Generate Noise on a Canvas
function generateNoise(opacity) {
if ( !!!document.createElement('canvas').getContext ) {
return false;
}
var canvas = document.createElement("canvas"),
ctx = canvas.getContext('2d'),
x, y,
number,
opacityopacity = opacity || .2;
canvas.width = 100;
canvas.height = 100;
for ( x = 0; x < canvas.width; x++ ) {
for ( y = 0; y < canvas.height; y++ ) {
number = Math.floor( (Math.random() * 60));
ctx.fillStyle = "rgba(" + number + "," + number + "," + number + "," + opacity + ")";
ctx.fillRect(x, y, 1, 1);
}
}
document.body.style.backgroundImage = "url(" + canvas.toDataURL("image/png") + ")";
}