I am trying to invert the lightness of an image using gimp, but I can't find a way do do it. I should say that I am not really familiar with Gimp, but need to use it to work on GIF images.
It seems that Gimp only offers to work on the Value in HSV. So if I tried to invert the Value, a dark red will be converted to a bright red, whereas I would like it to be converted to a light red...
Attached is an example of what I am talking about.
Does someone see a way to achieve this using GIMP ?