Combining texture and shape for automatic crude patch registration

Building complete three-dimensional models often requires the registration and integration of multiple partial reconstructions. Registration is usually performed using a coarse-to-fine approach. We present a novel method for the crude registration of many partial three-dimensional reconstructions (patches). Our method combines the 3D measurements with the texture. Registration with methods that use only geometry will fail if the shape is too simple or symmetric. In such cases one has to use texture to resolve the ambiguities. But even then, knowledge of the shape greatly simplifies the task. The strategy we use is to intersect the surface with small spheres centered at feature points. The intersection line between such a sampling sphere and the surface defines an invariant region in the texture image. The surface texture inside these regions is used for matching regions between different patches.