Nonrigid Point Set Registration by Preserving Local Connectivity

This paper is concerned with the nonrigid point set registration problem and a probability-based registration algorithm with local connectivity preservation is proposed. A unified formulation for point set registration problem is introduced and the derived energy function is composed of three parts, distance measurement item, transformation constraint item, and correspondence constraint item. In order to preserve the local structure of point set, the definitions of k-connected neighbors and connectivity matrix are given and the local connectivity constraint is constructed as a weighted least square error item. The point set registration problem is formulated in the expectation-maximization algorithm scheme and the optimal spatial transformation and correspondence matrix are estimated simultaneously. The effectiveness of the proposed method is verified by applying the method to synthetic point sets and real scenarios of hand shapes and surface-mount technology components.