Shape from Shading algorithms exist, but how well they work depends on the nature of your surface and how much quality you require in your output. As...
I've got a bunch of contracts and request documents to fill out and send to Lightening Source as a possible short run or POD printer - they do both....
For modern maps, I prefer a vector approach, with Illustrator or Inkscape. Modern life is far less about the terrain that a fantasy or historical map...
The resolution is a little low on the sampling (it looks like nobody in Nevada was consulted, for example). If they would just data mine the Echelon...
Eh, my skills and style probably match your needs, but I'm way too busy to do other work, and I actually develop my own feudal Japanese dark fantasy...
Saving for CS4!, Corel Painter X, Fractal Terrains, Wilbur, Anything and Everything Else!
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Dollhouse Syndrome = The temptation to turn a map into a picture, obscuring the goal of the image with the appeal of cute, or simply available, parts. Maps have clarity through simplification.