Color Perception of Aperture Colors Using a Computational Model of the Human Visual System

Abstract

A previously developed model of the human fovea is modified for the analysis of colored stimuli. Whenever possible human and other primate anatomical, electrophysiological, and psychophysical data are incorporated into the computational model. Channels carrying information about color are represented by the summed responses of midget C- and L-type cells. The spectral energy distribution of any colored stimulus produces within the cell types a unique pattern of activities from which the amounts of each of the HUES (i.e., RED, GREEN, BLUE, and YELLOW), WHITENESS, BRIGHTNESS, and SATURATION can be determined. The present analysis is restricted to the fovea, where color vision is optimal and rods are absent or minimal. Psychophysical and model data are in good agreement as to the three attributes of aperture colors i.e., HUE, BRIGHTNESS, and SATURATION. As a result of univariance, information as to the spectral distribution of the stimulus cannot be used, and this creates a problem as to how to normalize colored stimuli to a common set of standards. A method based on normalization of the outputs of the retinal cells to a common WHITE is presented.