Stereo and Specular Reeection

The problem of accurate depth estimation using stereo in the presence of specular reeection is addressed. Specular reeection, a fundamental and ubiquitous reeection mechanism, is viewpoint dependent and can cause large intensity diierences at corresponding points, resulting in signiicant depth errors. We analyze the physics of specular reeection and the geometry of stereopsis which lead to a relationship between stereo vergence, surface roughness, and the likelihood of a correct match. Given a lower bound on surface roughness, an optimal binocular stereo connguration can be determined which maximizes precision in depth estimation despite specular reeection. However, surface roughness is diicult to estimate in unstructured environments. Therefore, trinocular conngurations, independent of surface roughness, are determined such that at each scene point visible to all sensors, at least one stereo pair can produce correct depth. We have developed a simple algorithm to reconstruct depth from the multiple stereo pairs.