This'll do! :D
var sprite = new Image(),
sprite.src = "spritesheet.png",
texture = {y: 42, x: 2*14},
ptrn = generatePattern(sprite, texture.x, texture.y);
ctx.fillStyle = ctx.createPattern(ptrn, "repeat");
ctx.fillRect(0, 0, 500, 500);
Thanks to @KeithThomas for linking to http://stackoverflow.com/questions/8761670/multiple-image-patterns-in-2d-context-of-html5-canvashttps://stackoverflow.com/questions/8761670/multiple-image-patterns-in-2d-context-of-html5-canvas