Lightness Modification of Color Image for Protanopia/Deuteranopia in RGB Color Space

In this paper, we propose a method which converts an original image into the image that does not give a strange impression to trichromatic vision and is easy for dichromatic vision to discriminate colors by modifying only the lightness in the RGB color space, where the color gamut can be easily grasped. In the proposed method, the lightness modification is executed by adding the red-green component multiplied by a coefficient derived from an optimization problem into the lightness component for each pixel. The optimization problem is defined as the minimization of the lightness difference between pixels considering the difference in color. The effectiveness of the proposed method is illustrated through comparison with conventional methods.