Enhancing color representation for anomalous trichromats on CRT monitors

Abstract

Cathode ray tube (CRT) displays are probably the most widely used color imaging devices, and include TV sets and computer monitors. Although the CRT color representations are adequate for people with normal color vision, color-deficient users would be expected to experience problems of color identification and discrimination with CRT images, just as they do with “real life” objects. A theoretical method is proposed for combining specially designed filters with the unique spectral emission characteristics of the CRT phosphors for enabling certain types of color anomalous trichromats to see the color of the displayed images as a person with normal color vision would see the CRT. Given the spectral emission curves of the CRT phosphors and the sensitivity curve of the color-deficient eye, the relative sensation levels of the L, M, and S cones can be calculated. Applying an optimized color filter and a neutral adaptation background illumination, the L, M, and S sensation ratios can be modified to achieve the normal values. A numerical method is presented to design the filter transmission curve and to verify the L, M, and S cone sensation ratios. © 2000 John Wiley & Sons, Inc. Col Res Appl, 26, S273–S276, 2001