Color blindness and a color human visual system model

A physiologically motivated human color visual system model which represent s visual information with one brightness component (A) and two chromatic co mponents (C-1 and C-2) is used to create stimuli for testing the color perc eption of deuteranomalous trichromats. Two experiments are performed. Using simple ramp patterns, the first experiment finds that three deuteranomalou s trichromat test subjects can distinguish variations only in the C-2 compo nent of the color vison model. This finding is further tested in the second experiment, a set of paired comparison preference tests. Two altered versi ons of each of three natural color images are prepared by setting either on e of the color components to a constant over the full image. Pairs of an or iginal and a distorted image are presented to the test subjects, and they a re asked to indicate which image they prefer. Constant C-1 images are frequ ently preferred over originals, while constant C-2 images are described as appearing monochrome to the deuteranomalous trichromats. These experimental results indicate that the C-1 channel is severely attenuated in the deuter anomalous trichromat test subjects, and that nearly all their color sensati on is mediated hy the C-2 channel of the color vision model.