Abstract
Color constancy denotes the ability of human and animals to assign a particular color percept to an object. The light reaching the eye confounds illumination and spectral reflectance of the object, making the recovery of constant object color an ill-posed problem. How good the visual system is at solving this task is still a matter of debate. Depending on the laboratory task and the specific cues available to observers, color constancy was found to reach levels between 20% and 80%. If color constancy were indeed that poor, we would experience frequent color changes of objects in everyday life. This does not seem to be the case. Instead, we take it for granted that objects “have” a color, and we do use color terms to describe objects, e.g. a green scarf.
We propose that the reason for this paradoxical situation is the use of laboratory tasks that systematically underestimate the degree of color constancy. We show that constancy is near perfect when using real objects in a natural task and illumination conditions. Our laboratory task was chosen to replicate the role of color constancy in everyday life. Participants were asked to bring a personal object that had for them a well-defined color that they were confident they could identify. Without the object being present, participants selected the Munsell chip that best represented the color of “their” object. They performed the task first in a room under neutral daylight illumination and in four other rooms that had non-daylight illuminations provided by windows covered with colored filters. In all situations they mostly selected the same colored chip as their match to the absent object, even though the light reaching the eye in each case differed considerably. Our results demonstrate that color constancy under real world conditions is exceptionally good and that previously measured insufficiencies can mainly be attributed to reduced laboratory settings and tasks.
Meeting abstract presented at the 2016 OSA Fall Vision Meeting