<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<script>
function draw() {
var c = document.getElementById('c').getContext('2d');
var img = document.getElementById("img");
c.fillStyle = 'red';
c.fillRect(0, 0, 200, 200);
c.rect(0, 0, 100, 100);
c.clip();
c.drawImage(img, 0, 0, 200, 200);
}
</script>
</head>
<body onload="draw();">
<canvas id='c' width='200' height='200'></canvas>
<img id="img" src="image_green-16x16.png" style="display:none">
</body>
</html>