<!DOCTYPE html>
<html>
<head>
<script>

function boom()
{
  var a = document.getElementById("a");
  var b = document.getElementById("b");
  a.getContext('2d').createPattern(b, 'no-repeat');
}

</script>
</head>

<body onload="boom();">
<canvas id="a" width="61" height="26"></canvas>
<canvas id="b" width="611" height="439807"></canvas>
</body>

</html>