Detection of depth and orientation discontinuities in range images using mathematical morphology

A technique for the detection of depth and orientation discontinuities in range images is described. This method uses basic morphological operators to extract these discontinuities from a dense range map. The authors describe how to extract depth discontinuities using the morphological edge operator of J.S.J. Lee et al. (1987) and how to use a top-hat operator to localize the exact positions of these discontinuities. The detection of orientation discontinuities is then discussed in detail. The calculation of a good estimate of the surface normals using anisotropic filtering inhibited at depth discontinuities is demonstrated. Once these estimates of the normals are calculated, operations similar to those used in depth discontinuity detection are used to locate orientation discontinuities at abrupt variations of the surface normals. Experimental results demonstrate computation of the positions of these discontinuities at pixel precision as well as very efficient use of morphological operators to localize abrupt variations in a noisy image signal in less than 1 s using a Datacube image processor