Quantitative studies in retinex theory a comparison between theoretical predictions and observer responses to the “color mondrian” experiments

Abstract

Land's Color Mondrian experiments showed that a single wavelength-radiance distribution falling on a point on the retina can generate nearly any color sensation. In Part I we repeated that experiment, quantifying the color sensations for each of the many Mondrian areas. In Part II we show that each area's color sensation correlates with a triplet of reflectances measured with photodetectors having the same spectral sensitivities as the cone pigments in the eye. This result provides a description of what the visual system does, but it does not provide a mechanism for how the visual system can do it because the reflectance measurements required the use of a reflectance standard and unchanging illumination. In Part III we describe a model for color sensations that computes three reflectances from the wavelength-radiance distribution without reflectance or illumination standards: hence, it is able to predict the color sensations seen by the observer. The model is able to predict gray, red. yellow, green and blue sensations associated with areas that send identical wavelength-radiance distributions to the eye.