“…where d ij is the spatial distance from one point to its neighbor point, k j is the curvature of the neighbor point, f j is the neighborhood weighted angle-invariant feature, m is the number of neighbor points. It should be noticed that x, y, z, f, k, u, and v constitute our feature descriptor, in which x, y, z are the coordinates of point, f is the neighborhood weighted angle-invariant feature, k is the curvature, u and v are from formula (6). We use the data obtained by calculating the normal vectors of points to build a feature that fully expresses the neighborhood information, thus the speed and accuracy of feature calculation and correspondence building are improved.…”