metalsmith-minify-png v1.0.1

metalsmith-minify-png

A metalsmith plugin for minifying PNG images.

This plugin minifies all of the PNG images found in Metalsmith files by using the Pngquant and Zopflipng programs. If Pngquant and Zopflipng are not installed, then minification of Pngquant and Zopflipng images will be skipped.

Installation

npm install metalsmith-minify-png

Usage

To use this plugin, simply add it to the existing plugins in your Metalsmith source file or include it in the Metalsmith JSON file:

JavaScript

const Metalsmith = require('metalsmith');
const minifyPng = require('metalsmith-minify-png');

Metalsmith(__dirname)
  .use(minifyPng())
  .build((err, files) => {
    if (err) { throw err; }
  });

JSON

{
  "plugins": {
    "metalsmith-minify-png": {}
  }
}

Options

You can pass options to metalsmith-minify-png with the Javascript API or CLI. The options are:

• pattern: optional. Only PNG files that match this pattern will be processed. Accepts a string or an array of strings. The default is **/*.png.
• usePngquant: optional. If true, will use the pngquant program to minify PNGs (however, if Pngquant is not installed, will skip this option). Accepts a boolean value. The default is true.
• useZopflipng: optional. If true, will use the zopflipng program to minify PNGs (however, if Zopflipng is not installed, will skip this option). Accepts a boolean value. The default is true.
• speed: optional. The level of speed specified in the --speed argument for Pngquant that sets the level of optimization. Accepts a string or a number. The default is null (no speed level will be set).
• strip: optional. If true, will strip the optional PNG metadata. Accepts a boolean value. The default is false.
• iterations: optional. Set the number of iterations to use with Zopflipng. Accepts a number. The default is 15.

pattern

Only files that match this pattern will be processed for PNG minification. So this Metalsmith JavaScript configuration or metalsmith.json:

JavaScript

const Metalsmith = require('metalsmith');
const minifyPng = require('metalsmith-minify-png');

Metalsmith(__dirname)
  .use(minifyPng({
    pattern: 'blog/**/*.png',
  }))
  .build((err, files) => {
    if (err) { throw err; }
  });

JSON

{
  "source": "src",
  "destination": "build",
  "plugins": {
    "metalsmith-minify-png": {
      "pattern": "blog/**/*.png"
    }
  }
}

Would only process PNG files within the ./src/blog folder, because the pattern is relative to your source folder. See multimatch for further details.

usePngquant

If set to true, will use the pngquant program to minify PNG files. So this Metalsmith JavaScript configuration or metalsmith.json:

JavaScript

const Metalsmith = require('metalsmith');
const minifyPng = require('metalsmith-minify-png');

Metalsmith(__dirname)
  .use(minifyPng({
    usePngquant: true,
  }))
  .build((err, files) => {
    if (err) { throw err; }
  });

JSON

{
  "source": "src",
  "destination": "build",
  "plugins": {
    "metalsmith-minify-png": {
      "usePngquant": true
    }
  }
}

Would process PNG files using Pngquant.

useZopflipng

If set to true, will use the zopflipng program to minify PNG files. So this Metalsmith JavaScript configuration or metalsmith.json:

JavaScript

const Metalsmith = require('metalsmith');
const minifyPng = require('metalsmith-minify-png');

Metalsmith(__dirname)
  .use(minifyPng({
    useZopflipng: true,
  }))
  .build((err, files) => {
    if (err) { throw err; }
  });

JSON

{
  "source": "src",
  "destination": "build",
  "plugins": {
    "metalsmith-minify-png": {
      "useZopflipng": true
    }
  }
}

Would process PNG files using Zopflipng.

speed

The speed parameter sets the level of optimization when running Pngquant program. So this Metalsmith JavaScript configuration or metalsmith.json:

JavaScript

const Metalsmith = require('metalsmith');
const minifyPng = require('metalsmith-minify-png');

Metalsmith(__dirname)
  .use(minifyPng({
    speed: null,
  }))
  .build((err, files) => {
    if (err) { throw err; }
  });

JSON

{
  "source": "src",
  "destination": "build",
  "plugins": {
    "metalsmith-minify-png": {
      "speed": null
    }
  }
}

Would disable the --speed parameter for Pngquant (the default value 4 will be used).

strip

The strip parameter determines if optional metadata will be removed when running Pngquant program. So this Metalsmith JavaScript configuration or metalsmith.json:

JavaScript

const Metalsmith = require('metalsmith');
const minifyPng = require('metalsmith-minify-png');

Metalsmith(__dirname)
  .use(minifyPng({
    strip: false,
  }))
  .build((err, files) => {
    if (err) { throw err; }
  });

JSON

{
  "source": "src",
  "destination": "build",
  "plugins": {
    "metalsmith-minify-png": {
      "strip": false
    }
  }
}

Would disable the --strip parameter for Pngquant (no optional metadata will be removed).

iterations

The iterations parameter determines how many iterations will be used with the Zopflipng program. So this Metalsmith JavaScript configuration or metalsmith.json:

JavaScript

const Metalsmith = require('metalsmith');
const minifyPng = require('metalsmith-minify-png');

Metalsmith(__dirname)
  .use(minifyPng({
    iterations: 15,
  }))
  .build((err, files) => {
    if (err) { throw err; }
  });

JSON

{
  "source": "src",
  "destination": "build",
  "plugins": {
    "metalsmith-minify-png": {
      "iterations": 15
    }
  }
}

Would use 15 iterations with the Zopflipng program.

License

AGPLv3