FAST FULLY PARALLEL THINNING ALGORITHMS

Three new fast fully parallel 2-D thinning algorithms using reduction operators with 11-pixel supports are presented and evaluated. These are compared to earlier fully parallel thinning algorithms in tests on artificial and natural images; the new algorithms produce either superior parallel computation time (number of parallel iterations) or thinner medial curve results with comparable parallel computation time. Further, estimates of the best possible parallel computation time are developed which are applied to the specific test sets used. The parallel computation times of the new algorithms and one earlier algorithm are shown to approach closely or surpass these estimates and are in this sense near optimally fast. © 1992.