Transparent surface modeling from a pair of polarization images

Abstract

We propose a method for measuring surface shapes of transparent objects by using a polarizing lter. Generally, the light re ected from an object is partially polarized. The degree of polarization depends upon the incident angle which, in turn, depends upon the surface normal. Therefore, we can obtain surface normals of objects by observing the degree of polarization at each surface point. Unfortunately, the correspondence between the degree of polarization and the surface normal is not one to one. Hence, to obtain the correct surface normal, we h a ve to solve the ambiguity problem. In this paper, we i n troduce a m e t h o d t o s o l v e the ambiguity b y comparing the polarization data in two objects, i.e., normal position and tilted with small angle position. We also discuss the geometrical features of the object surface and propose a method for matching two sets of polarization data at identical points on the object surface.

A Combinatorial Transparent Surface Modeling from Polarization Images

“…Despite recent advances in opaque surface modeling, transparent surface modeling relatively has not received much attention. Only recently, some prospective techniques for modeling transparent or specular surface based on polarization images have emerged [2][3][4][5]. These techniques, however, commonly face two fundamental difficulties.…”

“…Such light setting (referred to as photometric sampler firstly proposed by Nayar, et al, [6]) has two limitations: it restricts the object's diameter to be sufficiently small compared to the diffuser's diameter and it suffered much from undesirable inter-reflections. The second difficulty, namely the ambiguity problem, is previously solved by introducing other sources of information such as thermal radiation [3], or new view image [2]. The necessity of such additional information that is not readily available leads to even more impractical and time consuming implementation.…”

“…A more thorough discussion on how to obtain surface normals of transparent surface from polarization analysis of reflected light based on Fresnel equation could be found in [5,2]. When unpolarized light is incident on dielectric transparent surface with an oblique angle, it will be partially polarized.…”

Surface normal estimation of black specular objects from multiview polarization images

“…Miyazaki et al 13 attempted to estimate the surface normal of a diffuse object from a single view. Miyazaki et al 14 used a geometrical invariant to match the corresponding points from two views to estimate the surface normal of a transparent object. Miyazaki and Ikeuchi 15 solved the inverse problem of polarization ray tracing to estimate the surface normal of a transparent object.…”

“…For example, Miyazaki et al, 14 Kadambi et al, 31 and several other researchers used DOP for estimating the surface normal from specular reflection. However, DOP depends on the refractive index and surface roughness.…”