On the application of formal language and automata theory to pattern recognition

Abstract This paper studies M-way automata as a method of defining patterns in a multidimensional discrete space. It is shown that the membership question is recursively solvable for large classes of automata while the emptiness question is r, unsolvable even for the class of M-way finite automata. Efficient recognition algorithms are given for the pattern sets defined by M-way pushdown automata and certain error operators designed to make a set of patterns insensitive to noise are also presented and studied.