Toward a Surface Sketch

摘要

This paper reports progress toward the development of a representation of significant surface changes in dense depth maps. The authors call the representation the Surface Primal Sketch by analogy with representations of intensity changes, image structure, and changes in curvature of planar curves. They describe an implemented program that detects, localizes, and symbolically describes: steps, where the surface height function is discontinuous; roofs, where the surface is continuous but the surface normal is discontinuous; smooth joins, where the surface normal is continuous but a principal curvature is discontinuous and changes sign; and shoulders, which consist of two roofs and correspond to a step viewed obliquely. The performance of the program on range maps of objects of varying complexity is illustrated.