From [R, G, B] to Surface Reflectance: Computing Color Constant Descriptors in Images

This paper addresses the issue of color constancy, which is the the perceptual abi l i ty of the human visual system to assign the same colors to objects under different l ight ing conditions. We propose a method, based on finite-dimensional linear models of reflectance and i l luminat ion, which allows the transformation [R,G,B] images into color constant images. In contrast to previous work, we show that good results can be obtained using a 3-receptor system and some knowledge about the spectral properties of natural materials and i l luminants. In the method developed, an estimate of i l luminant in the scene is computed, which allows the computat ion of color constant descriptors of the pixel values in the image. In addi t ion, we show a method of computing the actual reflectances of the materials in the scene out of the computed color descriptors.