Lightness modification method considering chromaticity loss for dichromats

In recent years, with the development of media equipment, color images have been extensively applied in various domains. However, people with dichromatic or anomalous trichromatic vision have difficulty discriminating the colors that common trichromatic vision would distinguish. To improve image visibility for dichromats, a lightness modification method considering the chromaticity loss was proposed in this study. First, the chromaticity loss was defined for dichromats. Subsequently, an objective function including the chromaticity loss was constructed. To focus on color pairs with a large chromaticity loss, a weight was introduced into the objective function. The objective function was then minimized to obtain output images. Finally, the effectiveness of the proposed method was verified through experiments, which indicated that the proposed method could maintain naturalness for normal trichromats and improve recognition for dichromats.