Release v0.23.3

Improve C++ linting, move exceptions inline
Add FreeBSD to CI via Cirrus #1953
2026-02-04 05:36:18 +01:00 · 2019-11-17 15:42:07 +00:00 · 2019-11-14 22:06:38 +00:00 · 2019-11-14 21:55:20 +00:00 · 2019-11-14 13:18:14 +00:00 · 2019-11-14 11:32:49 +00:00
62 changed files with 1159 additions and 678 deletions
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -0,0 +1,13 @@
+freebsd_instance:
+  image_family: freebsd-12-0
+
+task:
+  prerequisites_script:
+    - sed -i '' 's/quarterly/latest/g' /etc/pkg/FreeBSD.conf
+    - pkg update -f
+    - pkg upgrade -y
+    - pkg install -y pkgconf vips libnghttp2 node npm
+  install_script:
+    - npm install --unsafe-perm
+  test_script:
+    - npm test
--- a/.github/FUNDING.yml
+++ b/.github/FUNDING.yml
@@ -0,0 +1 @@
+open_collective: libvips
--- a/.github/ISSUE_TEMPLATE/installation.md
+++ b/.github/ISSUE_TEMPLATE/installation.md
@@ -1,16 +1,18 @@
 ---
 name: Installation
-about: For help if something went wrong installing sharp
+about: Something went wrong **installing** sharp
 title: ''
-labels: ''
+labels: installation
 assignees: ''

 ---

-What is the output of running `npm install --verbose sharp`?
-
-What is the output of running `npx envinfo --binaries --languages --system --utilities`?
+Did you see the [documentation relating to installation](https://sharp.pixelplumbing.com/en/stable/install/)?

 Have you ensured the platform and version of Node.js used for `npm install` is the same as the platform and version of Node.js used at runtime?

-If you're using `sudo npm install` have you tried with the `sudo npm install --unsafe-perm` flag?
+If you are installing as a `root` or `sudo` user, have you tried with the `npm install --unsafe-perm` flag?
+
+What is the complete output of running `npm install --verbose sharp`? Have you checked this output for useful error messages?
+
+What is the output of running `npx envinfo --binaries --languages --system --utilities`?
--- a/.github/ISSUE_TEMPLATE/possible-bug.md
+++ b/.github/ISSUE_TEMPLATE/possible-bug.md
@@ -1,12 +1,14 @@
 ---
 name: Possible bug
-about: Please provide steps to reproduce
+about: Something unexpected occurred **using** sharp
 title: ''
-labels: ''
+labels: triage
 assignees: ''

 ---

+<!-- If this issue relates to installation, please use https://github.com/lovell/sharp/issues/new?labels=installation&template=installation.md instead. -->
+
 What is the output of running `npx envinfo --binaries --languages --system --utilities`?

 What are the steps to reproduce?
--- a/.github/ISSUE_TEMPLATE/question.md
+++ b/.github/ISSUE_TEMPLATE/question.md
@@ -1,12 +1,14 @@
 ---
 name: Question
-about: For help with an existing feature
+about: For help understanding an existing feature
 title: ''
 labels: question
 assignees: ''

 ---

+<!-- If this issue relates to installation, please use https://github.com/lovell/sharp/issues/new?labels=installation&template=installation.md instead. -->
+
 What are you trying to achieve?

 Have you searched for similar questions?
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,4 @@ vendor
 .nyc_output
 .vscode/
 package-lock.json
+.idea
--- a/.npmignore
+++ b/.npmignore
@@ -1,16 +0,0 @@
-build
-node_modules
-coverage
-.editorconfig
-.gitattributes
-.gitignore
-test
-.travis.yml
-appveyor.yml
-mkdocs.yml
-docs/css/
-vendor
-.prebuildrc
-.nyc_output
-.github/
-.vscode/
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,6 +18,12 @@ matrix:
      sudo: false
      language: node_js
      node_js: "12"
+    - name: "Linux (glibc) - Node 13"
+      os: linux
+      dist: trusty
+      sudo: false
+      language: node_js
+      node_js: "13"
      after_success:
        - npm install coveralls
        - cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js
@@ -51,6 +57,16 @@ matrix:
        - sudo docker exec sharp apk add build-base git python2 --update-cache
      install: sudo docker exec sharp sh -c "npm install --unsafe-perm"
      script: sudo docker exec sharp sh -c "npm test"
+    - name: "Linux (musl) - Node 13"
+      os: linux
+      dist: trusty
+      sudo: true
+      language: minimal
+      before_install:
+        - sudo docker run -dit --name sharp --env CI --env PREBUILD_TOKEN --volume "${PWD}:/mnt/sharp" --workdir /mnt/sharp node:13.0-alpine
+        - sudo docker exec sharp apk add build-base git python2 --update-cache
+      install: sudo docker exec sharp sh -c "npm install --unsafe-perm"
+      script: sudo docker exec sharp sh -c "npm test"
    - name: "OS X - Node 8"
      os: osx
      osx_image: xcode9.2
@@ -66,3 +82,10 @@ matrix:
      osx_image: xcode9.2
      language: node_js
      node_js: "12"
+    - name: "OS X - Node 13"
+      os: osx
+      osx_image: xcode10
+      language: node_js
+      node_js: "13"
+cache:
+  npm: false
--- a/README.md
+++ b/README.md
@@ -11,7 +11,8 @@ is to convert large images in common formats to
 smaller, web-friendly JPEG, PNG and WebP images of varying dimensions.

 Resizing an image is typically 4x-5x faster than using the
-quickest ImageMagick and GraphicsMagick settings.
+quickest ImageMagick and GraphicsMagick settings
+due to its use of [libvips](https://github.com/libvips/libvips).

 Colour spaces, embedded ICC profiles and alpha transparency channels are all handled correctly.
 Lanczos resampling ensures quality is not sacrificed for speed.
@@ -20,7 +21,7 @@ As well as image resizing, operations such as
 rotation, extraction, compositing and gamma correction are available.

 Most modern 64-bit OS X, Windows and Linux systems running
-Node versions 8, 10 and 12
+Node versions 8, 10, 12 and 13
 do not require any additional install or runtime dependencies.

 ## Examples
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -7,6 +7,7 @@ environment:
  - nodejs_version: "8"
  - nodejs_version: "10"
  - nodejs_version: "12"
+  - nodejs_version: "13"
 install:
  - ps: Update-NodeJsInstallation (Get-NodeJsLatestBuild $env:nodejs_version) x64
  - npm install -g npm@6
--- a/binding.gyp
+++ b/binding.gyp
@@ -183,16 +183,22 @@
    },
    'configurations': {
      'Release': {
-        'cflags_cc': [
-          '-Wno-cast-function-type'
-        ],
-        'msvs_settings': {
-          'VCCLCompilerTool': {
-            'ExceptionHandling': 1
-          }
-        },
-        'msvs_disabled_warnings': [
-          4275
+        'conditions': [
+          ['OS == "linux"', {
+            'cflags_cc': [
+              '-Wno-cast-function-type'
+            ]
+          }],
+          ['OS == "win"', {
+            'msvs_settings': {
+              'VCCLCompilerTool': {
+                'ExceptionHandling': 1
+              }
+            },
+            'msvs_disabled_warnings': [
+              4275
+            ]
+          }]
        ]
      }
    },
--- a/docs/api-composite.md
+++ b/docs/api-composite.md
@@ -31,6 +31,7 @@ and [https://www.cairographics.org/operators/][2]
    -   `images[].top` **[Number][7]?** the pixel offset from the top edge.
    -   `images[].left` **[Number][7]?** the pixel offset from the left edge.
    -   `images[].tile` **[Boolean][9]** set to true to repeat the overlay image across the entire image with the given `gravity`. (optional, default `false`)
+    -   `images[].premultiplied` **[Boolean][9]** set to true to avoid premultipling the image below. Equivalent to the `--premultiplied` vips option. (optional, default `false`)
    -   `images[].density` **[Number][7]** number representing the DPI for vector overlay image. (optional, default `72`)
    -   `images[].raw` **[Object][4]?** describes overlay when using raw pixel data.
        -   `images[].raw.width` **[Number][7]?** 
--- a/docs/api-constructor.md
+++ b/docs/api-constructor.md
@@ -6,7 +6,7 @@

 -   `input` **([Buffer][1] \| [String][2])?** if present, can be
     a Buffer containing JPEG, PNG, WebP, GIF, SVG, TIFF or raw pixel image data, or
-     a String containing the path to an JPEG, PNG, WebP, GIF, SVG or TIFF image file.
+     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.failOnError` **[Boolean][4]** by default halt processing and raise an error when loading invalid images.
--- a/docs/api-output.md
+++ b/docs/api-output.md
@@ -8,12 +8,15 @@ If an explicit output format is not selected, it will be inferred from the exten
 with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
 Note that raw pixel data is only supported for buffer output.

+By default all metadata will be removed, which includes EXIF-based orientation.
+See [withMetadata][1] for control over this.
+
 A `Promise` is returned when `callback` is not provided.

 ### Parameters

-   `fileOut` **[String][1]** the path to write the image data to.
-   `callback` **[Function][2]?** called on completion with two arguments `(err, info)`.
+-   `fileOut` **[String][2]** the path to write the image data to.
+-   `callback` **[Function][3]?** called on completion with two arguments `(err, info)`.
    `info` contains the output image `format`, `size` (bytes), `width`, `height`,
    `channels` and `premultiplied` (indicating if premultiplication was used).
    When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
@@ -32,15 +35,19 @@ sharp(input)
  .catch(err => { ... });
 ```

-   Throws **[Error][3]** Invalid parameters
+-   Throws **[Error][4]** Invalid parameters

-Returns **[Promise][4]&lt;[Object][5]>** when no callback is provided
+Returns **[Promise][5]&lt;[Object][6]>** when no callback is provided

 ## toBuffer

 Write output to a Buffer.
 JPEG, PNG, WebP, TIFF and RAW output are supported.
-By default, the format will match the input image, except GIF and SVG input which become PNG output.
+
+If no explicit format is set, the output format will match the input image, except GIF and SVG input which become PNG output.
+
+By default all metadata will be removed, which includes EXIF-based orientation.
+See [withMetadata][1] for control over this.

 `callback`, if present, gets three arguments `(err, data, info)` where:

@@ -54,9 +61,9 @@ A `Promise` is returned when `callback` is not provided.

 ### Parameters

-   `options` **[Object][5]?** 
-    -   `options.resolveWithObject` **[Boolean][6]?** Resolve the Promise with an Object containing `data` and `info` properties instead of resolving only with `data`.
-   `callback` **[Function][2]?** 
+-   `options` **[Object][6]?** 
+    -   `options.resolveWithObject` **[Boolean][7]?** Resolve the Promise with an Object containing `data` and `info` properties instead of resolving only with `data`.
+-   `callback` **[Function][3]?** 

 ### Examples

@@ -79,7 +86,7 @@ sharp(input)
  .catch(err => { ... });
 ```

-Returns **[Promise][4]&lt;[Buffer][7]>** when no callback is provided
+Returns **[Promise][5]&lt;[Buffer][8]>** when no callback is provided

 ## withMetadata

@@ -89,8 +96,8 @@ This will also convert to and add a web-friendly sRGB ICC profile.

 ### Parameters

-   `options` **[Object][5]?** 
-    -   `options.orientation` **[Number][8]?** value between 1 and 8, used to update the EXIF `Orientation` tag.
+-   `options` **[Object][6]?** 
+    -   `options.orientation` **[Number][9]?** value between 1 and 8, used to update the EXIF `Orientation` tag.

 ### Examples

@@ -101,7 +108,7 @@ sharp('input.jpg')
  .then(info => { ... });
 ```

-   Throws **[Error][3]** Invalid parameters
+-   Throws **[Error][4]** Invalid parameters

 Returns **Sharp** 

@@ -111,19 +118,19 @@ Use these JPEG options for output image.

 ### Parameters

-   `options` **[Object][5]?** output options
-    -   `options.quality` **[Number][8]** quality, integer 1-100 (optional, default `80`)
-    -   `options.progressive` **[Boolean][6]** use progressive (interlace) scan (optional, default `false`)
-    -   `options.chromaSubsampling` **[String][1]** set to '4:4:4' to prevent chroma subsampling when quality &lt;= 90 (optional, default `'4:2:0'`)
-    -   `options.trellisQuantisation` **[Boolean][6]** apply trellis quantisation, requires libvips compiled with support for mozjpeg (optional, default `false`)
-    -   `options.overshootDeringing` **[Boolean][6]** apply overshoot deringing, requires libvips compiled with support for mozjpeg (optional, default `false`)
-    -   `options.optimiseScans` **[Boolean][6]** optimise progressive scans, forces progressive, requires libvips compiled with support for mozjpeg (optional, default `false`)
-    -   `options.optimizeScans` **[Boolean][6]** alternative spelling of optimiseScans (optional, default `false`)
-    -   `options.optimiseCoding` **[Boolean][6]** optimise Huffman coding tables (optional, default `true`)
-    -   `options.optimizeCoding` **[Boolean][6]** alternative spelling of optimiseCoding (optional, default `true`)
-    -   `options.quantisationTable` **[Number][8]** quantization table to use, integer 0-8, requires libvips compiled with support for mozjpeg (optional, default `0`)
-    -   `options.quantizationTable` **[Number][8]** alternative spelling of quantisationTable (optional, default `0`)
-    -   `options.force` **[Boolean][6]** force JPEG output, otherwise attempt to use input format (optional, default `true`)
+-   `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]** set to '4:4:4' to prevent chroma subsampling when quality &lt;= 90 (optional, default `'4:2:0'`)
+    -   `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.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.force` **[Boolean][7]** force JPEG output, otherwise attempt to use input format (optional, default `true`)

 ### Examples

@@ -137,7 +144,7 @@ const data = await sharp(input)
  .toBuffer();
 ```

-   Throws **[Error][3]** Invalid options
+-   Throws **[Error][4]** Invalid options

 Returns **Sharp** 

@@ -150,16 +157,16 @@ Indexed PNG input at 1, 2 or 4 bits per pixel is converted to 8 bits per pixel.

