imagemin-mozjpeg

What is imagemin-mozjpeg?

The imagemin-mozjpeg npm package is a plugin for Imagemin that compresses JPEG images using the MozJPEG encoder. It is designed to reduce the file size of JPEG images while maintaining high visual quality, making it ideal for web optimization and other scenarios where image size is a concern.

What are imagemin-mozjpeg's main functionalities?

Basic JPEG Compression

This feature allows you to compress JPEG images using the default settings of the MozJPEG encoder. The code sample demonstrates how to use imagemin-mozjpeg to compress all JPEG images in the 'images' directory and save the optimized images to the 'output' directory.

const imagemin = require('imagemin');
const imageminMozjpeg = require('imagemin-mozjpeg');

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

Custom Quality Compression

This feature allows you to specify the quality of the JPEG compression. The code sample demonstrates how to use imagemin-mozjpeg with a custom quality setting of 75, which balances file size and image quality.

const imagemin = require('imagemin');
const imageminMozjpeg = require('imagemin-mozjpeg');

(async () => {
    await imagemin(['images/*.jpg'], {
        destination: 'output',
        plugins: [
            imageminMozjpeg({ quality: 75 })
        ]
    });
    console.log('Images optimized with custom quality');
})();

Progressive JPEG Compression

This feature enables progressive JPEG compression, which allows images to be displayed incrementally as they are downloaded. The code sample demonstrates how to use imagemin-mozjpeg to compress images with the progressive option enabled.

const imagemin = require('imagemin');
const imageminMozjpeg = require('imagemin-mozjpeg');

(async () => {
    await imagemin(['images/*.jpg'], {
        destination: 'output',
        plugins: [
            imageminMozjpeg({ progressive: true })
        ]
    });
    console.log('Images optimized with progressive compression');
})();

Other packages similar to imagemin-mozjpeg

imagemin-jpegtran

The imagemin-jpegtran package is another Imagemin plugin that compresses JPEG images using jpegtran. It is known for its lossless compression capabilities, which means it can reduce file size without any loss in image quality. Compared to imagemin-mozjpeg, imagemin-jpegtran is better suited for scenarios where maintaining the original image quality is crucial.

imagemin-jpegoptim

The imagemin-jpegoptim package is an Imagemin plugin that uses jpegoptim for JPEG compression. It offers both lossy and lossless compression options and is highly configurable. Compared to imagemin-mozjpeg, imagemin-jpegoptim provides more flexibility in terms of compression options and is suitable for users who need fine-grained control over the compression process.

imagemin-webp

The imagemin-webp package is an Imagemin plugin that converts images to the WebP format, which is known for its superior compression and quality characteristics compared to JPEG. While it does not directly compete with imagemin-mozjpeg in terms of JPEG compression, it offers an alternative for users looking to switch to a more modern image format for better performance and quality.

README

imagemin-mozjpeg

Imagemin plugin for mozjpeg

Install

$ npm install imagemin-mozjpeg

Usage

import imagemin from 'imagemin';
import imageminMozjpeg from 'imagemin-mozjpeg';

(async () => {
	await imagemin(['images/*.jpg'], {
		destination: 'build/images',
		plugins: [
			imageminMozjpeg()
		]
	});

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

API

imageminMozjpeg(options?)(buffer)

Returns a Promise<Buffer>.

options

Type: object

quality

Type: number

Compression quality, in range 0 (worst) to 100 (perfect).

progressive

Type: boolean
Default: true

false creates baseline JPEG file.

targa

Type: boolean
Default: false

Input file is Targa format (usually not needed).

revert

Type: boolean
Default: false

Revert to standard defaults instead of mozjpeg defaults.

fastCrush

Type: boolean
Default: false

Disable progressive scan optimization.

dcScanOpt

Type: number
Default: 1

Set DC scan optimization mode.

• 0 One scan for all components
• 1 One scan per component
• 2 Optimize between one scan for all components and one scan for 1st component plus one scan for remaining components

trellis

Type: boolean
Default: true

Trellis optimization.

trellisDC

Type: boolean
Default: true

Trellis optimization of DC coefficients.

tune

Type: string
Default: hvs-psnr

Set Trellis optimization method. Available methods: psnr, hvs-psnr, ssim, ms-ssim

overshoot

Type: boolean
Default: true

Black-on-white deringing via overshoot.

arithmetic

Type: boolean
Default: false

Use arithmetic coding.

dct

Type: string
Default: int

Set DCT method:

• int Use integer DCT
• fast Use fast integer DCT (less accurate)
• float Use floating-point DCT

quantBaseline

Type: boolean
Default: false

Use 8-bit quantization table entries for baseline JPEG compatibility.

quantTable

Type: number

Use predefined quantization table.

• 0 JPEG Annex K
• 1 Flat
• 2 Custom, tuned for MS-SSIM
• 3 ImageMagick table by N. Robidoux
• 4 Custom, tuned for PSNR-HVS
• 5 Table from paper by Klein, Silverstein and Carney

smooth

Type: number

Set the strength of smooth dithered input. (1...100)

maxMemory

Type: number

Set the maximum memory to use in kilobytes.

sample

Type: string[]

Set component sampling factors. Each item should be in the format HxV, for example 2x1.

buffer

Type: buffer

Buffer to optimize.