Color Appearance in Mesopic Vision and its Modeling

摘要

Mesopic vision describes a range of light levels where vision is mediated by both cones and rods. The color appearance in mesopic vision differs drastically from that in photopic vision, where only cones mediate visual information. We conducted a set of experiments to investigate the change of color appearance under various illuminance levels, ranging from photopic to scotopic via mesopic levels. In the experiments, we measured the corresponding color of color chips under various illuminance levels by a haploscopic color matching. The results showed that the hue of the most color chips changed with illuminance and the manor of the hue shift depended on color, while matching points of all chips approached the area around neutral gray with decrease of the illuminance level. The lightness of matched color decreased with decrease of the illuminance level, however, the lightness for bluish color chips did not decrease much in general and even increased in some cases, which is referred to as the Purkinje shift. Base on these results, we propose a model of color appearance in mesopic vision.