 ### Parameters

-   `options` **[Object][5]?** 
-    -   `options.progressive` **[Boolean][6]** use progressive (interlace) scan (optional, default `false`)
-    -   `options.compressionLevel` **[Number][8]** zlib compression level, 0-9 (optional, default `9`)
-    -   `options.adaptiveFiltering` **[Boolean][6]** use adaptive row filtering (optional, default `false`)
-    -   `options.palette` **[Boolean][6]** quantise to a palette-based image with alpha transparency support, requires libvips compiled with support for libimagequant (optional, default `false`)
-    -   `options.quality` **[Number][8]** use the lowest number of colours needed to achieve given quality, requires libvips compiled with support for libimagequant (optional, default `100`)
-    -   `options.colours` **[Number][8]** maximum number of palette entries, requires libvips compiled with support for libimagequant (optional, default `256`)
-    -   `options.colors` **[Number][8]** alternative spelling of `options.colours`, requires libvips compiled with support for libimagequant (optional, default `256`)
-    -   `options.dither` **[Number][8]** level of Floyd-Steinberg error diffusion, requires libvips compiled with support for libimagequant (optional, default `1.0`)
-    -   `options.force` **[Boolean][6]** force PNG output, otherwise attempt to use input format (optional, default `true`)
+-   `options` **[Object][6]?** 
+    -   `options.progressive` **[Boolean][7]** use progressive (interlace) scan (optional, default `false`)
+    -   `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.colours` **[Number][9]** maximum number of palette entries, 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.dither` **[Number][9]** level of Floyd-Steinberg error diffusion, 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

@@ -170,7 +177,7 @@ const data = await sharp(input)
  .toBuffer();
 ```

-   Throws **[Error][3]** Invalid options
+-   Throws **[Error][4]** Invalid options

 Returns **Sharp** 

@@ -180,14 +187,14 @@ Use these WebP options for output image.

 ### Parameters

-   `options` **[Object][5]?** output options
-    -   `options.quality` **[Number][8]** quality, integer 1-100 (optional, default `80`)
-    -   `options.alphaQuality` **[Number][8]** quality of alpha layer, integer 0-100 (optional, default `100`)
-    -   `options.lossless` **[Boolean][6]** use lossless compression mode (optional, default `false`)
-    -   `options.nearLossless` **[Boolean][6]** use near_lossless compression mode (optional, default `false`)
-    -   `options.smartSubsample` **[Boolean][6]** use high quality chroma subsampling (optional, default `false`)
-    -   `options.reductionEffort` **[Number][8]** level of CPU effort to reduce file size, integer 0-6 (optional, default `4`)
-    -   `options.force` **[Boolean][6]** force WebP output, otherwise attempt to use input format (optional, default `true`)
+-   `options` **[Object][6]?** output options
+    -   `options.quality` **[Number][9]** quality, integer 1-100 (optional, default `80`)
+    -   `options.alphaQuality` **[Number][9]** quality of alpha layer, integer 0-100 (optional, default `100`)
+    -   `options.lossless` **[Boolean][7]** use lossless compression mode (optional, default `false`)
+    -   `options.nearLossless` **[Boolean][7]** use near_lossless compression mode (optional, default `false`)
+    -   `options.smartSubsample` **[Boolean][7]** use high quality chroma subsampling (optional, default `false`)
+    -   `options.reductionEffort` **[Number][9]** level of CPU effort to reduce file size, integer 0-6 (optional, default `4`)
+    -   `options.force` **[Boolean][7]** force WebP output, otherwise attempt to use input format (optional, default `true`)

 ### Examples

@@ -198,7 +205,7 @@ const data = await sharp(input)
  .toBuffer();
 ```

-   Throws **[Error][3]** Invalid options
+-   Throws **[Error][4]** Invalid options

 Returns **Sharp** 

@@ -208,18 +215,18 @@ Use these TIFF options for output image.

 ### Parameters

-   `options` **[Object][5]?** output options
-    -   `options.quality` **[Number][8]** quality, integer 1-100 (optional, default `80`)
-    -   `options.force` **[Boolean][6]** force TIFF output, otherwise attempt to use input format (optional, default `true`)
-    -   `options.compression` **[Boolean][6]** compression options: lzw, deflate, jpeg, ccittfax4 (optional, default `'jpeg'`)
-    -   `options.predictor` **[Boolean][6]** compression predictor options: none, horizontal, float (optional, default `'horizontal'`)
-    -   `options.pyramid` **[Boolean][6]** write an image pyramid (optional, default `false`)
-    -   `options.tile` **[Boolean][6]** write a tiled tiff (optional, default `false`)
-    -   `options.tileWidth` **[Boolean][6]** horizontal tile size (optional, default `256`)
-    -   `options.tileHeight` **[Boolean][6]** vertical tile size (optional, default `256`)
-    -   `options.xres` **[Number][8]** horizontal resolution in pixels/mm (optional, default `1.0`)
-    -   `options.yres` **[Number][8]** vertical resolution in pixels/mm (optional, default `1.0`)
-    -   `options.squash` **[Boolean][6]** squash 8-bit images down to 1 bit (optional, default `false`)
+-   `options` **[Object][6]?** output options
+    -   `options.quality` **[Number][9]** quality, integer 1-100 (optional, default `80`)
+    -   `options.force` **[Boolean][7]** force TIFF output, otherwise attempt to use input format (optional, default `true`)
+    -   `options.compression` **[Boolean][7]** compression options: lzw, deflate, jpeg, ccittfax4 (optional, default `'jpeg'`)
+    -   `options.predictor` **[Boolean][7]** compression predictor options: none, horizontal, float (optional, default `'horizontal'`)
+    -   `options.pyramid` **[Boolean][7]** write an image pyramid (optional, default `false`)
+    -   `options.tile` **[Boolean][7]** write a tiled tiff (optional, default `false`)
+    -   `options.tileWidth` **[Boolean][7]** horizontal tile size (optional, default `256`)
+    -   `options.tileHeight` **[Boolean][7]** vertical tile size (optional, default `256`)
+    -   `options.xres` **[Number][9]** horizontal resolution in pixels/mm (optional, default `1.0`)
+    -   `options.yres` **[Number][9]** vertical resolution in pixels/mm (optional, default `1.0`)
+    -   `options.squash` **[Boolean][7]** squash 8-bit images down to 1 bit (optional, default `false`)

 ### Examples

@@ -234,7 +241,7 @@ sharp('input.svg')
  .then(info => { ... });
 ```

-   Throws **[Error][3]** Invalid options
+-   Throws **[Error][4]** Invalid options

 Returns **Sharp** 

@@ -251,13 +258,13 @@ Most versions of libheif support only the patent-encumbered HEVC compression for

 ### Parameters

-   `options` **[Object][5]?** output options
-    -   `options.quality` **[Number][8]** quality, integer 1-100 (optional, default `80`)
-    -   `options.compression` **[Boolean][6]** compression format: hevc, avc, jpeg, av1 (optional, default `'hevc'`)
-    -   `options.lossless` **[Boolean][6]** use lossless compression (optional, default `false`)
+-   `options` **[Object][6]?** output options
+    -   `options.quality` **[Number][9]** quality, integer 1-100 (optional, default `80`)
+    -   `options.compression` **[Boolean][7]** compression format: hevc, avc, jpeg, av1 (optional, default `'hevc'`)
+    -   `options.lossless` **[Boolean][7]** use lossless compression (optional, default `false`)


-   Throws **[Error][3]** Invalid options
+-   Throws **[Error][4]** Invalid options

 Returns **Sharp** 

@@ -282,8 +289,8 @@ Force output to a given format.

 ### Parameters

-   `format` **([String][1] \| [Object][5])** as a String or an Object with an 'id' attribute
-   `options` **[Object][5]** output options
+-   `format` **([String][2] \| [Object][6])** as a String or an Object with an 'id' attribute
+-   `options` **[Object][6]** output options

 ### Examples

@@ -294,7 +301,7 @@ const data = await sharp(input)
  .toBuffer();
 ```

-   Throws **[Error][3]** unsupported format or options
+-   Throws **[Error][4]** unsupported format or options

 Returns **Sharp** 

@@ -308,14 +315,15 @@ Warning: multiple sharp instances concurrently producing tile output can expose

 ### Parameters

-   `options` **[Object][5]?** 
-    -   `options.size` **[Number][8]** tile size in pixels, a value between 1 and 8192. (optional, default `256`)
-    -   `options.overlap` **[Number][8]** tile overlap in pixels, a value between 0 and 8192. (optional, default `0`)
-    -   `options.angle` **[Number][8]** tile angle of rotation, must be a multiple of 90. (optional, default `0`)
-    -   `options.depth` **[String][1]?** how deep to make the pyramid, possible values are `onepixel`, `onetile` or `one`, default based on layout.
-    -   `options.skipBlanks` **[Number][8]** threshold to skip tile generation, a value 0 - 255 for 8-bit images or 0 - 65535 for 16-bit images (optional, default `-1`)
-    -   `options.container` **[String][1]** tile container, with value `fs` (filesystem) or `zip` (compressed file). (optional, default `'fs'`)
-    -   `options.layout` **[String][1]** filesystem layout, possible values are `dz`, `zoomify` or `google`. (optional, default `'dz'`)
+-   `options` **[Object][6]?** 
+    -   `options.size` **[Number][9]** tile size in pixels, a value between 1 and 8192. (optional, default `256`)
+    -   `options.overlap` **[Number][9]** tile overlap in pixels, a value between 0 and 8192. (optional, default `0`)
+    -   `options.angle` **[Number][9]** tile angle of rotation, must be a multiple of 90. (optional, default `0`)
+    -   `options.background` **([String][2] \| [Object][6])** background colour, parsed by the [color][10] module, defaults to white without transparency. (optional, default `{r:255,g:255,b:255,alpha:1}`)
+    -   `options.depth` **[String][2]?** how deep to make the pyramid, possible values are `onepixel`, `onetile` or `one`, default based on layout.
+    -   `options.skipBlanks` **[Number][9]** threshold to skip tile generation, a value 0 - 255 for 8-bit images or 0 - 65535 for 16-bit images (optional, default `-1`)
+    -   `options.container` **[String][2]** tile container, with value `fs` (filesystem) or `zip` (compressed file). (optional, default `'fs'`)
+    -   `options.layout` **[String][2]** filesystem layout, possible values are `dz`, `zoomify` or `google`. (optional, default `'dz'`)

 ### Examples

@@ -331,22 +339,26 @@ sharp('input.tiff')
  });
 ```

-   Throws **[Error][3]** Invalid parameters
+-   Throws **[Error][4]** Invalid parameters

 Returns **Sharp** 

-[1]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+[1]: #withmetadata

-[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function
+[2]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String

-[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error
+[3]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/function

-[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise
+[4]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Error

-[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object
+[5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise

-[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+[6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object

-[7]: https://nodejs.org/api/buffer.html
+[7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean

-[8]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+[8]: https://nodejs.org/api/buffer.html
+
+[9]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+
+[10]: https://www.npmjs.org/package/color
--- a/docs/api-resize.md
+++ b/docs/api-resize.md
@@ -196,6 +196,8 @@ Returns **Sharp**
 ## trim

 Trim "boring" pixels from all edges that contain values similar to the top-left pixel.
+Images consisting entirely of a single colour will calculate "boring" using the alpha channel, if any.
+
 The `info` response Object will contain `trimOffsetLeft` and `trimOffsetTop` properties.

 ### Parameters
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -4,6 +4,54 @@

 Requires libvips v8.8.1.

+#### v0.23.3 - 17<sup>th</sup> November 2019
+
+* Ensure `trim` operation supports images contained in the alpha channel.
+  [#1597](https://github.com/lovell/sharp/issues/1597)
+
+* Ensure tile `overlap` option works as expected.
+  [#1921](https://github.com/lovell/sharp/pull/1921)
+  [@rustyguts](https://github.com/rustyguts)
+
+* Allow compilation on FreeBSD and variants (broken since v0.23.0)
+  [#1952](https://github.com/lovell/sharp/pull/1952)
+  [@pouya-eghbali](https://github.com/pouya-eghbali)
+
+* Ensure `modulate` and other colour-based operations can co-exist.
+  [#1958](https://github.com/lovell/sharp/issues/1958)
+
+#### v0.23.2 - 28<sup>th</sup> October 2019
+
+* Add `background` option to tile output operation.
+  [#1924](https://github.com/lovell/sharp/pull/1924)
+  [@neave](https://github.com/neave)
+
+* Add support for Node.js 13.
+  [#1932](https://github.com/lovell/sharp/pull/1932)
+  [@MayhemYDG](https://github.com/MayhemYDG)
+
+#### v0.23.1 - 26<sup>th</sup> September 2019
+
+* Ensure `sharp.format.vips` is present and correct (filesystem only).
+  [#1813](https://github.com/lovell/sharp/issues/1813)
+
+* Ensure invalid `width` and `height` provided as options to `resize` throw.
+  [#1817](https://github.com/lovell/sharp/issues/1817)
+
+* Allow use of 'heic' and 'heif' identifiers with `toFormat`.
+  [#1834](https://github.com/lovell/sharp/pull/1834)
+  [@jaubourg](https://github.com/jaubourg)
+
+* Add `premultiplied` option to `composite` operation.
+  [#1835](https://github.com/lovell/sharp/pull/1835)
+  [@Andargor](https://github.com/Andargor)
+
+* Allow instance reuse with differing `toBuffer` options.
+  [#1860](https://github.com/lovell/sharp/pull/1860)
+  [@RaboliotTheGrey](https://github.com/RaboliotTheGrey)
+
+* Ensure image is at least 3x3 pixels before attempting trim operation.
+
 #### v0.23.0 - 29<sup>th</sup> July 2019

 * Remove `overlayWith` previously deprecated in v0.22.0.
--- a/docs/index.md
+++ b/docs/index.md
@@ -7,7 +7,8 @@ is to convert large images in common formats to
 smaller, web-friendly JPEG, PNG and WebP images of varying dimensions.

 Resizing an image is typically 4x-5x faster than using the
-quickest ImageMagick and GraphicsMagick settings.
+quickest ImageMagick and GraphicsMagick settings
+due to its use of [libvips](https://github.com/libvips/libvips).

 Colour spaces, embedded ICC profiles and alpha transparency channels are all handled correctly.
 Lanczos resampling ensures quality is not sacrificed for speed.
@@ -16,7 +17,7 @@ As well as image resizing, operations such as
 rotation, extraction, compositing and gamma correction are available.

 Most modern 64-bit OS X, Windows and Linux systems running
-Node versions 8, 10 and 12
+Node versions 8, 10, 12 and 13
 do not require any additional install or runtime dependencies.

 [![Test Coverage](https://coveralls.io/repos/lovell/sharp/badge.png?branch=master)](https://coveralls.io/r/lovell/sharp?branch=master)
@@ -126,6 +127,10 @@ the help and code contributions of the following people:
 * [Michael B. Klein](https://github.com/mbklein)
 * [Jakub Michálek](https://github.com/Goues)
 * [Ilya Ovdin](https://github.com/iovdin)
+* [Andargor](https://github.com/Andargor)
+* [Nicolas Stepien](https://github.com/MayhemYDG)
+* [Paul Neave](https://github.com/neave)
+* [Brendan Kennedy](https://github.com/rustyguts)

 Thank you!

--- a/docs/install.md
+++ b/docs/install.md
@@ -15,7 +15,7 @@ yarn add sharp
 ### Building from source

 Pre-compiled binaries for sharp are provided for use with
-Node versions 8, 10 and 12 on
+Node versions 8, 10, 12 and 13 on
 64-bit Windows, OS X and Linux platforms.

 Sharp will be built from source at install time when:
@@ -74,9 +74,8 @@ libvips is available in the
 [community repository](https://pkgs.alpinelinux.org/packages?name=vips-dev):

