Chromatic Adaptation for Dichromatic Illumination with Uneven Luminance Distribution

Past studies on chromatic adaptation mainly focused on single illuminant conditions, thereby fostering the development of various CAT models. Several recent works on this topic have extended the application of von Kries CAT to dichromatic illuminants, but they fail to account for the effect of spatial luminance distribution on the adaptation state due to the lack of visual data. To further generalize the CAT model for dichromatic illuminants, a series of achromatic matching experiments have been conducted under dichromatic illuminants varying in spatial configuration and luminance distribution for two color pairs. The study revealed that the equivalent illuminant tended to be biased by the illuminant with a higher luminance level and shifted toward the illuminant with increasing luminance, particularly in cases of sharp-transitioned dichromatic illuminants. In addition, a comprehensive chromatic adaptation model for dichromatic illuminants was derived from the collected visual data by taking the spatial distribution of luminance and chromaticity into account.