A structural approach to finding the point correspondences between two frames

A recursive-descent tree-traversal algorithm is presented to find the point correspondences between two frames. Given two sets of noisy 3-D feature points on multiple rigid objects at two time-sequential views, the points at the first frame are constructed as a graph, and another graph is derived from those feature points at the second frame so that maximal matching points and minimum matching error are obtained. The correspondence of the vertices can then be found. The algorithm can also be used when the number of points at two frames are different. The computation time of the algorithm is large when the number of feature points is large. A date-set-splitting strategy for such cases is presented which can significantly reduce the computation time. Another algorithm is presented in which motion parameters are estimated from matched subgraphs and are used to guide the matching for the rest nodes. Computer simulations are performed to show the efficiency and accuracy of the algorithms