Hello eveyone,
Thanks a lot indeed for your help.
Usually, for my Leica pictures, I only need to match their overall brightness.
Many fungi have spores that have no color and I prefer to have the final images with the same brightness. The same goes for nematodes (little “worms”).
In my previous example, with the Fusicoccum spores, one pciture was much darker than the other.
With Gimp I adjust these different images with the Curves tool (by changing the brigthness).
With G’MIC I have tried the “transfer color advanced” and the “Clut from after before layers filters” (to create a LUT table) but I found them poorly working compared to the Gimp curves tool where this brightness modification is extremely quick to perform by hand.
I prefer to work with the GUI.
No batch transformation is needed since I have only a few images to work with.
Needless to say, I was not sure about the correct G’MIC filter to pick for my use-case because there are hundreds of them to try 