Extraction of shape features for syntactic recognition of mechanical parts

A language for describing the shape of those mechanical parts modeled by the rotational or translational sweeping (based on boundary representation) is presented. Each boundary is represented by a contour composed of primitives from the specified set. A work (in the mentioned language) is the description of a given contour and constitutes an input to the detector (transducer). Its output is a compact representation of the contour (i.e. mechanical part). This output is a sequence of descriptors, each consisting of two characters, and their meaning allows regions (features) to be extracted and exactly characterized. These regions are arranged to form global features such as grooves, flanks, complex grooves, and cascades. The global features, which have the important technology meaning, are extracted by means of very simple algorithms. These algorithms may be applied for extracting features of an arbitrary plane shape described in the language developed.