I have no idea how they were created, or where the embedded values came from, or why they're such odd dimensions!
However it has helped me figure out that when they're used it does bicubic interpolation of the heights which is nice to know so I'll document that and probably factor out the code (already done on my branch).
Anyway this leads me onto some questions for people who're interested in the subject namely:
- What format do we want to use? 16-bit TIFF uncompressed seems common.
- Should it come with a specification file? That defines scaling, min heights, etc, separate from the data/image format.
- Is there a good argument for having a 16-bit TIFF -> Custom format converter?
- Can anyone think of anything else I've missed?
I've been getting heightmaps from here:
https://astrogeology.usgs.gov/search/ma ... l_200mp_v2
But beware they are HUGE files, I've had to use ImageMagick to resize them from the command line using:
Code: Select all
convert Mars_MGS_MOLA_DEM_mosaic_global_463m.tif -resize 10% -depth 16 Mars10pc.tif