Color Constancy

We would rather eat a banana that looks yellow than one that looks green because the banana's color appearance carries reliable information about its ripeness. In general, color appearance is [Page 254]a useful percept because it provides reliable information about object identity and state. When we search for our car in a large parking lot, we rely on color to pick out likely candidates; our driver's licenses list the color of our eyes and hair for identification; we detect that a friend is embarrassed by the blush of his or her face.

For color appearance to provide useful information about objects, it must correlate with properties intrinsic to objects and be stable against transient features of the environment in which the objects are viewed, such as ...