I have a specific, rather obvious method of modify colors in an image in my mind, but can't find the tools in common graphic programs such as Gimp or Photoshop to do it with.
Color space can be thought of as a three-dimensional vector space, with one natural base being red, green and blue.
For each pair of color triplets there is exactly one linear map from the first triplet to the second triplet of colors. (If the color triplets consist of colors with distinct hues anyway.)
Now I'd like to have that linear transformation, defined by those six colors, applied to each pixel in my image.
Can Gimp, Photoshop or any other known tool do that?
Is there a common buzzword for that kind of operation?
PS: For the benefit of others, Joojaas answer can also be implemented in Gimp by doing: