I think storing maps as images is quite common actually for simple games not made in a game engine that handles maps.<p>You can also use the drawn map as a template, and add random details (random variants of each tile). Also, you'll quickly find you want to use more sophisticated autotiling which handles multiple tile types meeting, and special cases. Here's an article about autotiling by defining rulesets which goes into more detail: <a href="http://www.squidi.net/three/entry.php?id=166" rel="nofollow">http://www.squidi.net/three/entry.php?id=166</a>