);
+            }
             image = VImage::new_from_buffer(descriptor->buffer, descriptor->bufferLength, nullptr, option);
             if (imageType == ImageType::SVG || imageType == ImageType::PDF || imageType == ImageType::MAGICK) {
               image = SetDensity(image, descriptor->density);
@@ -341,6 +348,9 @@ namespace sharp {
               option->set("n", descriptor->pages);
               option->set("page", descriptor->page);
             }
+            if (imageType == ImageType::OPENSLIDE) {
+              option->set("level", descriptor->level);
+            }
             image = VImage::new_from_file(descriptor->file.data(), option);
             if (imageType == ImageType::SVG || imageType == ImageType::PDF || imageType == ImageType::MAGICK) {
               image = SetDensity(image, descriptor->density);

src/common.h

@@ -57,6 +57,7 @@ namespace sharp {
     int rawHeight;
     int pages;
     int page;
+    int level;
     int createChannels;
     int createWidth;
     int createHeight;
@@ -75,6 +76,7 @@ namespace sharp {
       rawHeight(0),
       pages(1),
       page(0),
+      level(0),
       createChannels(0),
       createWidth(0),
       createHeight(0),

src/metadata.cc

@@ -74,6 +74,15 @@ class MetadataWorker : public Napi::AsyncWorker {
       if (image.get_typeof("heif-primary") == G_TYPE_INT) {
         baton->pagePrimary = image.get_int("heif-primary");
       }
+      if (image.get_typeof("openslide.level-count") == VIPS_TYPE_REF_STRING) {
+        int const levels = std::stoi(image.get_string("openslide.level-count"));
+        for (int l = 0; l < levels; l++) {
+          std::string prefix = "openslide.level[" + std::to_string(l) + "].";
+          int const width = std::stoi(image.get_string((prefix + "width").data()));
+          int const height = std::stoi(image.get_string((prefix + "height").data()));
+          baton->levels.push_back(std::pair<int, int>(width, height));
+        }
+      }
       baton->hasProfile = sharp::HasProfile(image);
       // Derived attributes
       baton->hasAlpha = sharp::HasAlpha(image);
@@ -177,6 +186,17 @@ class MetadataWorker : public Napi::AsyncWorker {
       if (baton->pagePrimary > -1) {
         info.Set("pagePrimary", baton->pagePrimary);
       }
+      if (!baton->levels.empty()) {
+        int i = 0;
+        Napi::Array levels = Napi::Array::New(env, static_cast<size_t>(baton->levels.size()));
+        for (std::pair<int, int> const l : baton->levels) {
+          Napi::Object level = Napi::Object::New(env);
+          level.Set("width", l.first);
+          level.Set("height", l.second);
+          levels.Set(i++, level);
+        }
+        info.Set("levels", levels);
+      }
       info.Set("hasProfile", baton->hasProfile);
       info.Set("hasAlpha", baton->hasAlpha);
       if (baton->orientation > 0) {

src/metadata.h

@@ -39,6 +39,7 @@ struct MetadataBaton {
   int loop;
   std::vector<int> delay;
   int pagePrimary;
+  std::vector<std::pair<int, int>> levels;
   bool hasProfile;
   bool hasAlpha;
   int orientation;

src/pipeline.cc

@@ -645,8 +645,12 @@ class PipelineWorker : public Napi::AsyncWorker {
       // Extract an image channel (aka vips band)
       if (baton->extractChannel > -1) {
         if (baton->extractChannel >= image.bands()) {
-          (baton->err).append("Cannot extract channel from image. Too few channels in image.");
+          if (baton->extractChannel == 3 && sharp::HasAlpha(image)) {
-          return Error();
+            baton->extractChannel = image.bands() - 1;
+          } else {
+            (baton->err).append("Cannot extract channel from image. Too few channels in image.");
+            return Error();
+          }
         }
         VipsInterpretation const interpretation = sharp::Is16Bit(image.interpretation())
           ? VIPS_INTERPRETATION_GREY16