 ```sh
-apk add vips-dev fftw-dev build-base --update-cache \
-    --repository https://alpine.global.ssl.fastly.net/alpine/edge/community/ \
-    --repository https://alpine.global.ssl.fastly.net/alpine/edge/main
+apk add --upgrade --no-cache vips-dev build-base \
+  --repository https://alpine.global.ssl.fastly.net/alpine/v3.10/community/
 ```

 The smaller stack size of musl libc means
@@ -247,6 +246,9 @@ SHARP_DIST_BASE_URL="https://hostname/path/" npm install sharp

 to use `https://hostname/path/libvips-x.y.z-platform.tar.gz`.

+To install the prebuilt sharp binaries from a custom URL, please see
+[https://github.com/prebuild/prebuild-install#custom-binaries](https://github.com/prebuild/prebuild-install#custom-binaries)
+
 ### Licences

 This module is licensed under the terms of the
--- a/docs/performance.md
+++ b/docs/performance.md
@@ -4,16 +4,15 @@

 * AWS EC2 eu-west-1 [c5.large](https://aws.amazon.com/ec2/instance-types/c5/) (2x Xeon Platinum 8124M CPU @ 3.00GHz)
 * Ubuntu 18.04 (hvm-ssd/ubuntu-bionic-18.04-amd64-server-20180912 ami-00035f41c82244dab)
-* Node.js v10.11.0
+* Node.js v12.10.0

 ### The contenders

-* [jimp](https://www.npmjs.com/package/jimp) v0.5.3 - Image processing in pure JavaScript. Provides bicubic interpolation.
-* [mapnik](https://www.npmjs.org/package/mapnik) v4.0.1 - Whilst primarily a map renderer, Mapnik contains bitmap image utilities.
-* [imagemagick-native](https://www.npmjs.com/package/imagemagick-native) v1.9.3 - Wrapper around libmagick++, supports Buffers only.
+* [jimp](https://www.npmjs.com/package/jimp) v0.8.4 - Image processing in pure JavaScript. Provides bicubic interpolation.
+* [mapnik](https://www.npmjs.org/package/mapnik) v4.3.1 - Whilst primarily a map renderer, Mapnik contains bitmap image utilities.
 * [imagemagick](https://www.npmjs.com/package/imagemagick) v0.1.3 - Supports filesystem only and "*has been unmaintained for a long time*".
 * [gm](https://www.npmjs.com/package/gm) v1.23.1 - Fully featured wrapper around GraphicsMagick's `gm` command line utility.
-* sharp v0.21.0 / libvips v8.7.0 - Caching within libvips disabled to ensure a fair comparison.
+* sharp v0.23.1 / libvips v8.8.1 - Caching within libvips disabled to ensure a fair comparison.

 ### The task

@@ -25,14 +24,14 @@ then compress to JPEG at a "quality" setting of 80.

 | Module             | Input  | Output | Ops/sec | Speed-up |
 | :----------------- | :----- | :----- | ------: | -------: |
-| jimp               | buffer | buffer |    0.71 |      1.0 |
-| mapnik             | buffer | buffer |    3.32 |      4.7 |
-| gm                 | buffer | buffer |    3.97 |      5.6 |
-| imagemagick-native | buffer | buffer |    4.06 |      5.7 |
-| imagemagick        | file   | file   |    4.24 |      6.0 |
-| sharp              | stream | stream |   25.30 |     35.6 |
-| sharp              | file   | file   |   26.17 |     36.9 |
-| sharp              | buffer | buffer |   26.45 |     37.3 |
+| jimp               | buffer | buffer |    0.66 |      1.0 |
+| mapnik             | buffer | buffer |    3.31 |      5.0 |
+| gm                 | buffer | buffer |    3.79 |      5.7 |
+| gm                 | file   | file   |    3.82 |      5.8 |
+| imagemagick        | file   | file   |    4.17 |      6.3 |
+| sharp              | stream | stream |   25.81 |     39.1 |
+| sharp              | file   | file   |   26.76 |     40.5 |
+| sharp              | buffer | buffer |   28.06 |     42.5 |

 Greater libvips performance can be expected with caching enabled (default)
 and using 8+ core machines, especially those with larger L1/L2 CPU caches.
--- a/install/libvips.js
+++ b/install/libvips.js
@@ -19,6 +19,9 @@ const distBaseUrl = process.env.npm_config_sharp_dist_base_url || process.env.SH

 const fail = function (err) {
  npmLog.error('sharp', err.message);
+  if (err.code === 'EACCES') {
+    npmLog.info('sharp', 'Are you trying to install as a root or sudo user? Try again with the --unsafe-perm flag');
+  }
  npmLog.info('sharp', 'Attempting to build from source via node-gyp but this may fail due to the above error');
  npmLog.info('sharp', 'Please see https://sharp.pixelplumbing.com/page/install for required dependencies');
  process.exit(1);
@@ -79,14 +82,16 @@ try {
      npmLog.info('sharp', `Downloading ${url}`);
      simpleGet({ url: url, agent: agent() }, function (err, response) {
        if (err) {
-          throw err;
+          fail(err);
+        } else if (response.statusCode === 404) {
+          fail(new Error(`Prebuilt libvips binaries are not yet available for ${platformAndArch}`));
+        } else if (response.statusCode !== 200) {
+          fail(new Error(`Status ${response.statusCode} ${response.statusMessage}`));
+        } else {
+          response
+            .on('error', fail)
+            .pipe(tmpFile);
        }
-        if (response.statusCode !== 200) {
-          throw new Error(`Status ${response.statusCode}`);
-        }
-        response
-          .on('error', fail)
-          .pipe(tmpFile);
      });
      tmpFile
        .on('error', fail)
--- a/lib/agent.js
+++ b/lib/agent.js
@@ -20,15 +20,18 @@ function env (key) {

 module.exports = function () {
  try {
-    const proxy = url.parse(proxies.map(env).find(is.string));
+    const proxy = new url.URL(proxies.map(env).find(is.string));
    const tunnel = proxy.protocol === 'https:'
      ? tunnelAgent.httpsOverHttps
      : tunnelAgent.httpsOverHttp;
+    const proxyAuth = proxy.username && proxy.password
+      ? `${proxy.username}:${proxy.password}`
+      : null;
    return tunnel({
      proxy: {
        port: Number(proxy.port),
        host: proxy.hostname,
-        proxyAuth: proxy.auth
+        proxyAuth
      }
    });
  } catch (err) {
--- a/lib/colour.js
+++ b/lib/colour.js
@@ -83,18 +83,22 @@ function toColorspace (colorspace) {
 * Update a colour attribute of the this.options Object.
 * @private
 * @param {String} key
- * @param {String|Object} val
- * @throws {Error} Invalid key
+ * @param {String|Object} value
+ * @throws {Error} Invalid value
 */
-function _setColourOption (key, val) {
-  if (is.object(val) || is.string(val)) {
-    const colour = color(val);
-    this.options[key] = [
-      colour.red(),
-      colour.green(),
-      colour.blue(),
-      Math.round(colour.alpha() * 255)
-    ];
+function _setBackgroundColourOption (key, value) {
+  if (is.defined(value)) {
+    if (is.object(value) || is.string(value)) {
+      const colour = color(value);
+      this.options[key] = [
+        colour.red(),
+        colour.green(),
+        colour.blue(),
+        Math.round(colour.alpha() * 255)
+      ];
+    } else {
+      throw is.invalidParameterError('background', 'object or string', value);
+    }
  }
 }

@@ -111,7 +115,7 @@ module.exports = function (Sharp) {
    toColourspace,
    toColorspace,
    // Private
-    _setColourOption
+    _setBackgroundColourOption
  });
  // Class attributes
  Sharp.colourspace = colourspace;
--- a/lib/composite.js
+++ b/lib/composite.js
@@ -81,6 +81,7 @@ const blend = {
 * @param {Number} [images[].top] - the pixel offset from the top edge.
 * @param {Number} [images[].left] - the pixel offset from the left edge.
 * @param {Boolean} [images[].tile=false] - set to true to repeat the overlay image across the entire image with the given `gravity`.
+ * @param {Boolean} [images[].premultiplied=false] - set to true to avoid premultipling the image below. Equivalent to the `--premultiplied` vips option.
 * @param {Number} [images[].density=72] - number representing the DPI for vector overlay image.
 * @param {Object} [images[].raw] - describes overlay when using raw pixel data.
 * @param {Number} [images[].raw.width]
@@ -105,7 +106,8 @@ function composite (images) {
      tile: false,
      left: -1,
      top: -1,
-      gravity: 0
+      gravity: 0,
+      premultiplied: false
    };
    if (is.defined(image.blend)) {
      if (is.string(blend[image.blend])) {
@@ -147,6 +149,14 @@ function composite (images) {
        throw is.invalidParameterError('gravity', 'valid gravity', image.gravity);
      }
    }
+    if (is.defined(image.premultiplied)) {
+      if (is.bool(image.premultiplied)) {
+        composite.premultiplied = image.premultiplied;
+      } else {
+        throw is.invalidParameterError('premultiplied', 'boolean', image.premultiplied);
+      }
+    }
+
    return composite;
  });
  return this;
--- a/lib/constructor.js
+++ b/lib/constructor.js
@@ -78,7 +78,7 @@ const debuglog = util.debuglog('sharp');
 *
 * @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.
+ *  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.
@@ -213,6 +213,7 @@ const Sharp = function (input, options) {
    tileSize: 256,
    tileOverlap: 0,
    tileSkipBlanks: -1,
+    tileBackground: [255, 255, 255, 255],
    linearA: 1,
    linearB: 0,
    // Function to notify of libvips warnings
--- a/lib/input.js
+++ b/lib/input.js
@@ -65,11 +65,15 @@ function _createInputDescriptor (input, inputOptions, containerOptions) {
    if (is.defined(inputOptions.pages)) {
      if (is.integer(inputOptions.pages) && is.inRange(inputOptions.pages, -1, 100000)) {
        inputDescriptor.pages = inputOptions.pages;
+      } else {
+        throw is.invalidParameterError('pages', 'integer between -1 and 100000', inputOptions.pages);
      }
    }
    if (is.defined(inputOptions.page)) {
      if (is.integer(inputOptions.page) && is.inRange(inputOptions.page, 0, 100000)) {
        inputDescriptor.page = inputOptions.page;
+      } else {
+        throw is.invalidParameterError('page', 'integer between 0 and 100000', inputOptions.page);
      }
    }
    // Create new image
--- a/lib/operation.js
+++ b/lib/operation.js
@@ -179,7 +179,7 @@ function blur (sigma) {
 function flatten (options) {
  this.options.flatten = is.bool(options) ? options : true;
  if (is.object(options)) {
-    this._setColourOption('flattenBackground', options.background);
+    this._setBackgroundColourOption('flattenBackground', options.background);
  }
  return this;
 }
--- a/lib/output.js
+++ b/lib/output.js
@@ -10,6 +10,9 @@ const sharp = require('../build/Release/sharp.node');
 * with JPEG, PNG, WebP, TIFF, DZI, and libvips' V format supported.
 * Note that raw pixel data is only supported for buffer output.
 *
+ * By default all metadata will be removed, which includes EXIF-based orientation.
+ * See {@link withMetadata} for control over this.
+ *
 * A `Promise` is returned when `callback` is not provided.
 *
 * @example
@@ -57,7 +60,11 @@ function toFile (fileOut, callback) {
 /**
 * Write output to a Buffer.
 * JPEG, PNG, WebP, TIFF and RAW output are supported.
- * By default, the format will match the input image, except GIF and SVG input which become PNG output.
+ *
+ * If no explicit format is set, the output format will match the input image, except GIF and SVG input which become PNG output.
+ *
+ * By default all metadata will be removed, which includes EXIF-based orientation.
+ * See {@link withMetadata} for control over this.
 *
 * `callback`, if present, gets three arguments `(err, data, info)` where:
 * - `err` is an error, if any.
@@ -92,6 +99,8 @@ function toFile (fileOut, callback) {
 function toBuffer (options, callback) {
  if (is.object(options)) {
    this._setBooleanOption('resolveWithObject', options.resolveWithObject);
+  } else if (this.options.resolveWithObject) {
+    this.options.resolveWithObject = false;
  }
  return this._pipeline(is.fn(options) ? options : callback);
 }
@@ -487,6 +496,17 @@ function raw () {
  return this._updateFormatOut('raw');
 }

+const formats = new Map([
+  ['heic', 'heif'],
+  ['heif', 'heif'],
+  ['jpeg', 'jpeg'],
+  ['jpg', 'jpeg'],
+  ['png', 'png'],
+  ['raw', 'raw'],
+  ['tiff', 'tiff'],
+  ['webp', 'webp']
+]);
+
 /**
 * Force output to a given format.
 *
@@ -502,14 +522,11 @@ function raw () {
 * @throws {Error} unsupported format or options
 */
 function toFormat (format, options) {
-  if (is.object(format) && is.string(format.id)) {
-    format = format.id;
+  const actualFormat = formats.get(is.object(format) && is.string(format.id) ? format.id : format);
+  if (!actualFormat) {
+    throw is.invalidParameterError('format', `one of: ${[...formats.keys()].join(', ')}`, format);
  }
-  if (format === 'jpg') format = 'jpeg';
-  if (!is.inArray(format, ['jpeg', 'png', 'webp', 'tiff', 'raw'])) {
-    throw is.invalidParameterError('format', 'one of: jpeg, png, webp, tiff, raw', format);
-  }
-  return this[format](options);
+  return this[actualFormat](options);
 }

 /**
@@ -534,6 +551,7 @@ function toFormat (format, options) {
 * @param {Number} [options.size=256] tile size in pixels, a value between 1 and 8192.
 * @param {Number} [options.overlap=0] tile overlap in pixels, a value between 0 and 8192.
 * @param {Number} [options.angle=0] tile angle of rotation, must be a multiple of 90.
+ * @param {String|Object} [options.background={r: 255, g: 255, b: 255, alpha: 1}] - background colour, parsed by the [color](https://www.npmjs.org/package/color) module, defaults to white without transparency.
 * @param {String} [options.depth] how deep to make the pyramid, possible values are `onepixel`, `onetile` or `one`, default based on layout.
 * @param {Number} [options.skipBlanks=-1] threshold to skip tile generation, a value 0 - 255 for 8-bit images or 0 - 65535 for 16-bit images
 * @param {String} [options.container='fs'] tile container, with value `fs` (filesystem) or `zip` (compressed file).
@@ -557,7 +575,7 @@ function tile (options) {
        if (options.overlap > this.options.tileSize) {
          throw is.invalidParameterError('overlap', `<= size (${this.options.tileSize})`, options.overlap);
        }
-        this.options.tileOverlap = tile.overlap;
+        this.options.tileOverlap = options.overlap;
      } else {
        throw is.invalidParameterError('overlap', 'integer between 0 and 8192', options.overlap);
      }
@@ -586,6 +604,8 @@ function tile (options) {
        throw is.invalidParameterError('angle', 'positive/negative multiple of 90', options.angle);
      }
    }
+    // Background colour
+    this._setBackgroundColourOption('tileBackground', options.background);
    // Depth of tiles
    if (is.defined(options.depth)) {
      if (is.string(options.depth) && is.inArray(options.depth, ['onepixel', 'onetile', 'one'])) {
--- a/lib/platform.js
+++ b/lib/platform.js
@@ -7,6 +7,7 @@ const env = process.env;
 module.exports = function () {
  const arch = env.npm_config_arch || process.arch;
  const platform = env.npm_config_platform || process.platform;
+  /* istanbul ignore next */
  const libc = (platform === 'linux' && detectLibc.isNonGlibcLinux) ? detectLibc.family : '';

  const platformId = [`${platform}${libc}`];
--- a/lib/resize.js
+++ b/lib/resize.js
@@ -210,12 +210,20 @@ function resize (width, height, options) {
  }
  if (is.object(options)) {
    // Width
-    if (is.integer(options.width) && options.width > 0) {
-      this.options.width = options.width;
+    if (is.defined(options.width)) {
+      if (is.integer(options.width) && options.width > 0) {
+        this.options.width = options.width;
+      } else {
+        throw is.invalidParameterError('width', 'positive integer', options.width);
+      }
    }
    // Height
-    if (is.integer(options.height) && options.height > 0) {
-      this.options.height = options.height;
+    if (is.defined(options.height)) {
+      if (is.integer(options.height) && options.height > 0) {
+        this.options.height = options.height;
+      } else {
+        throw is.invalidParameterError('height', 'positive integer', options.height);
+      }
    }
    // Fit
    if (is.defined(options.fit)) {
@@ -238,9 +246,7 @@ function resize (width, height, options) {
      }
    }
    // Background
-    if (is.defined(options.background)) {
-      this._setColourOption('resizeBackground', options.background);
-    }
