Vehicle license character feature extracting and classifying method based on projection symmetry

Abstract

The invention provides a vehicle license character feature extracting and classifying method using projection symmetry as the precondition for judgment. The method comprises the following steps: firstly extracting character feature to 26 letters and 10 numbers which may appear in vehicle license characters by using projection symmetry as precondition to divide into four classes, namely vertical projection class, horizontal projection class, central point projection class and dissymmetric property class and realize the coarse classifications of vehicle license characters; and fining, performing normalization transformation, then extracting features of points and rings and completing the fine classification of vehicle license characters. The invention combines the projection symmetry with the feature extraction method of points and rings to set a vehicle license character classifier, thus laying the foundation of realizing the identification of vehicle license characters finally. The method has better identification effect on confusable characters, such as '0' and 'D', '8' and 'B', '7' and 'T' and the like, thus increasing the identification speed and accuracy of vehicle license characters.

Description

technical field [0001] The invention relates to an automatic recognition method for a character image of a motor vehicle license plate, belonging to the technical fields of pattern recognition and computer image processing. Background technique [0002] With the development of traffic modernization, the automatic recognition technology of motor vehicle license plate has been paid more and more attention by people. The automatic license plate recognition technology is an important part of the intelligent transportation system, and the quality of the character feature extraction of the license plate will directly affect the setting of the classifier, which plays an extremely critical role in improving the speed and recognition rate of the license plate. License plate recognition technology mainly involves image processing, pattern recognition and other technologies. The feature extraction and classification of license plate characters will directly affect the performance of t...

AI Technical Summary

Problems solved by technology

[0004] In character recognition, a feature is an attribute or measure of a certain type of pattern. For different recognition objects, different feature extraction methods must be considered. It is difficult to have a unified method and theory.

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