Range Image Segmentation Based on Differential Geometry: A Hybrid Approach

One of the most significant problems arising out of range data analysis is image segmentation. This correspondence describes a hybrid approach to the problem, where hybrid refers to a comhination of both regionand edge-based considerations. The range image of 3-D objects is divided into surface primitives which are homogeneous in their intrinsic differential geometric properties and do not contain discontinuities in either depth or surface orientation. The method is based on the computation of partial derivatives which are obtained by a selective local hiquadratic surface fit. Then by computing the Gaussian and mean curvatures, an initial region-based segmentation is obtained in the form of a curvature sign map. Two additional initial edge-based segmentations are also computed from the partial derivatives and depth values: jump and roof edge maps. The three image maps are then combined to produce the final segmentation. Experimental results were obtained for both synthetic and real range data of polyhedral and curved