+    this._setBackgroundColourOption('resizeBackground', options.background);
    // Kernel
    if (is.defined(options.kernel)) {
      if (is.string(kernel[options.kernel])) {
@@ -305,7 +311,7 @@ function extend (extend) {
    this.options.extendBottom = extend.bottom;
    this.options.extendLeft = extend.left;
    this.options.extendRight = extend.right;
-    this._setColourOption('extendBackground', extend.background);
+    this._setBackgroundColourOption('extendBackground', extend.background);
  } else {
    throw is.invalidParameterError('extend', 'integer or object', extend);
  }
@@ -361,7 +367,10 @@ function extract (options) {

 /**
 * Trim "boring" pixels from all edges that contain values similar to the top-left pixel.
+ * Images consisting entirely of a single colour will calculate "boring" using the alpha channel, if any.
+ *
 * The `info` response Object will contain `trimOffsetLeft` and `trimOffsetTop` properties.
+ *
 * @param {Number} [threshold=10] the allowed difference from the top-left pixel, a number greater than zero.
 * @returns {Sharp}
 * @throws {Error} Invalid parameters
--- a/package.json
+++ b/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": "0.23.0",
+  "version": "0.23.3",
  "author": "Lovell Fuller <npm@lovell.info>",
  "homepage": "https://github.com/lovell/sharp",
  "contributors": [
@@ -61,12 +61,15 @@
    "Keith Belovay <keith@picthrive.com>",
    "Michael B. Klein <mbklein@gmail.com>",
    "Jordan Prudhomme <jordan@raboland.fr>",
-    "Ilya Ovdin <iovdin@gmail.com>"
+    "Ilya Ovdin <iovdin@gmail.com>",
+    "Andargor <andargor@yahoo.com>",
+    "Paul Neave <paul.neave@gmail.com>",
+    "Brendan Kennedy <brenwken@gmail.com>"
  ],
  "scripts": {
    "install": "(node install/libvips && node install/dll-copy && prebuild-install) || (node-gyp rebuild && node install/dll-copy)",
    "clean": "rm -rf node_modules/ build/ vendor/ .nyc_output/ coverage/ test/fixtures/output.*",
-    "test": "semistandard && cc && npm run test-unit && npm run test-licensing && prebuild-ci",
+    "test": "semistandard && cpplint && npm run test-unit && npm run test-licensing && prebuild-ci",
    "test-unit": "nyc --reporter=lcov --branches=99 mocha --slow=5000 --timeout=60000 ./test/unit/*.js",
    "test-licensing": "license-checker --production --summary --onlyAllow=\"Apache-2.0;BSD;ISC;MIT\"",
    "test-coverage": "./test/coverage/report.sh",
@@ -74,6 +77,14 @@
    "docs": "for m in constructor input resize composite operation colour channel output utility; do documentation build --shallow --format=md --markdown-toc=false lib/$m.js >docs/api-$m.md; done"
  },
  "main": "lib/index.js",
+  "files": [
+    "binding.gyp",
+    "docs/**",
+    "!docs/css/**",
+    "install/**",
+    "lib/**",
+    "src/**"
+  ],
  "repository": {
    "type": "git",
    "url": "git://github.com/lovell/sharp"
@@ -99,27 +110,27 @@
    "detect-libc": "^1.0.3",
    "nan": "^2.14.0",
    "npmlog": "^4.1.2",
-    "prebuild-install": "^5.3.0",
+    "prebuild-install": "^5.3.3",
    "semver": "^6.3.0",
-    "simple-get": "^3.0.3",
-    "tar": "^4.4.10",
+    "simple-get": "^3.1.0",
+    "tar": "^5.0.5",
    "tunnel-agent": "^0.6.0"
  },
  "devDependencies": {
    "async": "^3.1.0",
-    "cc": "^1.0.2",
+    "cc": "^2.0.1",
    "decompress-zip": "^0.3.2",
-    "documentation": "^12.0.3",
-    "exif-reader": "^1.0.2",
+    "documentation": "^12.1.4",
+    "exif-reader": "^1.0.3",
    "icc": "^1.0.0",
    "license-checker": "^25.0.1",
-    "mocha": "^6.2.0",
-    "mock-fs": "^4.10.1",
+    "mocha": "^6.2.2",
+    "mock-fs": "^4.10.3",
    "nyc": "^14.1.1",
-    "prebuild": "^9.0.1",
+    "prebuild": "^9.1.1",
    "prebuild-ci": "^3.1.0",
-    "rimraf": "^2.6.3",
-    "semistandard": "^13.0.1"
+    "rimraf": "^3.0.0",
+    "semistandard": "^14.2.0"
  },
  "license": "Apache-2.0",
  "config": {
@@ -128,6 +139,9 @@
  "engines": {
    "node": ">=8.5.0"
  },
+  "funding": {
+    "url": "https://opencollective.com/libvips"
+  },
  "semistandard": {
    "env": [
      "mocha"
@@ -136,10 +150,7 @@
  "cc": {
    "linelength": "120",
    "filter": [
-      "build/c++11",
-      "build/include",
-      "runtime/indentation_namespace",
-      "runtime/references"
+      "build/include"
    ]
  }
 }
--- a/src/common.cc
+++ b/src/common.cc
@@ -17,7 +17,7 @@
 #include <string.h>
 #include <vector>
 #include <queue>
-#include <mutex>
+#include <mutex>  // NOLINT(build/c++11)

 #include <node.h>
 #include <node_buffer.h>
@@ -147,7 +147,7 @@ namespace sharp {
      case ImageType::OPENSLIDE: id = "openslide"; break;
      case ImageType::PPM: id = "ppm"; break;
      case ImageType::FITS: id = "fits"; break;
-      case ImageType::VIPS: id = "v"; break;
+      case ImageType::VIPS: id = "vips"; break;
      case ImageType::RAW: id = "raw"; break;
      case ImageType::UNKNOWN: id = "unknown"; break;
      case ImageType::MISSING: id = "missing"; break;
--- a/src/common.h
+++ b/src/common.h
@@ -43,7 +43,7 @@ using vips::VImage;

 namespace sharp {

-  struct InputDescriptor {
+  struct InputDescriptor {  // NOLINT(runtime/indentation_namespace)
    std::string name;
    std::string file;
    char *buffer;
@@ -92,7 +92,7 @@ namespace sharp {

  // Create an InputDescriptor instance from a v8::Object describing an input image
  InputDescriptor* CreateInputDescriptor(
-    v8::Local<v8::Object> input, std::vector<v8::Local<v8::Object>> &buffersToPersist);
+    v8::Local<v8::Object> input, std::vector<v8::Local<v8::Object>> &buffersToPersist);  // NOLINT(runtime/references)

  enum class ImageType {
    JPEG,
--- a/src/operations.cc
+++ b/src/operations.cc
@@ -191,12 +191,20 @@ namespace sharp {
      VImage alpha = image[image.bands() - 1];
      return RemoveAlpha(image)
        .colourspace(VIPS_INTERPRETATION_LCH)
-        .linear({brightness, saturation, 1}, {0, 0, static_cast<double>(hue)})
+        .linear(
+          { brightness, saturation, 1},
+          { 0.0, 0.0, static_cast<double>(hue) }
+        )
+        .colourspace(VIPS_INTERPRETATION_sRGB)
        .bandjoin(alpha);
    } else {
      return image
        .colourspace(VIPS_INTERPRETATION_LCH)
-        .linear({brightness, saturation, 1}, {0, 0, static_cast<double>(hue)});
+        .linear(
+          { brightness, saturation, 1 },
+          { 0.0, 0.0, static_cast<double>(hue) }
+        )
+        .colourspace(VIPS_INTERPRETATION_sRGB);
    }
  }

@@ -250,17 +258,30 @@ namespace sharp {
    Trim an image
  */
  VImage Trim(VImage image, double const threshold) {
+    if (image.width() < 3 && image.height() < 3) {
+      throw VError("Image to trim must be at least 3x3 pixels");
+    }
    // Top-left pixel provides the background colour
    VImage background = image.extract_area(0, 0, 1, 1);
    if (HasAlpha(background)) {
      background = background.flatten();
    }
-    int top, width, height;
-    int const left = image.find_trim(&top, &width, &height, VImage::option()
+    int left, top, width, height;
+    left = image.find_trim(&top, &width, &height, VImage::option()
      ->set("background", background(0, 0))
      ->set("threshold", threshold));
    if (width == 0 || height == 0) {
-      throw VError("Unexpected error while trimming. Try to lower the tolerance");
+      if (HasAlpha(image)) {
+        // Search alpha channel
+        VImage alpha = image[image.bands() - 1];
+        VImage backgroundAlpha = alpha.extract_area(0, 0, 1, 1);
+        left = alpha.find_trim(&top, &width, &height, VImage::option()
+          ->set("background", backgroundAlpha(0, 0))
+          ->set("threshold", threshold));
+      }
+      if (width == 0 || height == 0) {
+        throw VError("Unexpected error while trimming. Try to lower the tolerance");
+      }
    }
    return image.extract_area(left, top, width, height);
  }
--- a/src/pipeline.cc
+++ b/src/pipeline.cc
@@ -38,6 +38,9 @@
 #elif defined(__APPLE__)
 #define STAT64_STRUCT stat
 #define STAT64_FUNCTION stat
+#elif defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || defined(__DragonFly__)
+#define STAT64_STRUCT stat
+#define STAT64_FUNCTION stat
 #else
 #define STAT64_STRUCT stat64
 #define STAT64_FUNCTION stat64
@@ -591,7 +594,7 @@ class PipelineWorker : public Nan::AsyncWorker {
          if (!HasAlpha(compositeImage)) {
            compositeImage = sharp::EnsureAlpha(compositeImage);
          }
-          compositeImage = compositeImage.premultiply();
+          if (!composite->premultiplied) compositeImage = compositeImage.premultiply();
          // Calculate position
          int left;
          int top;
@@ -959,6 +962,11 @@ class PipelineWorker : public Nan::AsyncWorker {
            };
            suffix = AssembleSuffixString(extname, options);
          }
+
+          // Remove alpha channel from tile background if image does not contain an alpha channel
+          if (!HasAlpha(image)) {
+            baton->tileBackground.pop_back();
+          }
          // Write DZ to file
          vips::VOption *options = VImage::option()
                                       ->set("strip", !baton->withMetadata)
@@ -968,6 +976,7 @@ class PipelineWorker : public Nan::AsyncWorker {
                                       ->set("layout", baton->tileLayout)
                                       ->set("suffix", const_cast<char*>(suffix.data()))
                                       ->set("angle", CalculateAngleRotation(baton->tileAngle))
+                                       ->set("background", baton->tileBackground)
                                       ->set("skip_blanks", baton->tileSkipBlanks);

          // libvips chooses a default depth based on layout. Instead of replicating that logic here by
@@ -1230,6 +1239,7 @@ NAN_METHOD(pipeline) {
    composite->left = AttrTo<int32_t>(compositeObject, "left");
    composite->top = AttrTo<int32_t>(compositeObject, "top");
    composite->tile = AttrTo<bool>(compositeObject, "tile");
+    composite->premultiplied = AttrTo<bool>(compositeObject, "premultiplied");
    baton->composite.push_back(composite);
  }
  // Resize options
@@ -1373,6 +1383,7 @@ NAN_METHOD(pipeline) {
  baton->tileOverlap = AttrTo<uint32_t>(options, "tileOverlap");
  std::string tileContainer = AttrAsStr(options, "tileContainer");
  baton->tileAngle = AttrTo<int32_t>(options, "tileAngle");
+  baton->tileBackground = AttrAsRgba(options, "tileBackground");
  baton->tileSkipBlanks = AttrTo<int32_t>(options, "tileSkipBlanks");
  if (tileContainer == "zip") {
    baton->tileContainer = VIPS_FOREIGN_DZ_CONTAINER_ZIP;
--- a/src/pipeline.h
+++ b/src/pipeline.h
@@ -41,6 +41,7 @@ struct Composite {
  int left;
  int top;
  bool tile;
+  bool premultiplied;

  Composite():
    input(nullptr),
@@ -48,7 +49,8 @@ struct Composite {
    gravity(0),
    left(-1),
    top(-1),
-    tile(false) {}
+    tile(false),
+    premultiplied(false) {}
 };

 struct PipelineBaton {
@@ -173,6 +175,7 @@ struct PipelineBaton {
  VipsForeignDzLayout tileLayout;
  std::string tileFormat;
  int tileAngle;
+  std::vector<double> tileBackground;
  int tileSkipBlanks;
  VipsForeignDzDepth tileDepth;
  std::unique_ptr<double[]> recombMatrix;
@@ -278,6 +281,7 @@ struct PipelineBaton {
    tileContainer(VIPS_FOREIGN_DZ_CONTAINER_FS),
    tileLayout(VIPS_FOREIGN_DZ_LAYOUT_DZ),
    tileAngle(0),
+    tileBackground{ 255.0, 255.0, 255.0, 255.0 },
    tileSkipBlanks(-1),
    tileDepth(VIPS_FOREIGN_DZ_DEPTH_LAST) {}
 };
--- a/src/utilities.cc
+++ b/src/utilities.cc
@@ -150,8 +150,9 @@ NAN_METHOD(format) {

  // Which load/save operations are available for each compressed format?
  Local<Object> format = New<Object>();
-  for (std::string f : {
-    "jpeg", "png", "webp", "tiff", "magick", "openslide", "dz", "ppm", "fits", "gif", "svg", "heif", "pdf", "v"
+  for (std::string const f : {
+    "jpeg", "png", "webp", "tiff", "magick", "openslide", "dz",
+    "ppm", "fits", "gif", "svg", "heif", "pdf", "vips"
  }) {
    // Input
    Local<Boolean> hasInputFile =
--- a/test/bench/package.json
+++ b/test/bench/package.json
@@ -12,10 +12,9 @@
    "benchmark": "^2.1.4",
    "gm": "^1.23.1",
    "imagemagick": "^0.1.3",
-    "imagemagick-native": "^1.9.3",
-    "jimp": "^0.6.4",
-    "mapnik": "^4.2.1",
-    "semver": "^6.1.2"
+    "jimp": "^0.8.4",
+    "mapnik": "^4.3.1",
+    "semver": "^6.3.0"
  },
  "license": "Apache-2.0",
  "engines": {
--- a/test/bench/perf.js
+++ b/test/bench/perf.js
@@ -12,12 +12,6 @@ const gm = require('gm');
 const imagemagick = require('imagemagick');
 const mapnik = require('mapnik');
 const jimp = require('jimp');
-let imagemagickNative;
-try {
-  imagemagickNative = require('imagemagick-native');
-} catch (err) {
-  console.log('Excluding imagemagick-native');
-}

 const fixtures = require('../fixtures');

@@ -28,7 +22,7 @@ const height = 588;
 sharp.cache(false);

 async.series({
-  'jpeg': function (callback) {
+  jpeg: function (callback) {
    const inputJpgBuffer = fs.readFileSync(fixtures.inputJpg);
    const jpegSuite = new Benchmark.Suite('jpeg');
    // jimp
@@ -126,29 +120,6 @@ async.series({
        });
      }
    });
-    // imagemagick-native
-    if (typeof imagemagickNative !== 'undefined') {
-      jpegSuite.add('imagemagick-native-buffer-buffer', {
-        defer: true,
-        fn: function (deferred) {
-          imagemagickNative.convert({
-            srcData: inputJpgBuffer,
-            quality: 80,
-            width: width,
-            height: height,
-            format: 'JPEG',
-            filter: 'Lanczos'
-          }, function (err, buffer) {
-            if (err) {
-              throw err;
-            } else {
-              assert.notStrictEqual(null, buffer);
-              deferred.resolve();
-            }
-          });
-        }
-      });
-    }
    // gm
    jpegSuite.add('gm-buffer-file', {
      defer: true,
@@ -289,6 +260,9 @@ async.series({
          .then(function (buffer) {
            assert.notStrictEqual(null, buffer);
            deferred.resolve();
+          })
+          .catch(function (err) {
+            throw err;
          });
      }
    }).on('cycle', function (event) {
@@ -698,22 +672,6 @@ async.series({
        });
      }
    });
-    // imagemagick-native
-    if (typeof imagemagickNative !== 'undefined') {
-      pngSuite.add('imagemagick-native-buffer-buffer', {
-        defer: true,
-        fn: function (deferred) {
-          imagemagickNative.convert({
-            srcData: inputPngBuffer,
-            width: width,
-            height: height,
-            format: 'PNG',
-            filter: 'Lanczos'
-          });
-          deferred.resolve();
-        }
-      });
-    }
    // gm
    pngSuite.add('gm-file-file', {
      defer: true,
--- a/test/fixtures/expected/expected.absent.composite.premultiplied.png
+++ b/test/fixtures/expected/expected.absent.composite.premultiplied.png
--- a/test/fixtures/expected/expected.false.composite.premultiplied.png
+++ b/test/fixtures/expected/expected.false.composite.premultiplied.png
--- a/test/fixtures/expected/expected.true.composite.premultiplied.png
+++ b/test/fixtures/expected/expected.true.composite.premultiplied.png
--- a/test/fixtures/expected/flatten-rgb16-orange.jpg
+++ b/test/fixtures/expected/flatten-rgb16-orange.jpg
--- a/test/fixtures/expected/modulate-linear.jpg
+++ b/test/fixtures/expected/modulate-linear.jpg
--- a/test/fixtures/image-in-alpha.png
+++ b/test/fixtures/image-in-alpha.png
--- a/test/fixtures/index.js
+++ b/test/fixtures/index.js
@@ -13,6 +13,7 @@ const getPath = function (filename) {
 // Based on the dHash gradient method - see http://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html
 const fingerprint = function (image, callback) {
  sharp(image)
+    .flatten('gray')
    .greyscale()
    .normalise()
    .resize(9, 8, { fit: sharp.fit.fill })
@@ -87,6 +88,7 @@ module.exports = {
  inputPngTruncated: getPath('truncated.png'), // gm convert 2569067123_aca715a2ee_o.jpg -resize 320x240 saw.png ; head -c 10000 saw.png > truncated.png
