NodeJS Animated gif resizing

Question

I am trying to resize an animated gif using NodeJS. I need it to stay animated after resizing.

My app is currently using Sharp to resize other images, but it appears to not support exporting animated gifs.

If possible I would like to find an npm package that doesn't rely on another external software like *Magick. It would be awesome if it supported streams as well.

Answer 1

I don't know about any native npm package, but you can use gifsicle.

Gifsicle is a command-line tool for creating, editing, and getting information about GIF images and animations.

This is a good article about resizing animated gifs using gifsicle: https://davidwalsh.name/resize-animated-gif

Example 1: I used gifsicle module to install the gifsicle's binary file:

const { execFile } = require('child_process');
const gifsicle = require('gifsicle');

console.time('execute time');

// You can use these options for resizing:
// --scale 0.5
// --resize-fit-width 300
// --resize-fit-height 200
// --resize 300x200
execFile(gifsicle, ['--resize-fit-width', '300', '-o', 'output.gif', 'input.gif'], err => {
  console.timeEnd('execute time');

  if (err) {
    throw err;
  }

  console.log('image resized!');
});

Example 2: Use the spawn method to get a readable stream:

const fs = require('fs');
const { spawn } = require('child_process');
const gifsicle = require('gifsicle');

console.time('execute time');

const stream = spawn(gifsicle, ['--resize-fit-width', '300', 'input.gif']);

stream.on('close', () => {
  console.timeEnd('execute time');

  console.log('image resized!');
});

stream.stdout.pipe(fs.createWriteStream('output.gif'));