Abstract: In the optical measuring of planar parts, the registration of 2D point contour and planar
vector contour is the key algorithm, the speed and precision of registration has a major impact on the
speed and precision of measure result. In order to solve the problem of registration of 2D point cloud, a
coarse registration algorithm based on shape feature function and a 2D iterated closest point (ICP) fine
registration algorithm are researched. Through the angle-distance graph, geometry information of point
contour and planar vector contour is translated to continuous function that is independent of coordinate
system. The objective function of registration is calculated on account of nearest distance algorithm on
planar point and curve, and analytic method of solving the objective function directly is given, which is
different from traditional ICP algorithm. The efficiency of algorithm is improved significantly.
Examples are exhibited to analysis the efficiency and reliability of the algorithm.

Key words: planar vector graphics, 2D point cloud, coarse registration, fine registration, iterated closest
point algorithm