Practical guides and mathematical foundations for color science, color spaces, and image processing. Tristimulus Values & Color Matching Functions Color perception is based on three types of cone cells in the human eye. The CIE defined standard color matching functions $\bar{x}(\lambda)$, $\bar{y}(\lambda)$, …

Non-linear filter excellent for removing salt-and-pepper noise while preserving edges. Definition Replace each sample with the median of its neighborhood: $$ y[n] = \text{median}{x[n-k], \ldots, x[n], \ldots, x[n+k]} $$ Implementation 1from scipy import signal, ndimage 2import numpy as np 3 4# 1D median filter …