I’m not sure I understand the point of dividing the channels by the normalised IR image.
Can you elaborate a bit? how does it work? the result of the division is the final clean image?
Back to my films: maybe they were not all E6, I’m not sure: I’m working right now on slides from my parents, but I remember mixing them up as kid so some rolls could even be Kodachrome! The film is now many km away from me and I cannot check. So you may be right and I’m actually working on a script which will be good for Kodachrome.
See an example of what I have also on rolls which I know for sure are E6:
Back to the previous experiment, I made a mistake: I used “binary” mode of pointcloud which doesn’t give a proper idea of the clouds.
I repeated with type “1 accumulation” and I got much more reasonable correlation between channels and IR:
Now the red channel is always the one with the best correlation (sharper and longer cloud).
I can work from here, but I’m not sure when I’ll have time. First I have to think about the algorithm.