Shape from shading for non-Lambertian surfaces from one color image

In this paper a robust approach of shape recovery from one color image for non-Lambertian surfaces is presented. A dichromatic reflection model is assumed to describe the color hybrid surface. An extended light source model is used so that both specular and diffuse reflection components can be detected simultaneously in one image. The color of the light source is assumed different from that of the object. This is a very mild restriction which can almost be satisfied. Using color information, regions of the image with hybrid reflection can be segmented from regions with only diffuse reflection. A new reflectance map for non-Lambertian surface is developed so that surface shape can be inferred using the shape from shading technique. For regions with only diffuse reflection, the conventional reflectance map for Lambertian surface can be used. Some results based on real experiments and simulations are presented to show the validity of our method.