image-loader

Image loader module for webpack

Minify PNG, JPEG, GIF and SVG images with imagemin

Issues with the output should be reported on the imagemin issue tracker.

Install

$ npm install image-webpack-loader --save-dev

libpng issues

Installing on some versions of OSX may raise errors with a missing libpng dependency:

Module build failed: Error: dyld: Library not loaded: /usr/local/opt/libpng/lib/libpng16.16.dylib

This can be remedied by installing the newest version of libpng with homebrew:

brew install libpng

Usage

Documentation: Using loaders

In your webpack.config.js, add the image-loader, chained with the file-loader:

loaders: [
    {
        test: /\.(jpe?g|png|gif|svg)$/i,
        loaders: [
            'file?hash=sha512&digest=hex&name=[hash].[ext]',
            'image-webpack?bypassOnDebug&optimizationLevel=7&interlaced=false'
        ]
    }
]

If you want to use pngquant or mozjpeg you must use the json options notation like this:

loaders: [
  {
    test: /\.(gif|png|jpe?g|svg)$/i,
    loaders: [
      'file?hash=sha512&digest=hex&name=[hash].[ext]',
      'image-webpack?{optimizationLevel: 7, interlaced: false, pngquant:{quality: "65-90", speed: 4}, mozjpeg: {quality: 65}}'
    ]
  }
];

You can also use a configuration section in your webpack config to set global options for the loader, which will apply to all loader sections that use the image loader.

{
  module: {
    loaders: [
      {
        test: /\.(gif|png|jpe?g|svg)$/i,
        loaders: [
          'file?hash=sha512&digest=hex&name=[hash].[ext]',
          'image-webpack'
        ]
      }
    ]
  },

  imageWebpackLoader: {
    mozjpeg: {
      quality: 65
    },
    pngquant:{
      quality: "65-90",
      speed: 4
    },
    svgo:{
      plugins: [
        {
          removeViewBox: false
        },
        {
          removeEmptyAttrs: false
        }
      ]
    }
  }
}

With webpack 2 now supporting query object syntax, you can also write as

loaders: [
  {
    test: /\.(gif|png|jpe?g|svg)$/i,
    loaders: [
      'file-loader',
      {
        loader: 'image-webpack-loader',
        query: {
          progressive: true,
          optimizationLevel: 7,
          interlaced: false,
          pngquant: {
            quality: '65-90',
            speed: 4
          }
        }
      }
    ]
  }
]

Comes bundled with the following optimizers:

• gifsicle — Compress GIF images
• mozjpeg — Compress JPEG images
• optipng — Compress PNG images
• svgo — Compress SVG images
• pngquant — Compress PNG images

imagemin(options)

Unsupported files are ignored.

options

Options are applied to the correct files.

optimizationLevel (png)

Type: number Default: 3

Select an optimization level between 0 and 7.

The optimization level 0 enables a set of optimization operations that require minimal effort. There will be no changes to image attributes like bit depth or color type, and no recompression of existing IDAT datastreams. The optimization level 1 enables a single IDAT compression trial. The trial chosen is what. OptiPNG thinks it’s probably the most effective. The optimization levels 2 and higher enable multiple IDAT compression trials; the higher the level, the more trials.

Level and trials:

1. 1 trial
2. 8 trials
3. 16 trials
4. 24 trials
5. 48 trials
6. 120 trials
7. 240 trials

imageminMozjpeg(options)

Returns a promise for a buffer.

options

quality

Type: number

Compression quality. Min and max are numbers in range 0 (worst) to 100 (perfect).

progressive

Type: boolean
Default: true

false creates baseline JPEG file.

interlaced (gif)

Type: boolean Default: false

Interlace gif for progressive rendering.

svgo (svg)

Type: object Default: {}

Pass options to svgo.

bypassOnDebug (all)

Type: boolean Default: false

Using this, no processing is done when webpack 'debug' mode is used and the loader acts as a regular file-loader. Use this to speed up initial and, to a lesser extent, subsequent compilations while developing or using webpack-dev-server. Normal builds are processed normally, outputting optimized files.

imageminPngquant(options)

options.floyd

Type: number Default: 0.5

Controls level of dithering (0 = none, 1 = full).

options.nofs

Type: boolean Default: false

Disable Floyd-Steinberg dithering.

options.posterize

Type: number

Reduce precision of the palette by number of bits. Use when the image will be displayed on low-depth screens (e.g. 16-bit displays or compressed textures).

options.quality

Type: string

Instructs pngquant to use the least amount of colors required to meet or exceed the max quality. If conversion results in quality below the min quality the image won't be saved.

Min and max are numbers in range 0 (worst) to 100 (perfect), similar to JPEG.

options.speed

Type: number Default: 3

Speed/quality trade-off from 1 (brute-force) to 10 (fastest). Speed 10 has 5% lower quality, but is 8 times faster than the default.

options.verbose

Type: boolean Default: false

Print verbose status messages.

Inspiration

• gulp-imagemin
• file-loader
• imagemin-pngquant

License

MIT (http://www.opensource.org/licenses/mit-license.php)