I'll soon (I hope) have an issue: I've created a map for my rpg, as things really are, for GM reference. This "gm map" is really what the world is. Done in Photoshop.

To give some of it to my players, I would like to distort it, more or less given the quality of the map they buy/found, or their geography knowledge. Quite like the medieval or renaissance maps of our world. So something that will displace the geometry of the map, without being too obvious or unnatural.

Does anyone have an idea on how best to do that? It can be destructive it doesn't matter, but it need to be easily done again and again when I export some more of my GM map.