On the application of geometrical form description techniques to automatic key-sections recognition

Automatic key-section recognition is approached by a two-step procedure. The first step is a screening based on arc/straight-segment classification, which associates to each key section a morphological pattern. The second step measures the string distances by means of nonlinear elastic matching among the key-sections possessing the same morphological description. Arc/straight-segment classification, a typical geometrical form description problem, is studied by two techniques, one based on Euclidean geometry notions and the other based on discrete geometry. The results achieved by the second technique appear superior. The performance of the recognition procedure on key-section databases of practical significance are very satisfactory