src/stats.cc

@@ -75,8 +75,17 @@ class StatsWorker : public Napi::AsyncWorker {
             baton->isOpaque = false;
           }
         }
+        // Convert to greyscale
+        vips::VImage greyscale = image.colourspace(VIPS_INTERPRETATION_B_W)[0];
         // Estimate entropy via histogram of greyscale value frequency
-        baton->entropy = std::abs(image.colourspace(VIPS_INTERPRETATION_B_W)[0].hist_find().hist_entropy());
+        baton->entropy = std::abs(greyscale.hist_find().hist_entropy());
+        // Estimate sharpness via standard deviation of greyscale laplacian
+        VImage laplacian = VImage::new_matrixv(3, 3,
+          0.0,  1.0, 0.0,
+          1.0, -4.0, 1.0,
+          0.0,  1.0, 0.0);
+        laplacian.set("scale", 9.0);
+        baton->sharpness = greyscale.conv(laplacian).deviate();
       } catch (vips::VError const &err) {
         (baton->err).append(err.what());
       }
@@ -123,6 +132,7 @@ class StatsWorker : public Napi::AsyncWorker {
       info.Set("channels", channels);
       info.Set("isOpaque", baton->isOpaque);
       info.Set("entropy", baton->entropy);
+      info.Set("sharpness", baton->sharpness);
       Callback().MakeCallback(Receiver().Value(), { env.Null(), info });
     } else {
       Callback().MakeCallback(Receiver().Value(), { Napi::Error::New(env, baton->err).Value() });

src/stats.h

@@ -47,13 +47,15 @@ struct StatsBaton {
   std::vector<ChannelStats> channelStats;
   bool isOpaque;
   double entropy;
+  double sharpness;
 
   std::string err;
 
   StatsBaton():
     input(nullptr),
     isOpaque(true),
-    entropy(0.0)
+    entropy(0.0),
+    sharpness(0.0)
     {}
 };
 

test/unit/extractChannel.js

@@ -80,6 +80,19 @@ describe('Image channel extraction', function () {
       });
   });
 
+  it('Alpha from 2-channel input', function (done) {
+    const output = fixtures.path('output.extract-alpha-2-channel.png');
+    sharp(fixtures.inputPngWithGreyAlpha)
+      .extractChannel('alpha')
+      .toColourspace('b-w')
+      .toFile(output, function (err, info) {
+        if (err) throw err;
+        assert.strictEqual(1, info.channels);
+        fixtures.assertMaxColourDistance(output, fixtures.expected('extract-alpha-2-channel.png'));
+        done();
+      });
+  });
+
   it('Invalid channel number', function () {
     assert.throws(function () {
       sharp(fixtures.inputJpg)

test/unit/failOnError.js

@@ -19,11 +19,17 @@ describe('failOnError', function () {
       });
   });
 
-  it('handles truncated PNG', function (done) {
+  it('handles truncated PNG, emits warnings', function (done) {
+    let isWarningEmitted = false;
     sharp(fixtures.inputPngTruncated, { failOnError: false })
+      .on('warning', function (warning) {
+        assert.strictEqual('not enough data', warning);
+        isWarningEmitted = true;
+      })
       .resize(320, 240)
       .toBuffer(function (err, data, info) {
         if (err) throw err;
+        assert.strictEqual(true, isWarningEmitted);
         assert.strictEqual('png', info.format);
         assert.strictEqual(320, info.width);
         assert.strictEqual(240, info.height);

test/unit/io.js

@@ -302,7 +302,7 @@ describe('Input/output', function () {
   });
 
   it('Fail when input is empty Buffer', function (done) {
-    if (process.platform === 'freebsd') return this.skip(); // can be removed with libvips 8.10.0+
+    if (sharp.format.magick.input.buffer) return this.skip(); // can be removed with libvips 8.10.0+
     sharp(Buffer.alloc(0)).toBuffer().then(function () {
       assert(false);
       done();
@@ -659,6 +659,19 @@ describe('Input/output', function () {
         sharp({ pages: '1' });
       }, /Expected integer between -1 and 100000 for pages but received 1 of type string/);
     });
+    it('Valid level property', function () {
+      sharp({ level: 1 });
+    });
+    it('Invalid level property (string) throws', function () {
+      assert.throws(function () {
+        sharp({ level: '1' });
+      }, /Expected integer between 0 and 256 for level but received 1 of type string/);
+    });
+    it('Invalid level property (negative) throws', function () {
+      assert.throws(function () {
+        sharp({ level: -1 });
+      }, /Expected integer between 0 and 256 for level but received -1 of type number/);
+    });
   });
 
