Character recognition method

摘要

The present invention is intended to provide a character recognition method which can accurately presume each character area in an input image of a license plate even in case if the input image lacks information (for example, a part of the number plate is not contained or a part of a serial number is hidden by an obstruction) or contains noise signals caused by both side frame of the license plate and/or an indicating lamp. The present invention comprises: Character-circumscribing-rectangle extracting means (105) extracts information on rectangles circumscribing respective characters from an input binary quantized image. Plate-frame presuming means (106) sets a plurality of temporary plate-frames (401) prepared according to known character areas (a serial number area Nk, a use-code area Y, an administration branch office-name /classification-number area R) of license plates, compares the character-circumscribing rectangle information to the character areas and selects, as a correct plate-frame, a plate-frame which is least contradictory in relative positions of character areas to the rectangle information. Characters in respective character areas on the correct plate frame (400) are recognized.