DEM creation problems

[waldronate]

You can't just span correctly in Wilbur before export?

I know what you mean about the GIS folks, btw. Those real-world data sets are expensive to obtain and you really don't want to muck about with them.

[Thorf]

From what I can see, the problem is that the software I'm using (both QGIS and Geographic Imager) thinks that the DEM is scaled in metres, with the greyscale 16-bit colour range corresponding to metres.

I have already spanned the terrain to my desired range in Wilbur, with a pure white marker to indicate the top elevation, as per your recommendation. (Thanks!) It has been working great for me like this.

There are various problems with treating these images as DEM files, though. For a start, Wilbur outputs PNG or MDR, whereas the GIS programs tend to need something else. I have chosen TIF, since it's easily editable in Photoshop, and can hold geographic information too. I'm guessing that the DEM scale information for a regular DEM is encoded in the file's metadata somewhere, but Wilbur's PNGs don't contain that sort of metadata. And since real world DEMs are not generated by everyday users, there doesn't seem to be an option to add or change this metadata.

It's a bit of a conundrum.