A Computational Approach to Color Illusions

Tri-stimulus theory of color perception is not able to justify effectively some well known perception phenomena as color illusions and color constancy. Retinex theory, by Land and McCann, grounds color perception on a color space based on three lightness computed as relative reflectance along multiple exploration paths of the perceived scene. This paper considers in a new light Retinex theory, as a theory which tries to justify not only color constancy but also illusions arising from simultaneous contrast configurations. An improvement to Retinex computational model is presented in the paper, which selects Retinex computation paths by approximating a brownian path. The algorithm has been tested not only on traditional Mondrian patches, but also on natural pictures and photographs and on typical color illusion patches. The examples demonstrate the ability of the model to emulate human color perception behavior.