Estimating Shape and Reflectance of Surfaces by Color Image Analysis

Sato and Ikeuchi[4] proposed an interesting method of shape recovery based on color image analysis which requires the object to be enclosed in a spherical diffuser. In this paper, we improve the method to relax this restriction. Like [4], we use the dichromatic-reflection model to separate the specular reflection and the diffuse reflection. In our method, the point light source is enclosed by a diffuser and is moved to different specified locations by a robot arm. This changes the lighting geometry and a new radiance function of the source is derived. On the whole, this is an improvement on the inconvenient set up of [4]. The capability of our method is verified by real experiments. A simulation package is also developed to test the efficacy of our approach for objects of different sizes under various forms of lighting geometry.