Advice on this tough (?) image cleanup problem

[zqbobs]

I have several old film photographs (examples attached) that were somehow damaged, maybe by water. Although I have considerable experience with image cleanup and enhancement, this problem has me stumped. I am familiar with tools like Photomator (my recent go-to), GraphicConverter, Affinity, Photoshop Elements, GIMP etc. I do not routinely use Adobe Photoshop, but if I had to...

I know manual techniques such as rubber stamp cloning from nearby areas would help, but that would be really laborious. Can anyone offer advice on particular apps and/or an approach to reduce these photo stains? Good task for AI!

 

[OldMacs4Me]

Anything I can think of would involve selecting areas that seem to have similar discoloration and using curves, levels, white balance and/or HSL corrections to bring them closer to what you want. Will probably require a lot of experimentation to get the correct amount of feathering to get a good blend.

This is the sort of thing where AI might be of some use but somehow I have my doubts. Maybe someone who works extensively with AI can suggest a program that could remove some of the labor.

 

[M4th]

Worth a try? Haven't used it myself, let us know if you do.

 

[Slartibart]

did you try e.g. selection by color and then desaturate the areas e.g. in hue? Or using e.g. Gimps' wavelet decomposition basically treating this as some form of blob stain removal - which will probably work at least for the affected sky. This needs as @OldMacs4Me already indicated probably a combination of tools and steps.

If these are scans from old negatives it might be worth trying to put the negative in a diluted acetic acid bath (you can use vinegar essence in distilled water) for 10 minutes at 21Celsius (time and temperature depend a little on how old your negatives are), after that rinse it in distilled water, and hang the negative (strip) on one corner diagonally to dry. Distilled water is key here.

If the observed blobs due to some liquid on the glossy (!) side of a slide or negative you can also try to apply a tiny amount of 98% isopropyl alcohol and using an exquisite lint-free microfiber cloth - e.g., for cleaning lenses - or lint-free cotton swap to carefully remove these. This technique can also be used to clean and reconstitute the emulsion side, but requires even more finesse there.
the alcohol will evaporate in a clean and ventilated environment - when they’ve dried, last step is wiping off the loosened oils, debris, and dust using again a lint-free cloth. the procedure might have to be repeated a few times. Ultimately you end up with a cleaned negative ready for digitization.