/*
Check which dimension has the smallest distance, making it 
suitable for a straight resize.  The other dimension can then 
be padded to restore the ratio.
*/
if(($src_width - $dest_width) >= ($src_height - $dest_height))
{
	$dest_height = ($dest_width/$src_width) * $src_height;
}
else
{
	$dest_width = ($dest_height/$src_height) * $src_width;
}