They might be impossible to compress using RLE-based mechanisms, but the theoretical possibility is there. The noise range for the pixels is not 0-255, so the i

They might be impossible to compress using RLE-based mechanisms, but the theoretical possibility is there. The noise range for the pixels is not 0-255, so the image has less entropy than a fuly random one and thus should be compressable. I am imagining something like a "base layer" with averaged brightness + arithmetic coding for differences might do it.