Curvature consistency improves local shading analysis

Abstract

This paper describes how a surface reconstruction algorithm, based on minimizing the variation of surface curvature, can be used to stabilize and correct the results of local shading analysis. What is novel about this approach is that it is viewpoint independent and applicable to any process that can provide estimates of local surface orientation. The assumptions used in formulating the minimization are derived from standard differential geometry. When applied as a second stage of processing after local shading analysis, the algorithm can recover a close approximation of the true surface orientation under realistic assumptions about image noise. Results are presented that show the performance of the algorithm on synthetic and real data. In particular, they demonstrate how this form of reconstruction can compensate for some of the shape distortion incurred in local shading analysis.