Scene Depth Profiling Using Helmholtz Stereopsis

Abstract

Helmholtz stereopsis is a 3D reconstruction technique, capturing surface depth independent of the reflection properties of the material by using Helmholtz reciprocity. In this paper we are interested in studying the applicability of Helmholtz stereopsis for surface and depth profiling of objects and general scenes in the context of perspective stereo imaging. Helmholtz stereopsis captures a pair of reciprocal images by exchanging the position of light source and camera. The resulting image pair relates the image intensities and scene depth profile by a partial differential equation. The solution of this differential equation depends on the boundary conditions provided by the scene. We propose to limit the illumination angle of the light source, such that only mutually visible parts are imaged, resulting in stable boundary conditions. By simulation and experiment we show that a unique depth profile can be recovered for a large class of scenes including multiple occluding objects.