A Polarimetric Approach to Shape Understanding of Glossy Objects

Abstract

A polarimetric method is proposed to find surface normals, which will help the 3-D shape understanding of glossy objects. Attention is directed to the fact that glossy objects are characterized by conspicuous specular reflection, which has a certain polarizational property as a function of the incident angle and the refractive index of the material. The relation is formulated between the local normal and the polarizational parameters. The Stokes parameters are used to express the state of polarization. As to several materials preliminary measurements are done to examine for utility of polarizational information to finding local normals. The proposed method will be effective in extracting geometrical parameters from glossy objects whose gloss occurs on dielectric surfaces such as plastics, lacquered items, polished paper and so on.