Method for locating license plate under a complicated background

Abstract

The invention discloses a method for locating a vehicle license plate in complex background. The method comprises the following steps: (1). Differentiating a gray scale mean of a fixed-size region and extracting a vehicle body image from a video; (2). preprocessing the vehicle body image such as gradation, gradient information enhancing, binarization and the like; (3). performing mathematical morphology operation on the processed vehicle body image, and performing primary screening by combining structural features of the vehicle license plate to obtain a plurality of candidate vehicle license plate regions; (4). converting the obtained candidate vehicle license plate regions into an HSV color spatial image; (5). adopting a BP neural network to perform color identification on the HSV color spatial candidate vehicle license plate image, and performing color edge detection by computing the mean color distance between two adjacent regions of a certain pixel; (6). judging edge color pair of an edge point, and eliminating the false vehicle license plate edge; and (7). performing final vehicle license plate location by the texture feature of the vehicle license plate. The method is suitable for complex background, and has higher location accuracy rate and higher robustness.

Description

technical field [0001] The invention relates to a license plate positioning technology, in particular to a license plate positioning method under a complicated background. Background technique [0002] At present, many cities in my country have established traffic control centers, and video surveillance has become the main means of traffic management, which also means that License Plate Recognition (LPR) technology will play an increasingly important role. Automatic license plate recognition system can be widely used in the following occasions: highway, bridge, tunnel and other toll management systems; urban traffic vehicle management, electronic police, customs border traffic monitoring; intelligent community, intelligent parking lot management; license plate verification, traffic statistics, etc. Using this technology in the above occasions can realize real-time and efficient monitoring of vehicle dynamics, making it possible to realize functions such as non-stop charging,...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the disadvantages of the existing license plate positioning methods that cannot adapt to complex backgrounds, poor reliability, and more color loss, the present invention provides a license plate positioning method that adapts to complex backgrounds, extracts the car body from the video, and removes the complex background to the greatest extent. Interference, and the comprehensive application of color images and grayscale images for license plate location, higher positioning accuracy and higher robustness

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