| dc.description.abstract | This paper reports progress toward the  development of a representation of significant  surface changes in dense depth maps. We  call the representation the Surface Primal  Sketch by analogy with representation of  intensity changes, image structure, and  changes in curvature of planar curves. We  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 principle  curvature is discontinuous and changes sign;  and shoulders, which consists of two roofs  and correspond to a step viewed obliquely.  We illustrate the performance of the program  on range maps of objects of varying  complexity. | en_US |