[IMPROVEMENT] Diff between pixels

[dmiroshnyk]

Moved from another issue

Why diff between pixels is calculated like (pixel2RGB - pixel1RGB)? For example, we have pixel2 - white. Diff vs pixel1 depends on pixel1 RGB color. So, diff vs red pixel will be less than vs blue. I don't understand the reason of this. For example, if I convert my image with google and change all red colors to blue and ask to recalculate diff (let's imagine the bug is fixed) - the diff percentage return another value which looks having no sense because the result file will look identically. IMHO, the diff between single pixel should be normalized to 0 (no diff) or 1(diff) and formula should look like: (<# of all different pixels> / <# of all pixels>) * 100. What do you think about it?

[scp-WFZ]

@romankh3 Hello~, I'd like to work on this issue.