COLOR APPEARANCE - THE EFFECTS OF ILLUMINATION AND SPATIAL PATTERN

The color we perceive at each point in an image depends on information spread across the three spatial arrays of cone photoreceptors. I desc ribe experiments aimed at clarifying how information is integrated acr oss the spatial arrays to yield a color experience. We have found that changes of color appearance due to changes of the ambient illuminatio n and the pattern's spatial frequency can be described by using a simp le set of optical and neural transformations. Each transformation can be thought of as having two parts. First, the transformation converts the color representation into a new coordinate frame that is independe nt of the image contents. Second, the transformation scales the neural responses in the new coordinate frame by a gain factor that depends o n the image contents.