Get a pixel from HTML Canvas?

Question

Is it possible to query a HTML Canvas object to get the color at a specific location?

Answer 1

You can use i << 2.

const data = context.getImageData(x, y, width, height).data;
const pixels = [];

for (let i = 0, dx = 0; dx < data.length; i++, dx = i << 2) {
    pixels.push({
        r: data[dx  ],
        g: data[dx+1],
        b: data[dx+2],
        a: data[dx+3]
    });
}