Do you have the sourcecode for ISA_MapGen.exe? I've been working on a very similar project for Garry's Mod, and I'd like to see how yours works since mine takes about twice the time with about the same amount of data. The data is sampled differently and shows population instead of terrain, but the image is created the same way. EDIT: Nevermind, what I'm doing is probably slower since I don't know the minimum and maximum coordinates beforehand, and I have to read through the data twice.