Hi all! Sorry for replying late but I was busy working on some much better idea.    For now, @drunkapple: sorry, I don't understand very well this thing about voids. Are these the areas for which there is no data? I don't see any gaps (voids?) in the data I downloaded but I see that some familiar mountainous areas of Athens are a bit deformed... Is this what you are talking about? Also, my script does not perform any scaling. It just translates the elevation data to pixel colors... Anyway, I found out that Global Mapper does all this stuff much better. The application I am preparing is based on Global Mapper's output. Just be patient...   @SirRaunaldi: I am still stuck with XP. If you can make corrections, please, be my guest. Otherwise, jump to Global Mapper.   @algis242: Please tell me which subtile asc file (srtm_xx_xx_x_x.asc) did you use?    I'll be back soon