imagemin-gifsicle

Imagemin plugin for Gifsicle. This is a fork of imagemin-gifsicle with additional options.

Install

$ npm install @xanderfrangos/imagemin-gifsicle

Usage

const imagemin = require('imagemin');
const imageminGifsicle = require('imagemin-gifsicle');

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

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

API

imageminGifsicle(options?)(buffer)

Returns a Promise<Buffer> with the optimized image.

options

Type: object

interlaced

Type: boolean
Default: false

Interlace gif for progressive rendering.

optimizationLevel

Type: number
Default: 1

Select an optimization level between 1 and 3.

The optimization level determines how much optimization is done; higher levels take longer, but may have better results.

1. Stores only the changed portion of each image.
2. Also uses transparency to shrink the file further.
3. Try several optimization methods (usually slower, sometimes better results)

colors

Type: number

Reduce the number of distinct colors in each output GIF to num or less. Num must be between 2 and 256.

lossy

Type: number
Default: 20

Alter image colors to shrink output file size at the cost of artifacts and noise. Lossiness determines how many artifacts are allowed; higher values can result in smaller file sizes, but cause more artifacts.

colorMethod

Type: string
Default: diversity

Determine how a smaller colormap is chosen. diversity, the default, is xv(1)’s diversity algorithm, which uses a strict subset of the existing colors and generally produces good results. blend-diversity is a modification of this: some color values are blended from groups of existing colors. median-cut is the median cut algorithm described by Heckbert.

ditherMethod

Type: string
Default: floyd-steinberg

Specify a dithering algorithm with the optional method argument. The default, floyd-steinberg, uses Floyd-Steinberg error diffusion. This usually looks best, but can cause animation artifacts, because dithering choices will vary from frame to frame. Gifsicle also supports ordered dithering algorithms that avoid animation artifacts. The ro64 mode uses a large, random-looking pattern and generally produces good results. The o3, o4, and o8 modes use smaller, more regular patterns. The ordered mode chooses a good ordered dithering algorithm. For special effects, try the halftone modes halftone, squarehalftone, and diagonal. Some modes take optional parameters using commas. The halftone modes take a cell size and a color limit: halftone,10,3 creates 10-pixel wide halftone cells where each cell uses up to 3 colors.

resize

Type: string
Format: widthxheight

Resize the output GIF to the given width and height. If width or height is an underscore _, that dimension is chosen so that the aspect ratio remains unchanged.

resizeMethod

Type: string
Default: mix

Set the method used to resize images. The sample method runs very quickly, but when shrinking images, it produces noisy results. The mix method is somewhat slower, but produces better-looking results. The default method is currently mix.

Other methods include sample, box, mix, catrom, mitchell, lanczos2, lanczos3.

resizeColors

Type: number

Allow Gifsicle to add intermediate colors when resizing images. Normally, Gifsicle’s resize algorithms use input images’ color palettes without changes. When shrinking images with very few colors (e.g., pure black-and-white images), adding intermediate colors can improve the results.

buffer

Type: Buffer

Buffer to optimize.