Visual simulating dichromatic vision in CIE space

Dichromatic vision is due to the loss of one of the three cone pigments: the L type in protanopes, the M type in deuteranopes, and the S type in tritanopes. In this paper, we show that the dichromatic vision can be simulated by applying transformation to image in CIE x, y chromaticity space. We base our work on the past experiments on unilateral color blind (color blind in one eye) people which show that for protanopes and deuteranopes the hue of 470 nm and 575 nm stimuli stay the same as that for normal eyes, and for tritanopes the hue of 485 nm and 660 nm are the same as that for normal eyes. We also assume that the curve between these anchored stimuli points and D6500 standard white stimuli in the chromaticity diagram is quadratic. Our method saves the steps for transformation of CIE chromaticity value to uniform chromaticity value or LMS value as required in the previous work and still gets reasonable results.