ON THE FAST SHAPE RECOVERY TECHNIQUE USING MULTIPLE RING LIGHTS

摘要

A 3-D shape recovery algorithm, based on the hybrid reflectance model and M ring-shaped lights for specular surfaces, is presented in this paper. We derive a radiance as a function of slant angle of a surface point for a given incident angle of a light source in spherical coordinate. To combine multiple information from each source, we also obtain the optimal weighting factors in a mean square error sense. The surface gradient, which is obtained from the slant angle and its contours, is integrated to obtain the depth map. To test the proposed algorithm, we provide the results of computer simulations on the synthetic data such as hemisphere and multiple Gaussian sphere. The experiments provide satisfactory results and robustness against the input noise, which are discussed in this paper. Demonstrating for a real input image, we also apply the proposed algorithm to recover the shape of soldering part of PCB using four ring lights. (C) 1997 Pattern Recognition Society. [References: 12]