image-optim

Node.js wrapper for image compression algorithms.

• Types
• Patches
  • Overview
• Install
• Usage
  • API
    • imageOptim.optim
    • imageOptim.lint
    • Exit code
      • SUCCESS
      • CANT_COMPRESS
      • DOESNT_EXIST
    • Example
  • CLI
    • Example

Types

• PNG – PNGOUT, Zopflipng, Pngcrush, AdvPng and OptiPNG.

Supporting of other types of images is coming soon.

Patches

You can view all the patches which are applied to the algorithms here.

Overview:

• optipng.patch – adds to OptiPNG the ability to remove RGB components or transparent pixels in RGB+alpha images.

• zopflipng.patch – makes Zopflipng work on Linux.

Install

$ npm install imageoptim

This command will install image-optim and all supported compression algorithms automatically. The installation of the compression algorithms is subscribed in script env-setup.

Usage

API

var imageOptim = require('imageoptim');

imageOptim.optim

Optimizes the given files.

@param {String[]} – a list of paths to files to optimize
@param {Object} – options:

• reporters {String[]} - reporters of the results. flat - writes the results to stdout, html - creates the HTML report of the results in file imageoptim-report.html (default: flat).

@returns {Promise * Object[]} – the information about optimized files:

[{ name: 'file.ext', savedBytes: 12345, exitCode: 0 }]

imageOptim.lint

Checks whether the given files can be optimized further.

@param {String[]} – a list of paths to files to check
@param {Object} – options:

• tolerance {Number} – sets the measurement error in percentages (decimal < 1) or bytes (integer or decimal >= 1) (default: 0).

type	skope	description
percentages	< 1	The file will be considered to be optimized if the percentage of saved bytes after the compression is less than the specified value (0.8 – 80%, 0.01 – 1%, etc)
bytes	>= 1	The file will be considered to be optimized if the number of saved bytes after the compression is less than the specified value (20 – 20 bytes, 100500 – 100500 bytes, etc)

• reporters {String[]} - reporters of the results. flat - writes the results to stdout, html - creates the HTML report of the results in file imageoptim-report.html (default: flat).

@returns {Promise * Object[]} – the information about linted files:

[{ name: 'file.ext', isOptimized: true, exitCode: 0 }]

Exit code

imageOptim.SUCCESS

If a file was processed without errors its exit code will be equal to 0.

imageOptim.CANT_COMPRESS

If a file can not be processed by one of the algorithms its exit code will be equal to 1.

imageOptim.DOESNT_EXIST

If a file does not exist its exit code will be equal to 2.

Example

var imageOptim = require('imageoptim');
 
// optimization
imageOptim.optim(['1.png', '2.png'], { reporters: ['flat', 'html'] })
    .then(function (res) {
        console.log(res);
    })
    .done();
 
// linting
imageOptim.lint(['1.png', '2.png'], {
        tolerance: 0.08,
        // tolerance: 20,
        reporters: ['flat', 'html']
    })
    .then(function (res) {
        console.log(res);
    })
    .done();

CLI

$ imageoptim --help
Node.js wrapper for image compression algorithms
 
Usage:
  imageoptim [OPTIONS] [ARGS]
 
Options:
  -h, --help : Help
  -v, --version : Shows the version number
  -l, --lint : Lint mode
  -t TOLERANCE, --tolerance=TOLERANCE : sets the measurement error in percentages or bytes (default: 0)
  -r REPORTERS, --reporter=REPORTERS : flat or/and html (default: flat)
 
Arguments:
  FILES : Paths to files (required)

REMARK! More information about options lint and tolerance can be found in the API.

Example

$ imageoptim path/to/file1 path/to/file2 --reporter=flat --reporter=html # optimization 
 
$ imageoptim path/to/file --lint --tolerance=0.08 --reporter=flat --reporter=html # linting, tolerance is `8%` 
 
$ imageoptim path/to/file --lint --tolerance=20 # linting, tolerance is `20 bytes`