ANAMORPHIC MULTIPLE MATCHED-FILTER FOR CHARACTER-RECOGNITION, PERFORMANCE WITH SIGNALS OF EQUAL SIZE

The construction and performance of an anamorphic multiple matched filter for character recognition is presented, in the usual situation of characters of equal input size and having the same size in the target. So a simple anamorphic correlator can be employed to obtain the recognition of a given character. In order to avoid false alarms the characters in the target are rotated by different angles depending on the angular tolerance of the correlator, which is rotationally variant and smaller than in symmetrical systems within a certain angular region. Thus the number of signals to which the filter can be matched can be greater than with spherical optics correlators. © 1990 Taylor & Francis Ltd.