So I have DEMs for my project, created in Photoshop and processed in Wilbur. These days I am using GIS software with these too, but I have a problem with the scale: Wilbur allowed me to span the terrain as I needed, but GIS software reads the resulting file as "1 shade of grey = 1 metre". These are 16-bit files, so a mountain that should be 1,300 m is coming out as 19,000.

This sounds like a problem that would be easy to fix, but searching for anything on editing DEMs, all I can find is people saying, "You can't edit a DEM," "You don't need to edit a DEM," and "Are you crazy? Why would you need to change the scale on a DEM?!?" I'm sure that must make sense for real world DEMs, but it's not much help for fantasy DEMs.

Does anyone have a solution to this problem? What software would I need, or what would I need to do to set the elevation scale on a DEM file?


A little addendum about what I want to do: having the DEM display with proper elevation values makes it easy to measure elevation at any point. (Of course, I can already do this measurement in Wilbur.) But I also want to create contour lines using QGIS. This is actually pretty easy, and I don't necessarily even need the right elevation values in order to do this — it would be easy enough to work out a multiplier to turn 19,000 into 1,300 — but it would be even better if the values were correct to begin with.