A novel approach to photometric motion

Photometric motion, as introduced by Pentland, employs both reflectance map and optical flow information for the estimation of shape from image sequences of dynamic scenes. It is thus a coupled geometric/photometric process, similarly as the disparity-based photometric stereo, which combines matching and image irradiance equations for surface reconstruction from photometric stereo input. Exploiting the parallel between those two processes, we have arrived at a novel formulation for the photometric-motion shape estimation problem, whose distinctive feature is that of being based on the irradiance change, due to the motion, at a given point in the image plane, and not, as in Pentland's proposal, at a fixed location on the moving surface. We are thus able to obtain an easily implementable procedure which yields good-quality shape estimates for rotating surfaces, and which can also be extended to single-input shape reconstruction.