We are using the Natural Earth 2 map as a test file, and it's worked swimmingly. Unfortunately, our archaeologist has given us a satellite image (not distributable) in the form of a geotiff that does not seem renderable by the application (after appropriate reprojection).
How do we, using grass or command line osgeo tools, inspect the various file settings of our Natural Earth 2 map and then impose those settings onto the geotiff we have. Unfortunately, our team is rather newbish when it comes to sophisticated geotiff manipulation, so specific steps are encouraged.