On the optimal detection of curves in noisy pictures

A technique for recognizing systems of lines is presented. In this technique the heuristic of the problem is not embedded in the recognition algorithm but is expressed in a figure of merit. A multistage decision process is then able to recognize in the input picture the optimal system of lines according to the given figure of merit. Due to the global approach, greater flexibility and adequacy in the particular problem is achieved. The relation between the structure of the figure of merit and the complexity of the optimization process is then discussed. The method described is suitable for parallel processing because the operations relative to each state can be computed in parallel, and the number of stages is equal to the length N of the curves (or to log2 (N) if the approximate method is used).