   describe('create new image', function () {

test/unit/metadata.js

@@ -19,7 +19,7 @@ describe('Image metadata', function () {
       assert.strictEqual('srgb', metadata.space);
       assert.strictEqual(3, metadata.channels);
       assert.strictEqual('uchar', metadata.depth);
-      assert.strictEqual('undefined', typeof metadata.density);
+      assert.strictEqual(true, ['undefined', 'number'].includes(typeof metadata.density));
       assert.strictEqual('4:2:0', metadata.chromaSubsampling);
       assert.strictEqual(false, metadata.isProgressive);
       assert.strictEqual(false, metadata.hasProfile);
@@ -311,7 +311,7 @@ describe('Image metadata', function () {
       assert.strictEqual('srgb', metadata.space);
       assert.strictEqual(3, metadata.channels);
       assert.strictEqual('uchar', metadata.depth);
-      assert.strictEqual('undefined', typeof metadata.density);
+      assert.strictEqual(true, ['undefined', 'number'].includes(typeof metadata.density));
       assert.strictEqual('4:2:0', metadata.chromaSubsampling);
       assert.strictEqual(false, metadata.isProgressive);
       assert.strictEqual(false, metadata.hasProfile);
@@ -343,7 +343,7 @@ describe('Image metadata', function () {
       assert.strictEqual('srgb', metadata.space);
       assert.strictEqual(3, metadata.channels);
       assert.strictEqual('uchar', metadata.depth);
-      assert.strictEqual('undefined', typeof metadata.density);
+      assert.strictEqual(true, ['undefined', 'number'].includes(typeof metadata.density));
       assert.strictEqual('4:2:0', metadata.chromaSubsampling);
       assert.strictEqual(false, metadata.isProgressive);
       assert.strictEqual(false, metadata.hasProfile);
@@ -381,7 +381,7 @@ describe('Image metadata', function () {
       assert.strictEqual('srgb', metadata.space);
       assert.strictEqual(3, metadata.channels);
       assert.strictEqual('uchar', metadata.depth);
-      assert.strictEqual('undefined', typeof metadata.density);
+      assert.strictEqual(true, ['undefined', 'number'].includes(typeof metadata.density));
       assert.strictEqual('4:2:0', metadata.chromaSubsampling);
       assert.strictEqual(false, metadata.isProgressive);
       assert.strictEqual(false, metadata.hasProfile);
@@ -405,7 +405,7 @@ describe('Image metadata', function () {
       assert.strictEqual('srgb', metadata.space);
       assert.strictEqual(3, metadata.channels);
       assert.strictEqual('uchar', metadata.depth);
-      assert.strictEqual('undefined', typeof metadata.density);
+      assert.strictEqual(true, ['undefined', 'number'].includes(typeof metadata.density));
       assert.strictEqual('4:2:0', metadata.chromaSubsampling);
       assert.strictEqual(false, metadata.isProgressive);
       assert.strictEqual(false, metadata.hasProfile);

test/unit/png.js

@@ -127,8 +127,8 @@ describe('PNG', function () {
   it('Valid PNG libimagequant quality value produces image of same size or smaller', function () {
     const inputPngBuffer = fs.readFileSync(fixtures.inputPng);
     return Promise.all([
-      sharp(inputPngBuffer).resize(10).png({ palette: true, quality: 80 }).toBuffer(),
+      sharp(inputPngBuffer).resize(10).png({ quality: 80 }).toBuffer(),
-      sharp(inputPngBuffer).resize(10).png({ palette: true, quality: 100 }).toBuffer()
+      sharp(inputPngBuffer).resize(10).png({ quality: 100 }).toBuffer()
     ]).then(function (data) {
       assert.strictEqual(true, data[0].length <= data[1].length);
     });
@@ -136,15 +136,15 @@ describe('PNG', function () {
 
   it('Invalid PNG libimagequant quality value throws error', function () {
     assert.throws(function () {
-      sharp().png({ palette: true, quality: 101 });
+      sharp().png({ quality: 101 });
     });
   });
 
   it('Valid PNG libimagequant colours value produces image of same size or smaller', function () {
     const inputPngBuffer = fs.readFileSync(fixtures.inputPng);
     return Promise.all([
-      sharp(inputPngBuffer).resize(10).png({ palette: true, colours: 100 }).toBuffer(),
+      sharp(inputPngBuffer).resize(10).png({ colours: 100 }).toBuffer(),
-      sharp(inputPngBuffer).resize(10).png({ palette: true, colours: 200 }).toBuffer()
+      sharp(inputPngBuffer).resize(10).png({ colours: 200 }).toBuffer()
     ]).then(function (data) {
       assert.strictEqual(true, data[0].length <= data[1].length);
     });
@@ -152,21 +152,21 @@ describe('PNG', function () {
 
