Multi-method integrated license plate image positioning method

Abstract

The invention relates to a license plate positioning method integrating multiple methods and adopting the steps as follows: pretreatment is carried out to collected license plate images; a self-adapting matching template is obtained by a self-adapting template matching method which is based on data stream correcting and coarse positioning of the license plate images is realized by a template matching algorithm; edge detection is conducted to the license plate images after the coarse positioning by utilizing morphology gradient method so as to highlight the character areas of the license plates; aiming at distorted license plate images, a method for detecting the main direction of the characters in the license plate images is adopted for correcting; a projection method is adopted for precise positioning so as to achieve precise positioning of the character areas of the license plates, thus realizing the precise positioning of the license plate images. The license plate image positioning method designed by the invention has low requirements on the adaptability of environment and high arithmetic speed, can fulfill the requirements of precision and real-time performance for license plate identification and provides high-quality license plate images for subsequent partitioning and identification of license plate characters.

Description

technical field [0001] The invention relates to an automatic positioning method of a license plate (motor vehicle number plate) image fused by multiple methods, belongs to the technical field of computer image processing, pattern recognition and intelligent transport system (Intelligent Transport System, ITS) control, and is an important part of the intelligent transport system. An important link in automatic license plate recognition technology. Background technique [0002] The license plate recognition technology based on computer image processing, pattern recognition and other technologies has aroused great interest of researchers, and the license plate recognition system (License Plate Recognition System, LPRS) composed of various license plate recognition technologies has also emerged at the historic moment. [0003] The license plate recognition system is a highly intelligent integrated system based on computer image processing, pattern recognition and other technolog...

AI Technical Summary

Problems solved by technology

[0013] ② The suspension of the license plate is not standardized, and some license plates are tilted or twisted;

[0014] ③Due to natural or man-made reasons, the color of the license plate cannot be kept as a few fixed colors, and the color of the same license plate may also have a large change and other factors;

[0015] ④Due to inappropriate shooting positions, some license plate edges are blocked

[0016] Due to the complexity of the license plate image background, the diversity of license plate features and the influence of various factors, there is still no completely effective solution so far, and the satisfactory results obtained by many methods are at the cost of time-consuming or reduced system performance.

The license plate recognition system has very high requirements for recognition accuracy and real-time performance, which limits the practical application.

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