Run results for: OffscreenCanvas GetImageData

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.81 Safari/537.36

Browser: Chrome 94

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Normal	29.4 Ops/sec
OffscreenCanvas	15.2 Ops/sec

Script Preparation code:

let canvas = document.createElement("canvas")
let width = 3460;
let height = 2160;
canvas.width = width;
canvas.height = height;
let canvas2 = new OffscreenCanvas(width, height)
let ctx = canvas.getContext('2d')
let ctx2 = canvas2.getContext('2d')
let imageData = new ImageData(width,height);
ctx.putImageData(imageData,0, 0);
document.body.append(canvas)
ctx2.putImageData(imageData,0 ,0)
window.ctx = ctx;
window.ctx2 = ctx2
window.width = width;
window.height = height;

Tests:

Normal
ctx.getImageData(0,0, width, height) let imageData = new ImageData(1,1); ctx.putImageData(imageData,5,5);
OffscreenCanvas
ctx2.getImageData(0,0, width, height) let imageData = new ImageData(1,1); ctx2.putImageData(imageData, 5,5);

Run results for: OffscreenCanvas GetImageData

OffscreenCanvas GetImageData

Normal

OffscreenCanvas