<!DOCTYPE HTML>
<html>
<body>
<div style="-moz-transform:scale(0.5); -moz-transform-origin:top left; border:10px solid black; border-radius:20px;">
<canvas width="100" height="100" id="c" style="display:block"></canvas>
<script>
var c = document.getElementById("c");
var ctx = c.getContext("2d");
ctx.fillStyle = "yellow";
ctx.fillRect(0, 0, c.width, c.height);
</script>
</body>
</html>