A sequential tracking extraction of shape features and its constructive description

Based on sequential tracking, a machine composed of three sequentially connected automata is proposed for recognizing a plane shape given by binary pattern. The first automaton detects 10 kinds of quasi-local features which constitute a complete set of features in two consecutive lines. The second automaton integrates these features and segments a contour into letter L shaped segments which are considered as primitives for description of a shape. These L-type segments are arranged to form the structure. The third automaton extracts global features such as connectivity, hole, and concavity, where attribution of a hole to a blob is somewhat generally treated and some degree of closure of a concavity is described. Thus the systematic feature extraction of a plane shape and the simple and essential description of that shape is given.