Hello,
I am a complete newbie in the process of backing up family photos from all kinds of formats. There are many Kodak photo prints from the 80’s with a more or less scratched surface which appear cyan.
(My current process is Epson v600 → Silverfast 9SE RAW 48bit → Gimp (levels/curves/cleanup) → 24bit png.)
Below is an example of such a photo. Are there any tricks for repairing this kind of damage? Any help is appreciated!
Hi,
For this kind of editing, I wrote a CTL script, not for GIMP, but for ART, which you can find at the following link.
If you would like to give us CC license of this image and are interested in editing it with ART, I would be happy to show you an example of the editing.
In Gimp the color balance option lets you tweak the colors of the shadows, midtones, and highlights separately. This can be very useful with images like this. I am a little perplexed about what to do about the scratches. I wonder if taking a photograph with a polarizing filter might manage the reflections from the scratches? Probably not.
Thank you, Yasuo!
Feel free to give it a try with the image, I would be happy to see what you can achieve!
I didn’t know about that feature, that is really helpful!
That’s what the forum is for. Good luck with your scans.
The basic concept of my CTL script is similar to GIMP’s color balance. However, my CTL script gives you more precis control over the editing area and the amount of color editing.
Bravo Yasuo!
Yesterday I looked at that photo and my first thought was: impossible to repair. So I’m really surprised about your very good result. 
Thank you for your compliment. 
Awesome, thank you Yasuo!
Always amazed to see what can be done with damaged photos. I will try and replicate what you did with your script. 
Thinking a bit more about this issue, maybe it is worth trying some kind of polarizer?
Does anyone have experience with polarizing film on a flatbed? The reason I think this would work is that the scratches only affect the reflective surface, the image itself is intact so the printed photos look good when held at the right angle.
What kind of polarizing film would have the greatest change of working?
I didn’t try it, however I think it needs to attach polarizer in front of the scanner’s lens and scanner modification may be required.
I think it is easier to take a photo of the print with a camera with polarizer.
When I mentioned a polarizer I was referring to using a digital camera with a polarising filter and lights placed at a suitable angle to minimize reflections. I am unaware of any polarizing method that would work on a flat bed.
Finally remembered what I did for another similar that had green all over it.
This time I went a little different way. I moved the hue slider until the cyan looked like a dark purple. Then I ran GMIC’s ‘unpurple’ filter on it.
Get’s rid of the cyan but you may have to touch it up a little after to put some colour back into it
