discretize
Verb
Meaning
(transitive, mathematics, computing) To convert (a continuous space) into an equivalent discrete space, often for the purposes of easier calculation.
(transitive, broadly) To represent (any spectrum of reality) as a set of discrete categories or classes; to categorize (a spectral aspect of reality) by lumping together some of its finer distinctions.
A rainbow truly contains thousands of color values but can usually be discretized by human sentience into bands of primary and secondary colors.