Matching Tensors for Automatic Correspondence and Registration

Complete 3-D modeling of a free-form object requires acquisition from multiple view-points. These views are then required to be registered in a common coordinate system by establishing correspondence between them in their regions of overlap. In this paper, we present an automatic correspondence technique for pair-wise registration of different views of a free-form object. The technique is based upon a novel robust representation scheme reported in this paper. Our representation scheme defines local 3-D grids over the object’s surface and represents the surface inside each grid by a fourth order tensor. Multiple tensors are built for the views which are then matched, using a correlation and verification technique to establish correspondence between a model and a scene tensor. This correspondence is then used to derive a rigid transformation that aligns the two views. The transformation is verified and refined using a variant of ICP. Our correspondence technique is fully automatic and does not assume any knowledge of the viewpoints or regions of overlap of the data sets. Our results show that our technique is accurate, robust, efficient and independent of the resolution of the views.