$sourceCanvas = document.createElement("canvas");
$sourceCanvas.width = 100;
$sourceCanvas.height = 100;
$sourceContext = $sourceCanvas.getContext("2d");
$destCanvas = document.createElement("canvas");
$destCanvas.width = 200;
$destCanvas.height = 200;
$destContext = $destCanvas.getContext("2d");
$destContext.drawImage($sourceCanvas, 0, 0, 100, 100, 0, 0, 200, 200);