Consideration of degree of chromatic adaptation for reproducing illuminated scenes

Chromatic adaptation is an important mechanism in the human visual system, which affects the perceived color appearance of scenes and objects under the illumination. Recent studies, however, found that the degree of chromatic adaptation was significantly affected by the chromaticities of the adapting condition, which is not characterized in the existing chromatic adaptation transforms and color appearance models. This work was carefully designed to investigate how the degree of chromatic adaptation needs to be considered to reproduce the overall color tone of scenes under the illumination having a wide range of chromaticities. Human observers viewed a scene under 85 light settings, and then adjusted the color appearance of the scene image shown on a smartphone display to match that of the physical scene. The adjustment of the image color appearance was achieved by performing chromatic adaptation transform with different image white points. The results clearly showed how the degree of chromatic adaptation varied with the illuminant chromaticities, and how the image white point should be adjusted to reproduce the color tone of an illuminated scene.