This paper is concerned with estimation of the reflectance map and its use in surface shape estimation by a method that combines stereo and shading information. There are many advantages to the integrated approach. However, shape from shading algorithms are limited in their applicability by the assumption of idealized reflectance and lighting models involving many preset or hard to estimate parameters. In this paper, it is shown that the difficulties involved in estimation of the reflectance function and light source distribution can be eliminated through direct estimation of the reflectance map using adaptive polynomial models. The reflectance map estimate is used with a surface estimate provided by stereo in an integrated approach to surface shape estimation.>

The authors deal with estimation of the light source distribution and its use in surface shape estimation by the methods of stereo and shading. There are many advantages to integrating stereo and shading information. However, shape from shading algorithms are limited in their applicability by the assumption of overly simplistic models of the light source distribution. A more complete representation is described in which the lighting model makes use of multiple fixed point sources located at infinity. Methods of estimating the model parameters are developed, and a method of estimating the surface shape given the albedo and source distribution is presented. The shading algorithm is combined with a stereo algorithm in an integrated approach that is designed to handle albedo variations through the use of color images.>