I’ll do that. I was erring on the side of more smoothing only because I assumed it mattered how closely the test and reference images were identically aligned.
If I understand correctly, I could shuffle the pixels of both images into a random order and get the same result.
Have you found a smoothing number that works best when the sources just aren’t cropped or aspect-ed identically?
0.05 usually works for me if the two sources really look different.