  inputPngEmbed: getPath('embedgravitybird.png'), // Released to sharp under a CC BY 4.0
  inputPngRGBWithAlpha: getPath('2569067123_aca715a2ee_o.png'), // http://www.flickr.com/photos/grizdave/2569067123/ (same as inputJpg)
+  inputPngImageInAlpha: getPath('image-in-alpha.png'), // https://github.com/lovell/sharp/issues/1597

  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
--- a/test/fixtures/input.above.composite.premultiplied.png
+++ b/test/fixtures/input.above.composite.premultiplied.png
--- a/test/fixtures/input.below.composite.premultiplied.png
+++ b/test/fixtures/input.below.composite.premultiplied.png
--- a/test/unit/alpha.js
+++ b/test/unit/alpha.js
@@ -54,7 +54,7 @@ describe('Alpha transparency', function () {
        assert.strictEqual(true, info.size > 0);
        assert.strictEqual(32, info.width);
        assert.strictEqual(32, info.height);
-        fixtures.assertMaxColourDistance(output, fixtures.expected('flatten-rgb16-orange.jpg'), 25);
+        fixtures.assertMaxColourDistance(output, fixtures.expected('flatten-rgb16-orange.jpg'), 10);
        done();
      });
  });
@@ -81,6 +81,18 @@ describe('Alpha transparency', function () {
      });
  });

+  it('Flatten with options but without colour does not throw', () => {
+    assert.doesNotThrow(() => {
+      sharp().flatten({});
+    });
+  });
+
+  it('Flatten to invalid colour throws', () => {
+    assert.throws(() => {
+      sharp().flatten({ background: 1 });
+    });
+  });
+
  it('Enlargement with non-nearest neighbor interpolation shouldn’t cause dark edges', function () {
    const base = 'alpha-premultiply-enlargement-2048x1536-paper.png';
    const actual = fixtures.path('output.' + base);
--- a/test/unit/composite.js
+++ b/test/unit/composite.js
@@ -62,6 +62,65 @@ describe('composite', () => {
    })
  ));

+  it('premultiplied true', () => {
+    const filename = 'composite.premultiplied.png';
+    const below = fixtures.path(`input.below.${filename}`);
+    const above = fixtures.path(`input.above.${filename}`);
+    const actual = fixtures.path(`output.true.${filename}`);
+    const expected = fixtures.expected(`expected.true.${filename}`);
+    return sharp(below)
+      .composite([{
+        input: above,
+        blend: 'color-burn',
+        top: 0,
+        left: 0,
+        premultiplied: true
+      }])
+      .toFile(actual)
+      .then(() => {
+        fixtures.assertMaxColourDistance(actual, expected);
+      });
+  });
+
+  it('premultiplied false', () => {
+    const filename = 'composite.premultiplied.png';
+    const below = fixtures.path(`input.below.${filename}`);
+    const above = fixtures.path(`input.above.${filename}`);
+    const actual = fixtures.path(`output.false.${filename}`);
+    const expected = fixtures.expected(`expected.false.${filename}`);
+    return sharp(below)
+      .composite([{
+        input: above,
+        blend: 'color-burn',
+        top: 0,
+        left: 0,
+        premultiplied: false
+      }])
+      .toFile(actual)
+      .then(() => {
+        fixtures.assertMaxColourDistance(actual, expected);
+      });
+  });
+
+  it('premultiplied absent', () => {
+    const filename = 'composite.premultiplied.png';
+    const below = fixtures.path(`input.below.${filename}`);
+    const above = fixtures.path(`input.above.${filename}`);
+    const actual = fixtures.path(`output.absent.${filename}`);
+    const expected = fixtures.expected(`expected.absent.${filename}`);
+    return sharp(below)
+      .composite([{
+        input: above,
+        blend: 'color-burn',
+        top: 0,
+        left: 0
+      }])
+      .toFile(actual)
+      .then(() => {
+        fixtures.assertMaxColourDistance(actual, expected);
+      });
+  });
+
  it('multiple', () => {
    const filename = 'composite-multiple.png';
    const actual = fixtures.path(`output.${filename}`);
@@ -265,6 +324,12 @@ describe('composite', () => {
      }, /Expected boolean for tile but received invalid of type string/);
    });

+    it('invalid premultiplied', () => {
+      assert.throws(() => {
+        sharp().composite([{ input: 'test', premultiplied: 'invalid' }]);
+      }, /Expected boolean for premultiplied but received invalid of type string/);
+    });
+
    it('invalid left', () => {
      assert.throws(() => {
        sharp().composite([{ input: 'test', left: 0.5 }]);
--- a/test/unit/io.js
+++ b/test/unit/io.js
@@ -648,6 +648,16 @@ describe('Input/output', function () {
    it('Ignore unknown attribute', function () {
      sharp(null, { unknown: true });
    });
+    it('Invalid page property throws', function () {
+      assert.throws(function () {
+        sharp(null, { page: -1 });
+      }, /Expected integer between 0 and 100000 for page but received -1 of type number/);
+    });
+    it('Invalid pages property throws', function () {
+      assert.throws(function () {
+        sharp(null, { pages: '1' });
+      }, /Expected integer between -1 and 100000 for pages but received 1 of type string/);
+    });
  });

  describe('create new image', function () {
--- a/test/unit/jpeg.js
+++ b/test/unit/jpeg.js
@@ -259,4 +259,35 @@ describe('JPEG', function () {
          });
      });
  });
+
+  it('Specifying quantization table provides different JPEG', function (done) {
+    // First generate with default quantization table
+    sharp(fixtures.inputJpg)
+      .resize(320, 240)
+      .jpeg({ optimiseCoding: false })
+      .toBuffer(function (err, withDefaultQuantizationTable, withInfo) {
+        if (err) throw err;
+        assert.strictEqual(true, withDefaultQuantizationTable.length > 0);
+        assert.strictEqual(withDefaultQuantizationTable.length, withInfo.size);
+        assert.strictEqual('jpeg', withInfo.format);
+        assert.strictEqual(320, withInfo.width);
+        assert.strictEqual(240, withInfo.height);
+        // Then generate with different quantization table
+        sharp(fixtures.inputJpg)
+          .resize(320, 240)
+          .jpeg({ optimiseCoding: false, quantizationTable: 3 })
+          .toBuffer(function (err, withQuantTable3, withoutInfo) {
+            if (err) throw err;
+            assert.strictEqual(true, withQuantTable3.length > 0);
+            assert.strictEqual(withQuantTable3.length, withoutInfo.size);
+            assert.strictEqual('jpeg', withoutInfo.format);
+            assert.strictEqual(320, withoutInfo.width);
+            assert.strictEqual(240, withoutInfo.height);
+
+            // Verify image is same (as mozjpeg may not be present) size or less
+            assert.strictEqual(true, withQuantTable3.length <= withDefaultQuantizationTable.length);
+            done();
+          });
+      });
+  });
 });
--- a/test/unit/linear.js
+++ b/test/unit/linear.js
@@ -73,7 +73,7 @@ describe('Linear adjustment', function () {

    assert.throws(function () {
      sharp(fixtures.inputPngOverlayLayer1)
-        .linear(undefined, { 'bar': 'baz' });
+        .linear(undefined, { bar: 'baz' });
    });
  });
 });
--- a/test/unit/metadata.js
+++ b/test/unit/metadata.js
@@ -232,6 +232,26 @@ describe('Image metadata', function () {
      done();
    });
  });
+  it('vips', () =>
+    sharp(fixtures.inputV)
+      .metadata()
+      .then(metadata => {
+        assert.strictEqual('vips', metadata.format);
+        assert.strictEqual('undefined', typeof metadata.size);
+        assert.strictEqual(70, metadata.width);
+        assert.strictEqual(60, metadata.height);
+        assert.strictEqual(3, metadata.channels);
+        assert.strictEqual('uchar', metadata.depth);
+        assert.strictEqual(72, metadata.density);
+        assert.strictEqual('undefined', typeof metadata.chromaSubsampling);
+        assert.strictEqual(false, metadata.isProgressive);
+        assert.strictEqual(false, metadata.hasProfile);
+        assert.strictEqual(false, metadata.hasAlpha);
+        assert.strictEqual('undefined', typeof metadata.orientation);
+        assert.strictEqual('undefined', typeof metadata.exif);
+        assert.strictEqual('undefined', typeof metadata.icc);
+      })
+  );

  it('File in, Promise out', function (done) {
    sharp(fixtures.inputJpg).metadata().then(function (metadata) {
@@ -287,6 +307,20 @@ describe('Image metadata', function () {
    readable.pipe(pipeline);
  });

+  it('Stream in, rejected Promise out', () => {
+    const pipeline = sharp();
+    fs
+      .createReadStream(__filename)
+      .pipe(pipeline);
+
+    return pipeline
+      .metadata()
+      .then(
+        () => Promise.reject(new Error('Expected metadata to reject')),
+        err => assert.strictEqual(err.message, 'Input buffer contains unsupported image format')
+      );
+  });
+
  it('Stream', function (done) {
    const readable = fs.createReadStream(fixtures.inputJpg);
    const pipeline = sharp().metadata(function (err, metadata) {
@@ -370,6 +404,34 @@ describe('Image metadata', function () {
      });
  });

+  it('Include metadata in output, enabled via empty object', () =>
+    sharp(fixtures.inputJpgWithExif)
+      .withMetadata({})
+      .toBuffer()
+      .then((buffer) => sharp(buffer)
+        .metadata()
+        .then(metadata => {
+          assert.strictEqual(true, metadata.hasProfile);
+          assert.strictEqual(8, metadata.orientation);
+          assert.strictEqual('object', typeof metadata.exif);
+          assert.strictEqual(true, metadata.exif instanceof Buffer);
+          // EXIF
+          const exif = exifReader(metadata.exif);
+          assert.strictEqual('object', typeof exif);
+          assert.strictEqual('object', typeof exif.image);
+          assert.strictEqual('number', typeof exif.image.XResolution);
+          // ICC
+          assert.strictEqual('object', typeof metadata.icc);
+          assert.strictEqual(true, metadata.icc instanceof Buffer);
+          const profile = icc.parse(metadata.icc);
+          assert.strictEqual('object', typeof profile);
+          assert.strictEqual('RGB', profile.colorSpace);
+          assert.strictEqual('Perceptual', profile.intent);
+          assert.strictEqual('Monitor', profile.deviceClass);
+        })
+      )
+  );
+
  it('Remove EXIF metadata after a resize', function (done) {
    sharp(fixtures.inputJpgWithExif)
      .resize(320, 240)
--- a/test/unit/modulate.js
+++ b/test/unit/modulate.js
@@ -122,4 +122,21 @@ describe('Modulate', function () {
      });
    });
  });
+
+  it('should be able to use linear and modulate together', function () {
+    const base = 'modulate-linear.jpg';
+    const actual = fixtures.path('output.' + base);
+    const expected = fixtures.expected(base);
+
+    const contrast = 1.5;
+    const brightness = 0.5;
+
+    return sharp(fixtures.testPattern)
+      .linear(contrast, -(128 * contrast) + 128)
+      .modulate({ brightness })
+      .toFile(actual)
+      .then(function () {
+        fixtures.assertMaxColourDistance(actual, expected);
+      });
+  });
 });
--- a/test/unit/raw.js
+++ b/test/unit/raw.js
@@ -53,7 +53,8 @@ describe('Raw pixel data', function () {
              width: info.width,
              height: info.height,
              channels: info.channels
-            } })
+            }
+          })
            .jpeg()
            .toBuffer(function (err, data, info) {
              if (err) throw err;
@@ -81,7 +82,8 @@ describe('Raw pixel data', function () {
              width: info.width,
              height: info.height,
              channels: info.channels
-            } })
+            }
+          })
            .png()
            .toBuffer(function (err, data, info) {
              if (err) throw err;
--- a/test/unit/resize.js
+++ b/test/unit/resize.js
@@ -87,6 +87,18 @@ describe('Resize dimensions', function () {
    }, /Expected positive integer for height but received 1.5 of type number/);
  });

+  it('Invalid width - via options', () => {
+    assert.throws(() => {
+      sharp().resize({ width: 1.5, height: 240 });
+    }, /Expected positive integer for width but received 1.5 of type number/);
+  });
+
+  it('Invalid height - via options', () => {
+    assert.throws(() => {
+      sharp().resize({ width: 320, height: 1.5 });
+    }, /Expected positive integer for height but received 1.5 of type number/);
+  });
+
  it('Invalid width - too large', function (done) {
    sharp(fixtures.inputJpg)
      .resize(0x4000, 1)
--- a/test/unit/stats.js
+++ b/test/unit/stats.js
@@ -27,52 +27,52 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.319914765248541));

      // red channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(255, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 615101275));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 83061892917));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 101.44954540768993));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 58.373870588815414));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(255, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 615101275));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 83061892917));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 101.44954540768993));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 58.373870588815414));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2725));

      // green channel
-      assert.strictEqual(0, stats.channels[1]['min']);
-      assert.strictEqual(255, stats.channels[1]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['sum'], 462824115));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['squaresSum'], 47083677255));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['mean'], 76.33425255128337));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['stdev'], 44.03023262954866));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[1].min);
+      assert.strictEqual(255, stats.channels[1].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].sum, 462824115));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].squaresSum, 47083677255));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].mean, 76.33425255128337));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].stdev, 44.03023262954866));
+      assert.strictEqual(true, isInteger(stats.channels[1].minX));
+      assert.strictEqual(true, isInRange(stats.channels[1].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[1].minY));
+      assert.strictEqual(true, isInRange(stats.channels[1].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxY, 0, 2725));

      // blue channel
-      assert.strictEqual(0, stats.channels[2]['min']);
-      assert.strictEqual(255, stats.channels[2]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['sum'], 372986756));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['squaresSum'], 32151543524));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['mean'], 61.51724663436759));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['stdev'], 38.96702865090125));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[2].min);
+      assert.strictEqual(255, stats.channels[2].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].sum, 372986756));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].squaresSum, 32151543524));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].mean, 61.51724663436759));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].stdev, 38.96702865090125));
+      assert.strictEqual(true, isInteger(stats.channels[2].minX));
+      assert.strictEqual(true, isInRange(stats.channels[2].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[2].minY));
+      assert.strictEqual(true, isInRange(stats.channels[2].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxY, 0, 2725));

      done();
    });
@@ -86,20 +86,20 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 0.3409031108021736));