   it('Invalid PNG libimagequant colours value throws error', function () {
     assert.throws(function () {
-      sharp().png({ palette: true, colours: -1 });
+      sharp().png({ colours: -1 });
     });
   });
 
   it('Invalid PNG libimagequant colors value throws error', function () {
     assert.throws(function () {
-      sharp().png({ palette: true, colors: 0.1 });
+      sharp().png({ colors: 0.1 });
     });
   });
 
   it('Valid PNG libimagequant dither value produces image of same size or smaller', function () {
     const inputPngBuffer = fs.readFileSync(fixtures.inputPng);
     return Promise.all([
-      sharp(inputPngBuffer).resize(10).png({ palette: true, dither: 0.1 }).toBuffer(),
+      sharp(inputPngBuffer).resize(10).png({ dither: 0.1 }).toBuffer(),
-      sharp(inputPngBuffer).resize(10).png({ palette: true, dither: 0.9 }).toBuffer()
+      sharp(inputPngBuffer).resize(10).png({ dither: 0.9 }).toBuffer()
     ]).then(function (data) {
       assert.strictEqual(true, data[0].length <= data[1].length);
     });
@@ -174,7 +174,7 @@ describe('PNG', function () {
 
   it('Invalid PNG libimagequant dither value throws error', function () {
     assert.throws(function () {
-      sharp().png({ palette: true, dither: 'fail' });
+      sharp().png({ dither: 'fail' });
     });
   });
 });

test/unit/stats.js

@@ -25,6 +25,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(true, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.319914765248541));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 0.7883011147075762));
 
       // red channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -84,6 +85,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(true, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 0.3409031108021736));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 9.111356137722868));
 
       // red channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -110,6 +112,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(false, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 0.06778064835816622));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 2.522916068931278));
 
       // red channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -185,6 +188,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(false, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 0));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 0));
 
       // alpha channel
       assert.strictEqual(0, stats.channels[3].min);
@@ -212,6 +216,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(true, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 0.3851250782608986));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 10.312521863719589));
 
       // red channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -239,6 +244,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(true, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.51758075132966));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 9.959951636662941));
 
       // red channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -298,6 +304,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(true, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 6.087309412541799));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 2.9250574456255682));
 
       // red channel
       assert.strictEqual(35, stats.channels[0].min);
@@ -357,6 +364,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(false, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 1));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 15.870619016486861));
 
       // gray channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -410,6 +418,7 @@ describe('Image Stats', function () {
 
       assert.strictEqual(true, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.319914765248541));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 0.788301114707569));
 
       // red channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -472,6 +481,7 @@ describe('Image Stats', function () {
     return pipeline.stats().then(function (stats) {
       assert.strictEqual(true, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.319914765248541));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 0.788301114707569));
 
       // red channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -529,6 +539,7 @@ describe('Image Stats', function () {
     return sharp(fixtures.inputJpg).stats().then(function (stats) {
       assert.strictEqual(true, stats.isOpaque);
       assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.319914765248541));
+      assert.strictEqual(true, isInAcceptableRange(stats.sharpness, 0.788301114707569));
 
       // red channel
       assert.strictEqual(0, stats.channels[0].min);
@@ -582,6 +593,18 @@ describe('Image Stats', function () {
     });
   });
 
+  it('Blurred image has lower sharpness than original', () => {
+    const original = sharp(fixtures.inputJpg).stats();
+    const blurred = sharp(fixtures.inputJpg).blur().toBuffer().then(blur => sharp(blur).stats());
+
+    return Promise
+      .all([original, blurred])
+      .then(([original, blurred]) => {
+        assert.strictEqual(true, isInAcceptableRange(original.sharpness, 0.7883011147075476));
+        assert.strictEqual(true, isInAcceptableRange(blurred.sharpness, 0.4791559805997398));
+      });
+  });
+
   it('File input with corrupt header fails gracefully', function (done) {
     sharp(fixtures.inputJpgWithCorruptHeader)
       .stats(function (err) {