08-04-2019, 10:02 AM
This is a games texture, a map? http://boundingboxsoftware.com/materialize/ - no linux version and the video tutorials are too long 
so guessing at requirements.
Taking the posted RGB jpeg and a color cube analysis Colors -> Info -> Color Cube Analysis, only shows 86 shades. Did this originally come from a greyscale image?
As examples of differences, taking (roughly) the lightest and darkest shade in the jpeg, A gradient in 32 bit RGB has 477 shades but so does a 8 bit RGB so it is not bit depth.. Convert to greyscale gives something like the jpeg and down to 69 shades and banding. example: https://i.imgur.com/7onoIbt.jpg
Try the previous mentioned fixes, also a gaussian blur might help but you are still stuck with those 86 shades of grey and you need more. You probably need to go back to beginnings and look at how you are making the map in the first place.
so guessing at requirements.Taking the posted RGB jpeg and a color cube analysis Colors -> Info -> Color Cube Analysis, only shows 86 shades. Did this originally come from a greyscale image?
As examples of differences, taking (roughly) the lightest and darkest shade in the jpeg, A gradient in 32 bit RGB has 477 shades but so does a 8 bit RGB so it is not bit depth.. Convert to greyscale gives something like the jpeg and down to 69 shades and banding. example: https://i.imgur.com/7onoIbt.jpg
Try the previous mentioned fixes, also a gaussian blur might help but you are still stuck with those 86 shades of grey and you need more. You probably need to go back to beginnings and look at how you are making the map in the first place.