      // red channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(255, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 1391368230));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 354798898650));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 238.8259925648822));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 62.15121915523771));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2809));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2074));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2809));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2074));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(255, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 1391368230));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 354798898650));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 238.8259925648822));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 62.15121915523771));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2809));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2074));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2809));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2074));
      done();
    });
  });
@@ -112,68 +112,68 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 0.06778064835816622));

      // red channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(255, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 795678795));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 202898092725));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 252.9394769668579));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 22.829537532816));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2048));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 1536));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2048));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 1536));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(255, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 795678795));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 202898092725));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 252.9394769668579));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 22.829537532816));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2048));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 1536));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2048));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 1536));

      // green channel
-      assert.strictEqual(0, stats.channels[1]['min']);
-      assert.strictEqual(255, stats.channels[1]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['sum'], 795678795));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['squaresSum'], 202898092725));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['mean'], 252.9394769668579));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['stdev'], 22.829537532816));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minX'], 0, 2048));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minY'], 0, 1536));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxX'], 0, 2048));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxY'], 0, 1536));
+      assert.strictEqual(0, stats.channels[1].min);
+      assert.strictEqual(255, stats.channels[1].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].sum, 795678795));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].squaresSum, 202898092725));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].mean, 252.9394769668579));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].stdev, 22.829537532816));
+      assert.strictEqual(true, isInteger(stats.channels[1].minX));
+      assert.strictEqual(true, isInRange(stats.channels[1].minX, 0, 2048));
+      assert.strictEqual(true, isInteger(stats.channels[1].minY));
+      assert.strictEqual(true, isInRange(stats.channels[1].minY, 0, 1536));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxX, 0, 2048));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxY, 0, 1536));

      // blue channel
-      assert.strictEqual(0, stats.channels[2]['min']);
-      assert.strictEqual(255, stats.channels[2]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['sum'], 795678795));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['squaresSum'], 202898092725));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['mean'], 252.9394769668579));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['stdev'], 22.829537532816));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minX'], 0, 2048));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minY'], 0, 1536));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxX'], 0, 2048));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxY'], 0, 1536));
+      assert.strictEqual(0, stats.channels[2].min);
+      assert.strictEqual(255, stats.channels[2].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].sum, 795678795));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].squaresSum, 202898092725));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].mean, 252.9394769668579));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].stdev, 22.829537532816));
+      assert.strictEqual(true, isInteger(stats.channels[2].minX));
+      assert.strictEqual(true, isInRange(stats.channels[2].minX, 0, 2048));
+      assert.strictEqual(true, isInteger(stats.channels[2].minY));
+      assert.strictEqual(true, isInRange(stats.channels[2].minY, 0, 1536));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxX, 0, 2048));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxY, 0, 1536));

      // alpha channel
-      assert.strictEqual(0, stats.channels[3]['min']);
-      assert.strictEqual(255, stats.channels[3]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[3]['sum'], 5549142));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[3]['squaresSum'], 1333571132));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[3]['mean'], 1.7640247344970703));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[3]['stdev'], 20.51387814157297));
-      assert.strictEqual(true, isInteger(stats.channels[3]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[3]['minX'], 0, 2048));
-      assert.strictEqual(true, isInteger(stats.channels[3]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[3]['minY'], 0, 1536));
-      assert.strictEqual(true, isInteger(stats.channels[3]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[3]['maxX'], 0, 2048));
-      assert.strictEqual(true, isInteger(stats.channels[3]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[3]['maxY'], 0, 1536));
+      assert.strictEqual(0, stats.channels[3].min);
+      assert.strictEqual(255, stats.channels[3].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[3].sum, 5549142));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[3].squaresSum, 1333571132));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[3].mean, 1.7640247344970703));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[3].stdev, 20.51387814157297));
+      assert.strictEqual(true, isInteger(stats.channels[3].minX));
+      assert.strictEqual(true, isInRange(stats.channels[3].minX, 0, 2048));
+      assert.strictEqual(true, isInteger(stats.channels[3].minY));
+      assert.strictEqual(true, isInRange(stats.channels[3].minY, 0, 1536));
+      assert.strictEqual(true, isInteger(stats.channels[3].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[3].maxX, 0, 2048));
+      assert.strictEqual(true, isInteger(stats.channels[3].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[3].maxY, 0, 1536));

      done();
    });
@@ -187,20 +187,20 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 0));

      // alpha channel
-      assert.strictEqual(0, stats.channels[3]['min']);
-      assert.strictEqual(0, stats.channels[3]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[3]['sum'], 0));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[3]['squaresSum'], 0));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[3]['mean'], 0));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[3]['stdev'], 0));
-      assert.strictEqual(true, isInteger(stats.channels[3]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[3]['minX'], 0, 300));
-      assert.strictEqual(true, isInteger(stats.channels[3]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[3]['minY'], 0, 300));
-      assert.strictEqual(true, isInteger(stats.channels[3]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[3]['maxX'], 0, 300));
-      assert.strictEqual(true, isInteger(stats.channels[3]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[3]['maxY'], 0, 300));
+      assert.strictEqual(0, stats.channels[3].min);
+      assert.strictEqual(0, stats.channels[3].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[3].sum, 0));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[3].squaresSum, 0));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[3].mean, 0));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[3].stdev, 0));
+      assert.strictEqual(true, isInteger(stats.channels[3].minX));
+      assert.strictEqual(true, isInRange(stats.channels[3].minX, 0, 300));
+      assert.strictEqual(true, isInteger(stats.channels[3].minY));
+      assert.strictEqual(true, isInRange(stats.channels[3].minY, 0, 300));
+      assert.strictEqual(true, isInteger(stats.channels[3].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[3].maxX, 0, 300));
+      assert.strictEqual(true, isInteger(stats.channels[3].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[3].maxY, 0, 300));

      done();
    });
@@ -214,20 +214,20 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 0.3851250782608986));

      // red channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(255, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 1887266220));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 481252886100));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 235.81772349417824));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 67.25712856093298));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2464));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 3248));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2464));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 3248));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(255, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 1887266220));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 481252886100));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 235.81772349417824));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 67.25712856093298));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2464));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 3248));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2464));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 3248));

      done();
    });
@@ -241,52 +241,52 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.51758075132966));

      // red channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(255, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 83291370));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 11379783198));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 105.36169496842616));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 57.39412151419967));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 1024));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 772));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 1024));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 772));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(255, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 83291370));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 11379783198));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 105.36169496842616));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 57.39412151419967));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 1024));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 772));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 1024));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 772));

      // green channel
-      assert.strictEqual(0, stats.channels[1]['min']);
-      assert.strictEqual(255, stats.channels[1]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['sum'], 120877425));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['squaresSum'], 20774687595));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['mean'], 152.9072025279307));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['stdev'], 53.84143349689916));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minX'], 0, 1024));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minY'], 0, 772));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxX'], 0, 1024));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxY'], 0, 772));
+      assert.strictEqual(0, stats.channels[1].min);
+      assert.strictEqual(255, stats.channels[1].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].sum, 120877425));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].squaresSum, 20774687595));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].mean, 152.9072025279307));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].stdev, 53.84143349689916));
+      assert.strictEqual(true, isInteger(stats.channels[1].minX));
+      assert.strictEqual(true, isInRange(stats.channels[1].minX, 0, 1024));
+      assert.strictEqual(true, isInteger(stats.channels[1].minY));
+      assert.strictEqual(true, isInRange(stats.channels[1].minY, 0, 772));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxX, 0, 1024));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxY, 0, 772));

      // blue channel
-      assert.strictEqual(0, stats.channels[2]['min']);
-      assert.strictEqual(255, stats.channels[2]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['sum'], 138938859));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['squaresSum'], 28449125593));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['mean'], 175.75450711423252));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['stdev'], 71.39929031070358));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minX'], 0, 1024));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minY'], 0, 772));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxX'], 0, 1024));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxY'], 0, 772));
+      assert.strictEqual(0, stats.channels[2].min);
+      assert.strictEqual(255, stats.channels[2].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].sum, 138938859));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].squaresSum, 28449125593));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].mean, 175.75450711423252));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].stdev, 71.39929031070358));
+      assert.strictEqual(true, isInteger(stats.channels[2].minX));
+      assert.strictEqual(true, isInRange(stats.channels[2].minX, 0, 1024));
+      assert.strictEqual(true, isInteger(stats.channels[2].minY));
+      assert.strictEqual(true, isInRange(stats.channels[2].minY, 0, 772));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxX, 0, 1024));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxY, 0, 772));

      done();
    });
@@ -300,52 +300,52 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 6.087309412541799));

      // red channel
-      assert.strictEqual(35, stats.channels[0]['min']);
-      assert.strictEqual(254, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 56088385));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 8002132113));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 131.53936444652908));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 38.26389131415863));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 800));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 533));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 800));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 533));
+      assert.strictEqual(35, stats.channels[0].min);
