Color reflection models on materials

Abstract

An important role of surface spectral reflectance is to supply the physical basis for object color perception and surface identification. The behavior of the reflectance function depends on the surface materials. In this paper we propose color reflection models for a variety of objects based on the analysis of the reflected light spectra from the object surfaces and their surface spectral reflectances. First, we test the adequacy of the standard dichromatic reflection model. The model assumes that the reflected light is composed of two components of specular and diffuse reflections and that the specular reflection is constant over the visible wavelength. The experimental results show that the standard model is adequate for many materials, but it is inadequate for metals composed of only specular reflection, and for some paper and cloth. Next, we analyze the surface spectral reflectances of these inadequate materials to supply a proper model. The paper and cloth can be approximated with the generalized dichromatic reflection model with chromatic specular reflection. Furthermore, metals can be approximated with the dichromatic reflection model with two specular reflection components. Thus, it is shown that color reflection for most objects is expressed in three kinds of dichromatic reflection models.