I have a before/after image pair with pixel transformations only (for example, grayscale, or a hue shift. No blur, border, sharpen, etc.). I'm trying to find a function such that for every pixel
(r, g, b) in the original image,
f(r, g, b) = (r', g', b'),
(r', g', b') being the pixel in the "after" image.
I was thinking about a polyfit function, but I couldn't find one that works in 3D.
I'd appreciate any help with this, or another method of achieving what I need.