Yeah, that is the problem we didnt see before. At first sign it seems to work , but with that issue. To remove “1 until end” we need to subtract as I said before. We needed 96 to 128 (maybe grayscaled or white), the rest values black=0.
The grayscale filter is not problem. That´s resolved with your first formula, but including that small issue … “1 until end”.
The new problem is a new scenario.
Extract a mask for only the Brighness values of the image. In photoshop is named HSB (Brightness). In UE4 is named HSV, and goes from 0 to 1.
The image of the Island I uploaded before has 2 splatmaps in the same file. We know to extract the diferent channels for RGBCMYK and asing them to landscape_layer_blend(height), but we need also the other values from brightness.