OpenCV: Computer Vision Projects with Python

Curves – bending color space

Curves are another technique for remapping colors. Channel mixing and curves are similar insofar as the color at a destination pixel is a function of the color at the corresponding source pixel (only). However, in the specifics, channel mixing and curves are dissimilar approaches. With curves, a channel's value at a destination pixel is a function of (only) the same channel's value at the source pixel. Moreover, we do not define the functions directly; instead, for each function, we define a set of control points from which the function is interpolated. In pseudocode, for a BGR image:

dst.b = funcB(src.b) where funcB interpolates pointsB dst.g = funcG(src.g) where funcG interpolates pointsG dst.r = funcR(src.r) where ...