Sorry, meant fixed-point fractional number of course. Transfer function is the nonliner transformation used to more effectively use the limited resolution of i

Sorry, meant fixed-point fractional number of course. Transfer function is the nonliner transformation used to more effectively use the limited resolution of integer values. Most typical is sRGB gamma (luminance ~ (value / 255) ^ 2.2) or Perceptual Quantization (PQ, smpte2084) for HDR videos. If you want to perform filtering in linear domain (i.e. for your color transformations to look natural) you need to linearize the signal.