<title>Hierarchical Contour Coding And Generalization Of Shape</title>

Abstract

The complete information about contour structures of a gray level image can be encoded by a hierarchical procedure. Continuity of lines and edges is explicitly checked and extended continuous structures are encoded at high levels of a hierarchical contour code (HCC), while less extended details are available at lower levels. Though contour information is processed in seperate spatial frequency channels, correspondence is arranged by the special structure of the code. By this approach, a pattern recognition system may be split into a general purpose front end, encoding the complete contour information of a gray level image, and into a recognition part with top down access to this code, using only as much information as necessary for an unambiguous identification of the scene. This structure is very promising for robot vision applications, as the general purpose coding system can be implemented in real time hardware and as the recognition part is relieved of processing the complete gray level image.