color correction for 40 year old Agfa tranparency

[david72645 (David)]

I have some 40 year old Agfa 2 1/4 that is faded. I’m new to processing. What is the best place to start? What tool is best for this (automatic or manual)? All the photos seem to bee faded in the same way so if I could come up with a formula I assume I could make a preset. Perhaps this has already been done by someone and all I need is their settings.

[yasuo (Ohnishi, Yasuo)]

It is not RawTherapee command, however equalize command in GIMP is very effective for restoration of faded film images.

Fading film image color restoration effect of equalize command in GIMP 2.10

Hi, GIMP has equalize command (histogram equalization algorithm) which purpose is thought as increasing the global contrast of images. However it has fading film image color restoration effect, which is little known, I think, because it is only side effect of this command algorithm. Adobe Photoshop also has same name command, however it does not have the color restoration effect. I suppose the reason is that Photoshop’s algorithm is “improved” for original purpose of this command. Therefor, GIM…

There are some restoration sample images in following thread.

Family archives, Saint-Tropez, 1959, before it became too fashionable

This is a slide shot with a slide duplicator. Strong red cast. Can’t tell the film type without opening the mount, which I prefer not to do. The original picture: [Diapo000166-lowres] A first shot at it (convenient French flag in front): [SaintTrop-59-lowres] The raw file: Diapo000165.cr2 (14.5 MB) These files are licensed Creative Commons, By-Attribution, Share-Alike. Brigitte Bardot may or may not be hidden in the picture.

[Terry (Terry Pinfold)]

I do a lot of my photo restoration work in GIMP. Auto levels can sometimes work miracles on faded colors. The equalize command works in a similar fashion. Maybe you could put an image in the PlayRaw category and people could try different softwares and techniques to get the result you like.

[Zbyma72age]

I suggest you give it a try:
It also works properly in Windows 11

stongey/PhotoRestore/blob/master/Windows/restore4.0A.exe

Readme

STANDALONE WINDOWS APP FOR RESTORING FADED SLIDES AND PRINTS

NOTE - This is an experimental (alpha) release that has been tested only on Windows 7, so far.

Your experience may vary. Please report issues.

The instructions for running the program are:

• Make a new working folder anywhere on your computer.
• Copy (not move) into it some of the faded pictures you want to restore.
• In the working folder, make a subfolder named ’restored’ (without the ’ ’ quotes) to contain the results.
• Download the file restore4.0A.exe from GitHub.
• Copy it into the working directory.
• Double click on the program restore4.0A.exe.
• Put the kettle on - the calculation is very slow but the results should appear in the ’restored’ directory.
  It has been tested on Windows 7; I have no idea if it will work in Windows 10.

When viewing the resulting images using the default Windows image viewer, they appear dark and saturated. This appears to be caused by the Windows image viewer not the restoration software. They images look all right with other viewing software.

[yasuo (Ohnishi, Yasuo)]

I tried his restoration programs and they are not bad. Also he made GIMP plugin version of his programs and their algorithm are different each other.

However, for restoration of very faded film images, I believe equalize command of GIMP is most powerful tool.

[Zbyma72age]

I recommended it because he wrote:
“I’m new to processing.”