REGISTERING RANGE VIEWS OF MULTIPART OBJECTS

We present a method to compute the interframe transformation between two range image views of complex multipart objects. No exact feature matching is attempted and no initial approximate transformation is provided. The method is naturally decomposed into two stages of initial estimation and final refinement of the transformation. A hierarchical triangulation-based surface representation provides an efficient way to select the control points at which the alignment of the two surfaces is to be evaluated. This representation also permits the selection of a manageable number of initial transformations among which at least one is to be in the parametric neighborhood of the actual transformation. Previous techniques are compared and their adaptation into an integrated method makes it possible to go beyond the identified limitations. Experimental results show that the computed transformation between two views of a complex multipart object may provide angles of rotation within a fraction of a degree of the actual ones. (C) 1995 Academic Press, Inc.