Surface descriptions from stereo and shading

Surface reconstruction from stereo and shape-from-shading have both been discussed extensively in the literature. In this paper methods that attempt to supplement stereo with analysis of shading, are reviewed, with comments on their robustness. Theoretical results on uniqueness in shape from shading are presented, and on the difficulty of estimating surface shape with local intensity operators. Preliminary experiments based on the method of Koenderinck and van Doorn, for analysing variation of shading with viewpoint, are reported. It is concluded that there is a variety of techniques for deriving qualitative shape information, which might be sufficiently robust for use in computer vision systems. © 1985.