imagemin-optipng

What is imagemin-optipng?

The imagemin-optipng package is a plugin for Imagemin that uses the OptiPNG optimizer to compress PNG images. It helps in reducing the file size of PNG images without losing quality, making it ideal for web developers looking to optimize their images for faster loading times.

What are imagemin-optipng's main functionalities?

Basic PNG Optimization

This code demonstrates how to use imagemin-optipng to optimize PNG images in the 'images' directory and save the optimized images to the 'build/images' directory.

const imagemin = require('imagemin');
const imageminOptipng = require('imagemin-optipng');

(async () => {
    await imagemin(['images/*.png'], {
        destination: 'build/images',
        plugins: [
            imageminOptipng()
        ]
    });
    console.log('Images optimized');
})();

Custom Optimization Level

This code shows how to set a custom optimization level for the PNG images. The optimizationLevel option can be set from 0 to 7, where higher values provide better compression but take more time.

const imagemin = require('imagemin');
const imageminOptipng = require('imagemin-optipng');

(async () => {
    await imagemin(['images/*.png'], {
        destination: 'build/images',
        plugins: [
            imageminOptipng({ optimizationLevel: 3 })
        ]
    });
    console.log('Images optimized with custom optimization level');
})();

Other packages similar to imagemin-optipng

imagemin-pngquant

imagemin-pngquant is another Imagemin plugin that uses the pngquant library to compress PNG images. It is known for providing lossy compression, which can result in smaller file sizes compared to imagemin-optipng, but with a potential loss in image quality.

imagemin-zopfli

imagemin-zopfli is an Imagemin plugin that uses the Zopfli compression algorithm to optimize PNG images. It provides high compression ratios, often better than imagemin-optipng, but at the cost of longer compression times.

imagemin-pngcrush

imagemin-pngcrush is an Imagemin plugin that uses the PNGCrush optimizer to reduce the file size of PNG images. It offers various optimization strategies and can be a good alternative to imagemin-optipng for certain use cases.

README

imagemin-optipng

Imagemin plugin for OptiPNG

Install

$ npm install imagemin-optipng

Usage

const imagemin = require('imagemin');
const imageminOptipng = require('imagemin-optipng');

(async () => {
	await imagemin(['images/*.png'], 'build/images', {
		use: [
			imageminOptipng()
		]
	});

	console.log('Images optimized!');
})();

API

imageminOptipng(options?)(buffer)

Returns a Promise<Buffer>.

options

Type: object

optimizationLevel

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

bitDepthReduction

Type: boolean
Default: true

Apply bit depth reduction.

colorTypeReduction

Type: boolean
Default: true

Apply color type reduction.

paletteReduction

Type: boolean
Default: true

Apply palette reduction.

interlaced

Type: boolean | undefined | null
Default: false

Enable Adam7 PNG interlacing on any images that are processed. Interlaced images look better when they're loaded partially, but usually interlace makes compression less efficient. Set to undefined or null to keep the same interlacing as the input image.

errorRecovery

Type: boolean
Default: true

A reasonable amount of effort will be spent to try to recover as much data as possible of a broken image, but the success cannot generally be guaranteed.

buffer

Type: Buffer

Buffer to optimize.