Heightmap and Information loss

[Lionhardt]

Hey, I have a problem with editing and re-importing heightmaps. Whenever I re-import a heightmap after editing it looks like it the image has gone through a compression process, as the terrain will be like terraced or layered.

The file types, the heightmap goes through from exporting to re-importing is the following: RAW -> PNG -> (XCF) -> PNG -> RAW


Does anybody know, where the compression and therewith information loss might happen?


(If you wonder, why I go through all these formats: I am running a Linux machine, where I do my editing with gimp and use Photoshop on another machine for converting to and from RAW, because gimp does not support 16 bit graphics, which is required for the RAW files for the map editor. But I don't use the latter machine for editing, because it's a laptop with a very small screen...)


Edit: I just had an idea, where the problem might lie... I each time rotate the map by 45 degrees, because the whole heightmap can be reconstructed from an 8th of the it. So I need to rotate it to cut out that 8th slice, mirror it, rotate the whole thing back and then mirror it two more times. I guess the loss comes from the rotating... is that possible?

[Deep_]

(If you wonder, why I go through all these formats: I am running a Linux machine, where I do my editing with gimp and use Photoshop on another machine for converting to and from RAW, because gimp does not support 16 bit graphics, which is required for the RAW files for the map editor. But I don't use the latter machine for editing, because it's a laptop with a very small screen...)

The answer lies in your quote. If you put a file into gimp, which as you say does not support 16bit, it comes out as a 8bit map. The folllowing import in photoshop and the converting to a 16 bit raw does not make up for the fact that your source map is 8 bit. Its like a 460p screenshot of a 1080p video, its still 460p. 8 bit maps are just unusable for hightmaps!
So you have to find a workflow without gimp.

[Lionhardt]

Oh!! That makes sense, lol. Thanks! I just wonder why the map editor tutorial then suggest GIMP for heightmap editing though.

[Deep_]

Oh!! That makes sense, lol. Thanks! I just wonder why the map editor tutorial then suggest GIMP for heightmap editing though.

an image manipulation program, to edit/mirror your heightmaps and texture layers, e.g. Adobe Photoshop, GIMP, Corel Paint Shop Pro, or paint.net.

I guess Gimp is a laternetive when its comes to textures, not when it comes to hightmaps though.