<!doctype html>
<html>
<body style='margin:0px'>
<img id='sizer'/>
<script>
// The desired size should be specified in the url in the search portion
// like this ?widthDimension:heightDimension.
var unitMatch = '([0-9]+[a-zA-Z]+)';
var searchParser = new RegExp('\\?' + unitMatch + '(?:\\:' +  unitMatch + ')');
var parsedParameters = searchParser.exec(window.location.search);

// Set the sizes.
var elementToSize = document.getElementById('sizer');
var width = parsedParameters[1];
elementToSize.style.width = width;
var height = parsedParameters[2];
elementToSize.style.height = height;
</script>
</body>
</html>