Wasm Image Decoder

Decodes images using Rust’s image crate compiled to WebAssembly. By default it uses 4 threads (though some decoders are single-threaded) since it doesn’t seem to get much faster if I add any more. You can edit mod.js to change the number of threads.

Works in the browser and should work in Deno when this PR lands and 1.10.0 is released (around May 2021).

Demo

import decode from "https://deno.land/x/wasm_image_decoder@v0.0.3/mod.js";
let buf = await fetch("https://i.imgur.com/LYVUrUf.jpg").then(r => r.arrayBuffer());
let result = decode(buf); 
console.log(result); // {width, height, data} where data is a Uint8Array array of RGBA values like [R,G,B,A,R,G,B,A,R,G,B,A,...]

Build

wasm-pack build --target=web --out-dir=wasm
# For now a manual change needs to be made to workerHelper.no-bundler.js as described here: https://github.com/GoogleChromeLabs/wasm-bindgen-rayon/issues/6#issue-867938231