+      assert.strictEqual(254, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 56088385));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 8002132113));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 131.53936444652908));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 38.26389131415863));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 800));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 533));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 800));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 533));

      // green channel
-      assert.strictEqual(43, stats.channels[1]['min']);
-      assert.strictEqual(255, stats.channels[1]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['sum'], 58612156));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['squaresSum'], 8548344254));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['mean'], 137.45815196998123));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['stdev'], 33.955424103758205));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minX'], 0, 800));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minY'], 0, 533));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxX'], 0, 800));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxY'], 0, 533));
+      assert.strictEqual(43, stats.channels[1].min);
+      assert.strictEqual(255, stats.channels[1].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].sum, 58612156));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].squaresSum, 8548344254));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].mean, 137.45815196998123));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].stdev, 33.955424103758205));
+      assert.strictEqual(true, isInteger(stats.channels[1].minX));
+      assert.strictEqual(true, isInRange(stats.channels[1].minX, 0, 800));
+      assert.strictEqual(true, isInteger(stats.channels[1].minY));
+      assert.strictEqual(true, isInRange(stats.channels[1].minY, 0, 533));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxX, 0, 800));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxY, 0, 533));

      // blue channel
-      assert.strictEqual(51, stats.channels[2]['min']);
-      assert.strictEqual(254, stats.channels[2]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['sum'], 49628525));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['squaresSum'], 6450556071));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['mean'], 116.38959896810506));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['stdev'], 39.7669551046809));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minX'], 0, 800));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minY'], 0, 533));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxX'], 0, 800));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxY'], 0, 533));
+      assert.strictEqual(51, stats.channels[2].min);
+      assert.strictEqual(254, stats.channels[2].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].sum, 49628525));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].squaresSum, 6450556071));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].mean, 116.38959896810506));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].stdev, 39.7669551046809));
+      assert.strictEqual(true, isInteger(stats.channels[2].minX));
+      assert.strictEqual(true, isInRange(stats.channels[2].minX, 0, 800));
+      assert.strictEqual(true, isInteger(stats.channels[2].minY));
+      assert.strictEqual(true, isInRange(stats.channels[2].minY, 0, 533));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxX, 0, 800));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxY, 0, 533));

      done();
    });
@@ -359,36 +359,36 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 1));

      // gray channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(101, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 101));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 10201));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 50.5));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 71.4177848998413));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 1));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 1));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(101, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 101));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 10201));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 50.5));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 71.4177848998413));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 1));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 1));

      // alpha channel
-      assert.strictEqual(0, stats.channels[1]['min']);
-      assert.strictEqual(255, stats.channels[1]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['sum'], 255));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['squaresSum'], 65025));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['mean'], 127.5));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['stdev'], 180.31222920256963));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minX'], 0, 2));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minY'], 0, 1));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxX'], 0, 2));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxY'], 0, 1));
+      assert.strictEqual(0, stats.channels[1].min);
+      assert.strictEqual(255, stats.channels[1].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].sum, 255));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].squaresSum, 65025));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].mean, 127.5));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].stdev, 180.31222920256963));
+      assert.strictEqual(true, isInteger(stats.channels[1].minX));
+      assert.strictEqual(true, isInRange(stats.channels[1].minX, 0, 2));
+      assert.strictEqual(true, isInteger(stats.channels[1].minY));
+      assert.strictEqual(true, isInRange(stats.channels[1].minY, 0, 1));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxX, 0, 2));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxY, 0, 1));

      done();
    });
@@ -412,52 +412,52 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.319914765248541));

      // red channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(255, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 615101275));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 83061892917));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 101.44954540768993));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 58.373870588815414));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(255, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 615101275));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 83061892917));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 101.44954540768993));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 58.373870588815414));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2725));

      // green channel
-      assert.strictEqual(0, stats.channels[1]['min']);
-      assert.strictEqual(255, stats.channels[1]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['sum'], 462824115));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['squaresSum'], 47083677255));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['mean'], 76.33425255128337));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['stdev'], 44.03023262954866));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[1]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[1]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[1]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[1].min);
+      assert.strictEqual(255, stats.channels[1].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].sum, 462824115));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].squaresSum, 47083677255));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].mean, 76.33425255128337));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].stdev, 44.03023262954866));
+      assert.strictEqual(true, isInteger(stats.channels[1].minX));
+      assert.strictEqual(true, isInRange(stats.channels[1].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[1].minY));
+      assert.strictEqual(true, isInRange(stats.channels[1].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[1].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[1].maxY, 0, 2725));

      // blue channel
-      assert.strictEqual(0, stats.channels[2]['min']);
-      assert.strictEqual(255, stats.channels[2]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['sum'], 372986756));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['squaresSum'], 32151543524));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['mean'], 61.51724663436759));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['stdev'], 38.96702865090125));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[2]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[2]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[2]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[2].min);
+      assert.strictEqual(255, stats.channels[2].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].sum, 372986756));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].squaresSum, 32151543524));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].mean, 61.51724663436759));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].stdev, 38.96702865090125));
+      assert.strictEqual(true, isInteger(stats.channels[2].minX));
+      assert.strictEqual(true, isInRange(stats.channels[2].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[2].minY));
+      assert.strictEqual(true, isInRange(stats.channels[2].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[2].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[2].maxY, 0, 2725));

      done();
    });
@@ -474,52 +474,52 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.319914765248541));

      // red channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(255, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 615101275));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 83061892917));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 101.44954540768993));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 58.373870588815414));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(255, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 615101275));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 83061892917));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 101.44954540768993));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 58.373870588815414));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2725));

      // green channel
-      assert.strictEqual(0, stats.channels[1]['min']);
-      assert.strictEqual(255, stats.channels[1]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['sum'], 462824115));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['squaresSum'], 47083677255));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['mean'], 76.33425255128337));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['stdev'], 44.03023262954866));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[1].min);
+      assert.strictEqual(255, stats.channels[1].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].sum, 462824115));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].squaresSum, 47083677255));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].mean, 76.33425255128337));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].stdev, 44.03023262954866));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2725));

      // blue channel
-      assert.strictEqual(0, stats.channels[2]['min']);
-      assert.strictEqual(255, stats.channels[2]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['sum'], 372986756));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['squaresSum'], 32151543524));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['mean'], 61.51724663436759));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['stdev'], 38.96702865090125));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[2].min);
+      assert.strictEqual(255, stats.channels[2].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].sum, 372986756));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].squaresSum, 32151543524));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].mean, 61.51724663436759));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].stdev, 38.96702865090125));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2725));
    }).catch(function (err) {
      throw err;
    });
@@ -531,52 +531,52 @@ describe('Image Stats', function () {
      assert.strictEqual(true, isInAcceptableRange(stats.entropy, 7.319914765248541));

      // red channel
-      assert.strictEqual(0, stats.channels[0]['min']);
-      assert.strictEqual(255, stats.channels[0]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['sum'], 615101275));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['squaresSum'], 83061892917));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['mean'], 101.44954540768993));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[0]['stdev'], 58.373870588815414));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[0].min);
+      assert.strictEqual(255, stats.channels[0].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].sum, 615101275));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].squaresSum, 83061892917));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].mean, 101.44954540768993));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[0].stdev, 58.373870588815414));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2725));

      // green channel
-      assert.strictEqual(0, stats.channels[1]['min']);
-      assert.strictEqual(255, stats.channels[1]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['sum'], 462824115));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['squaresSum'], 47083677255));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['mean'], 76.33425255128337));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[1]['stdev'], 44.03023262954866));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[1].min);
+      assert.strictEqual(255, stats.channels[1].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].sum, 462824115));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].squaresSum, 47083677255));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].mean, 76.33425255128337));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[1].stdev, 44.03023262954866));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2725));

      // blue channel
-      assert.strictEqual(0, stats.channels[2]['min']);
-      assert.strictEqual(255, stats.channels[2]['max']);
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['sum'], 372986756));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['squaresSum'], 32151543524));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['mean'], 61.51724663436759));
-      assert.strictEqual(true, isInAcceptableRange(stats.channels[2]['stdev'], 38.96702865090125));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['minY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['minY'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxX']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxX'], 0, 2725));
-      assert.strictEqual(true, isInteger(stats.channels[0]['maxY']));
-      assert.strictEqual(true, isInRange(stats.channels[0]['maxY'], 0, 2725));
+      assert.strictEqual(0, stats.channels[2].min);
+      assert.strictEqual(255, stats.channels[2].max);
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].sum, 372986756));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].squaresSum, 32151543524));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].mean, 61.51724663436759));
