Benchmark.js

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/benchmark/1.0.0/benchmark.min.js"></script>

JavaScript

function test1() {
    const width = 2592 * 2
    const height = 1944 * 2
    const delta = 11
    const array = new Uint8Array(width * height)
    const out = new Uint8Array(width * height)
    for (let y = 0; y < height; y++) {
        let current = 0
        for (let x = delta; x < width; x++) {
            out[y * height + x] = current
            current -= array[y * height + x - delta]
            current += array[y * height + x]
        }
    }
}

function test2() {
    const width = 2592 * 2
    const height = 1944 * 2
    const delta = 11
    const array = new Uint8Array(width * height)
    const out = new Uint8Array(width * height)
    for (let y = 0; y < height; y++) {
        let current = 0
        let idx = y * height + delta

        for (let x = delta; x < width; x++) {
            out[idx] = current
            current -= array[idx - delta]
            current += array[idx]
            idx++
        }
    }
}

function test3() {
    const width = 2592 * 2
    const height = 1944 * 2
    const delta = 11
    const array = new Uint8Array(width * height)
    const out = new Uint8Array(width * height)
    for (let y = 0; y < height; y++) {
        let current = 0
        let idx = y * height + delta

        for (let x = delta; x < width; x += 4) {
            out[idx] = current
            current -= array[idx - delta]
            current += array[idx]
            idx++
            out[idx] = current
            current -= array[idx - delta]
            current += array[idx]
            idx++
            out[idx] = current
            current -= array[idx - delta]
            current += array[idx]
            idx++
            out[idx] = current
            current -= array[idx - delta]
            current += array[idx]
            idx++

        }
    }
}

function test4() {
    const width = 2592 * 2
    const height = 1944 * 2
    const delta = 11
    const array = new Uint8Array(width * height)
    const out = new Uint8Array(width * height)
   ...