Color constancy: the role of image surfaces in illuminant adjustment

Abstract

Previous studies on color constancy have found that the color appearance of a test surface varies both as a function of the illumination in the image and as a function of the image surfaces. To what extent these two effects interact is investigated here. To address this issue theoretically, a restrictive von Kries model is formulated that assumes that the scaling of the cone signals in response to an illuminant change does not depend on image surfaces. Subjects saw CRT simulations of illuminated surfaces and, for a number of different illuminants and surface collections, adjusted a test light so that it appeared achromatic and had a certain brightness. Consistent with previous studies, the settings showed a high degree of illuminant adjustment and also showed an adjustment to the surfaces in the image. The proposed von Kries model provided a good, although not perfect, description of the data, thus indicating that the illuminant adjustment was largely the same under the different surface collections. These results together with those from several previous studies suggest that image surfaces play only a minor role in the illuminant adjustment of our visual system.