JS Image Oscillator SRC

<canvas id="canv" width="1000" height="1000">
</canvas>
<script>
c = document.getElementById("canv");
var ctx = c.getContext("2d");

id = ctx.createImageData(1000,1000);

function draw() {
var w=c.width;
var h=c.height;
window.requestAnimationFrame(draw);
var r;
for (var p = 4 * (w * h - 4); p>= 4; p -= 4) {
r = Math.random();
id.data[p] = id.data[p+p] = id.data[p+p] = 256 * Math.pow(r, 1.6);
id.data[p++] = 256;
}
ctx.putImageData(id, 0, 0);
}

draw();

</script>