+      assert.strictEqual(true, isInAcceptableRange(stats.channels[2].stdev, 38.96702865090125));
+      assert.strictEqual(true, isInteger(stats.channels[0].minX));
+      assert.strictEqual(true, isInRange(stats.channels[0].minX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].minY));
+      assert.strictEqual(true, isInRange(stats.channels[0].minY, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxX));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxX, 0, 2725));
+      assert.strictEqual(true, isInteger(stats.channels[0].maxY));
+      assert.strictEqual(true, isInRange(stats.channels[0].maxY, 0, 2725));
    }).catch(function (err) {
      throw err;
    });
--- a/test/unit/tiff.js
+++ b/test/unit/tiff.js
@@ -2,6 +2,7 @@

 const fs = require('fs');
 const assert = require('assert');
+const promisify = require('util').promisify;
 const rimraf = require('rimraf');

 const sharp = require('../../');
@@ -85,6 +86,19 @@ describe('TIFF', function () {
      });
  });

+  it('Increasing TIFF quality increases file size', () =>
+    sharp(fixtures.inputJpgWithLandscapeExif1)
+      .tiff({ quality: 40 })
+      .toBuffer()
+      .then(tiff40 => sharp(fixtures.inputJpgWithLandscapeExif1)
+        .tiff({ quality: 90 })
+        .toBuffer()
+        .then(tiff90 =>
+          assert.strictEqual(true, tiff40.length < tiff90.length)
+        )
+      )
+  );
+
  it('Invalid TIFF quality throws error', function () {
    assert.throws(function () {
      sharp().tiff({ quality: 101 });
@@ -137,40 +151,40 @@ describe('TIFF', function () {
    });
  });

-  it('TIFF setting xres and yres on file', function (done) {
-    const res = 1000.0; // inputTiff has a dpi of 300 (res*2.54)
+  it('TIFF setting xres and yres on file', () =>
    sharp(fixtures.inputTiff)
      .tiff({
-        xres: (res),
-        yres: (res)
+        xres: 1000,
+        yres: 1000
      })
-      .toFile(fixtures.outputTiff, (err, info) => {
-        if (err) throw err;
-        assert.strictEqual('tiff', info.format);
-        sharp(fixtures.outputTiff).metadata(function (err, metadata) {
-          if (err) throw err;
-          assert.strictEqual(metadata.density, res * 2.54); // convert to dpi
-          rimraf(fixtures.outputTiff, done);
-        });
-      });
-  });
+      .toFile(fixtures.outputTiff)
+      .then(() => sharp(fixtures.outputTiff)
+        .metadata()
+        .then(({ density }) => {
+          assert.strictEqual(true,
+            density === 2540 || // libvips <= 8.8.2
+            density === 25400); // libvips >= 8.8.3
+          return promisify(rimraf)(fixtures.outputTiff);
+        })
+      )
+  );

-  it('TIFF setting xres and yres on buffer', function (done) {
-    const res = 1000.0; // inputTiff has a dpi of 300 (res*2.54)
+  it('TIFF setting xres and yres on buffer', () =>
    sharp(fixtures.inputTiff)
      .tiff({
-        xres: (res),
-        yres: (res)
+        xres: 1000,
+        yres: 1000
      })
-      .toBuffer(function (err, data, info) {
-        if (err) throw err;
-        sharp(data).metadata(function (err, metadata) {
-          if (err) throw err;
-          assert.strictEqual(metadata.density, res * 2.54); // convert to dpi
-          done();
-        });
-      });
-  });
+      .toBuffer()
+      .then(data => sharp(data)
+        .metadata()
+        .then(({ density }) => {
+          assert.strictEqual(true,
+            density === 2540 || // libvips <= 8.8.2
+            density === 25400); // libvips >= 8.8.3
+        })
+      )
+  );

  it('TIFF invalid xres value should throw an error', function () {
    assert.throws(function () {
--- a/test/unit/tile.js
+++ b/test/unit/tile.js
@@ -56,7 +56,7 @@ const assertZoomifyTiles = function (directory, expectedTileSize, expectedLevels
    fs.readdirSync(path.join(directory, 'TileGroup0')).forEach(function (tile) {
      // Verify tile file name
      assert.ok(/^[0-9]+-[0-9]+-[0-9]+\.jpg$/.test(tile));
-      let level = parseInt(tile.split('-')[0]);
+      const level = parseInt(tile.split('-')[0]);
      maxTileLevel = Math.max(maxTileLevel, level);
    });

@@ -91,6 +91,29 @@ const assertGoogleTiles = function (directory, expectedTileSize, expectedLevels,
  });
 };

+// Verifies tiles at specified level in a given output directory are > size+overlap
+const assertTileOverlap = function (directory, tileSize, done) {
+  // Get sorted levels
+  const levels = fs.readdirSync(directory).sort((a, b) => a - b);
+  // Select the highest tile level
+  const highestLevel = levels[levels.length - 1];
+  // Get sorted tiles from greatest level
+  const tiles = fs.readdirSync(path.join(directory, highestLevel)).sort();
+  // Select a tile from the approximate center of the image
+  const squareTile = path.join(directory, highestLevel, tiles[Math.floor(tiles.length / 2)]);
+
+  sharp(squareTile).metadata(function (err, metadata) {
+    if (err) {
+      throw err;
+    } else {
+      // Tile with an overlap should be larger than original size
+      assert.strictEqual(true, metadata.width > tileSize);
+      assert.strictEqual(true, metadata.height > tileSize);
+      done();
+    }
+  });
+};
+
 describe('Tile', function () {
  it('Valid size values pass', function () {
    [1, 8192].forEach(function (size) {
@@ -297,7 +320,9 @@ describe('Tile', function () {
          assert.strictEqual(2225, info.height);
          assert.strictEqual(3, info.channels);
          assert.strictEqual('undefined', typeof info.size);
-          assertDeepZoomTiles(directory, 512 + (2 * 16), 13, done);
+          assertDeepZoomTiles(directory, 512 + (2 * 16), 13, function () {
+            assertTileOverlap(directory, 512, done);
+          });
        });
    });
  });
@@ -319,7 +344,7 @@ describe('Tile', function () {
          assert.strictEqual('undefined', typeof info.size);
          assertDeepZoomTiles(directory, 512, 13, done);
          // Verifies tiles in 10th level are rotated
-          let tile = path.join(directory, '10', '0_1.jpeg');
+          const tile = path.join(directory, '10', '0_1.jpeg');
          // verify that the width and height correspond to the rotated image
          // expected are w=512 and h=170 for the 0_1.jpeg.
          // if a 0 angle is supplied to the .tile function
@@ -396,7 +421,7 @@ describe('Tile', function () {
          if (err) throw err;
          // assert them 0_0.jpeg doesn't exist because it's a white tile
          const whiteTilePath = path.join(directory, '11', '0_0.jpeg');
-          assert.strictEqual(fs.existsSync(whiteTilePath), false, `Tile shouldn't exist`);
+          assert.strictEqual(fs.existsSync(whiteTilePath), false, 'Tile should not exist');
          // Verify only one depth generated
          assertDeepZoomTiles(directory, 256, 12, done);
        });
@@ -503,7 +528,7 @@ describe('Tile', function () {
          if (err) throw err;
          // assert them 0_0.jpeg doesn't exist because it's a white tile
          const whiteTilePath = path.join(directory, 'TileGroup0', '2-0-0.jpg');
-          assert.strictEqual(fs.existsSync(whiteTilePath), false, `Tile shouldn't exist`);
+          assert.strictEqual(fs.existsSync(whiteTilePath), false, 'Tile should not exist');
          assert.strictEqual('dz', info.format);
          assert.strictEqual(2048, info.width);
          assert.strictEqual(1536, info.height);
@@ -727,7 +752,7 @@ describe('Tile', function () {
          if (err) throw err;

          const whiteTilePath = path.join(directory, '4', '8', '0.jpg');
-          assert.strictEqual(fs.existsSync(whiteTilePath), false, `Tile shouldn't exist`);
+          assert.strictEqual(fs.existsSync(whiteTilePath), false, 'Tile should not exist');

          assert.strictEqual('dz', info.format);
          assert.strictEqual(2809, info.width);
--- a/test/unit/toBuffer.js
+++ b/test/unit/toBuffer.js
@@ -0,0 +1,19 @@
+'use strict';
+
+const assert = require('assert');
+
+const sharp = require('../../');
+const fixtures = require('../fixtures');
+
+describe('toBuffer', () => {
+  it('reusing same sharp object does not reset previously passed parameters to toBuffer', (done) => {
+    const image = sharp(fixtures.inputJpg);
+    image.toBuffer({ resolveWithObject: true }).then((obj) => {
+      image.toBuffer().then((buff) => {
+        assert.strict.equal(Buffer.isBuffer(buff), true);
+        assert.strict.equal(typeof obj, 'object');
+        done();
+      });
+    });
+  });
+});
--- a/test/unit/trim.js
+++ b/test/unit/trim.js
@@ -41,6 +41,21 @@ describe('Trim borders', function () {
      });
  });

+  it('single colour PNG where alpha channel provides the image', () =>
+    sharp(fixtures.inputPngImageInAlpha)
+      .trim()
+      .toBuffer({ resolveWithObject: true })
+      .then(({ data, info }) => {
+        assert.strictEqual(true, data.length > 0);
+        assert.strictEqual('png', info.format);
+        assert.strictEqual(916, info.width);
+        assert.strictEqual(137, info.height);
+        assert.strictEqual(4, info.channels);
+        assert.strictEqual(-6, info.trimOffsetLeft);
+        assert.strictEqual(-20, info.trimOffsetTop);
+      })
+  );
+
  it('16-bit PNG with alpha channel', function (done) {
    sharp(fixtures.inputPngWithTransparency16bit)
      .resize(32, 32)
@@ -58,6 +73,27 @@ describe('Trim borders', function () {
      });
  });

+  it('Attempt to trim 2x2 pixel image fails', function (done) {
+    sharp({
+      create: {
+        width: 2,
+        height: 2,
+        channels: 3,
+        background: 'red'
+      }
+    })
+      .trim()
+      .toBuffer()
+      .then(() => {
+        done(new Error('Expected an error'));
+      })
+      .catch(err => {
+        assert.strictEqual('Image to trim must be at least 3x3 pixels', err.message);
+        done();
+      })
+      .catch(done);
+  });
+
  describe('Invalid thresholds', function () {
    [-1, 'fail', {}].forEach(function (threshold) {
      it(JSON.stringify(threshold), function () {
--- a/test/unit/util.js
+++ b/test/unit/util.js
@@ -118,6 +118,13 @@ describe('Utilities', function () {
        assert.strictEqual(true, sharp.format.raw[direction].stream);
      });
    });
+    it('vips format supports filesystem only', function () {
+      ['input', 'output'].forEach(function (direction) {
+        assert.strictEqual(true, sharp.format.vips[direction].file);
+        assert.strictEqual(false, sharp.format.vips[direction].buffer);
+        assert.strictEqual(false, sharp.format.vips[direction].stream);
+      });
+    });
  });

  describe('Versions', function () {
Author	SHA1	Message	Date
Lovell Fuller	d0feb4156c	Release v0.23.3	2019-11-17 15:42:07 +00:00
Lovell Fuller	0d1278dade	Improve C++ linting, move exceptions inline	2019-11-14 22:06:38 +00:00
Lovell Fuller	1b401b1195	Add FreeBSD to CI via Cirrus #1953	2019-11-14 21:55:20 +00:00
Lovell Fuller	11daa3b4d1	Tests: flatten to mid-grey before generating fingerprint	2019-11-14 13:18:14 +00:00
Lovell Fuller	88a3919ce0	Docs refresh	2019-11-14 11:32:49 +00:00
Lovell Fuller	c41b87303d	Ensure trim op supports image-in-alpha #1597	2019-11-14 11:29:45 +00:00
Lovell Fuller	833aaead56	Ensure modulate can co-exist with other colour ops #1958	2019-11-11 22:16:28 +00:00
Lovell Fuller	ff98d2e44a	Docs: using custom binaries with prebuild-install	2019-11-07 20:00:03 +00:00
Lovell Fuller	fcf05f608a	Changelog entry for #1952	2019-11-07 19:59:18 +00:00
Pouya Eghbali	9baf38db44	Allow compilation of v0.23.x on FreeBSD and variants (#1952 )	2019-11-06 23:11:44 +00:00
Lovell Fuller	69050ef1c8	Add funding link to libvips' Open Collective	2019-11-05 21:51:14 +00:00
Lovell Fuller	b35b9f7850	Ensure Travis does not cache builds #1948	2019-11-01 16:17:36 +00:00
Lovell Fuller	500ae97cac	Changelog entry for #1921	2019-11-01 16:15:02 +00:00
Brendan Kennedy	d5b7040557	Ensure tile overlap option works as expected (#1921 )	2019-10-30 20:02:07 +00:00
Lovell Fuller	ca52894651	Release v0.23.2	2019-10-28 18:21:11 +00:00
Lovell Fuller	4009acdd30	Docs: support added for Node.js 13	2019-10-28 18:19:33 +00:00
Lovell Fuller	147c93ecd3	Tests: increase coverage for jpeg-related logic	2019-10-27 20:03:10 +00:00
Lovell Fuller	8e04e4b07f	Tests: add coverage for tiff quality option	2019-10-27 19:54:23 +00:00
Lovell Fuller	e7413ea1e5	Tests: increase coverage for metadata-related logic	2019-10-27 19:32:48 +00:00
Lovell Fuller	220bb03a32	Switch from excl npmignore to incl package.json files	2019-10-27 18:22:10 +00:00
Lovell Fuller	20f512fe5f	Bump dependency patch versions	2019-10-26 23:15:41 +01:00
Lovell Fuller	efb3523eaa	Remove duplicate validation from resize background	2019-10-26 23:13:12 +01:00
Lovell Fuller	2f2276e091	Changelog entries for #1924 #1932	2019-10-26 22:53:39 +01:00
Paul Neave	08a6597626	Add background option to tile output operation (#1924 )	2019-10-25 14:30:33 +01:00
Nicolas Stepien	d82a6ee4fc	Add Node.js 13 to CI (#1932 )	2019-10-23 19:28:19 +01:00
Lovell Fuller	e627f6d68d	Docs: clarify that input 'path' refers to the filesystem	2019-10-05 08:43:40 +01:00
Lovell Fuller	e650f58bd8	Improve error messaging for root/sudo permission problems	2019-10-04 12:14:08 +01:00
Lovell Fuller	5a9b6c8afd	Tighten validation of page/pages constructor options	2019-10-03 16:41:32 +01:00
Lovell Fuller	075771d1e9	Improve error messaging for 404 errors on non-standard platforms	2019-10-03 15:32:15 +01:00
Lovell Fuller	4fcf091fef	Bump tar dep (appears to be non-breaking despite major increment)	2019-10-03 15:30:56 +01:00
Marc Bornträger	0e66454fe4	Docs: Simplify Alpine Linux info, uses 3.10 instead of edge	2019-10-01 12:00:38 +01:00
Lovell Fuller	aa3ce760bb	Release v0.23.1	2019-09-26 10:19:06 +01:00
Lovell Fuller	ba46ad1fd9	Docs: mention removal of metadata in output methods	2019-09-25 16:56:52 +01:00
Lovell Fuller	11214bab5d	Bump tar dependency to ensure minipass >=2.8.6	2019-09-25 14:31:54 +01:00
Lovell Fuller	d87c289b4a	Update results from latest benchmark test run	2019-09-25 14:16:51 +01:00
Lovell Fuller	af45c03b6f	Bump benchmark dependencies ahead of a perf test run	2019-09-25 12:03:16 +01:00
Lovell Fuller	7d6fadce6b	Ensure promise-based benchmark test is fairer Real-world code will register a catch handler	2019-09-25 12:01:43 +01:00
Lovell Fuller	6b560f7a85	Remove imagemagick-native module from benchmarks Unmaintained, does not compile with newer ImageMagick and Node	2019-09-25 10:13:45 +01:00
Lovell Fuller	5d4221460d	Docs: Add more prominent link to libvips	2019-09-24 10:53:33 +01:00
Lovell Fuller	d42c383992	Add link from GitHub to libvips OpenCollective	2019-09-24 10:49:52 +01:00
Lovell Fuller	9c7f6fcb2b	Replace deprecated URL parser Fix up various linter errors	2019-09-22 22:46:48 +01:00
Lovell Fuller	14af0bda61	Regenerate flatten-rgb16-orange test expectation, reduce threshold	2019-09-21 20:01:15 +01:00
Raboliot le gris	fb5c393fbd	Allow instance reuse with differing toBuffer options (#1860 )	2019-09-08 14:35:16 +01:00
Lovell Fuller	69fe21a7ec	Ensure invalid resize width/height as options throw #1817	2019-08-16 21:21:12 +01:00
Lovell Fuller	da4e05c118	Better validation and test coverage for background colours	2019-08-16 20:37:17 +01:00
Lovell Fuller	e4333ff6b0	Changelog entry, credit and doc update for #1835	2019-08-14 20:17:31 +01:00
Andargor	4ae8999f62	Add premultiplied option to composite operation (#1835 )	2019-08-14 19:01:23 +01:00
Lovell Fuller	3fa91bb4ce	Ensure image >= 3x3 before attempting trim operation See https://github.com/libvips/libvips/issues/1392	2019-08-13 21:34:49 +01:00
Lovell Fuller	23b2e541ab	Changelog entry for #1834	2019-08-12 21:45:29 +01:00
Julian Aubourg	5bfcf61a6f	Allow use of heic/heif identifiers with toFormat (#1834 )	2019-08-12 21:36:56 +01:00
Lovell Fuller	0778c112a9	Ensure sharp.format.vips is present and correct #1813	2019-08-12 21:25:10 +01:00
Lovell Fuller	2c300754a7	Expand issue templates to direct towards installation	2019-07-31 16:48:32 +01:00