License plate positioning method and system based on cascading morphological transformation

Abstract

The invention relates to a license plate positioning method and a license plate positioning system based on cascading morphological transformation. The method comprises: performing downsampling and grey processing on an original image to obtain a gray image; performing cascading morphological transformation and binaryzation on the gray image, primarily screening a communicating area to obtain a plurality of candidate areas; computing the similarity between the color histogram information of each candidate area and the color histogram information of a standard license plate, and judging a license area according to the similarity; mapping the license plate areas into the original image through the inverse operation of downsampling, and thereby obtaining the corresponding original license plate area. According to the license plate positioning method and system based on cascading morphological transformation, gray processing, cascading morphological transformation and binaryzation are performed on the image to improve robustness in the positioning of candidate areas of the license plate and positioning speed of the license plate, meanwhile interference of strong light is suppressed, the contrast ratio of characters in the license plate area is increased, and screening accuracy of the license plate area is improved; the license plate positioning method and system based on cascading morphological transformation are applicable to environments with different light conditions and complex scenes, and can be used for simultaneously positioning the plurality of license plates.

Description

technical field [0001] The invention relates to the technical field of image processing, in particular to a license plate location method and system based on cascade morphological transformation. Background technique [0002] Intelligent transportation is widely used in the management of vehicles in smart cities. License plate recognition is one of the core technologies, which is the application of computer image processing technology and pattern recognition technology in the field of intelligent transportation. License plate recognition technology is widely used in highway bayonet capture systems, intelligent parking systems and community vehicle management systems. The license plate recognition process is basically divided into three steps: license plate positioning, character cutting and character recognition. Technology is a crucial step in the license plate recognition technology. As the first step in the entire license plate recognition process, the successful positio...

AI Technical Summary

Problems solved by technology

The matching method of prior knowledge is more easily affected by light, pollution, and the environment, and the accuracy is lower

[0004] Most of the existing license plate location methods are only suitable for scenes with little background changes, such as toll booths and security cards. However, for various natural environment scenes in complex panoramas (for example, street view panoramas), the backgrounds are ever-changing. Especially for those panoramas containing a large number of trees and striped textured items, the existing license plate positioning methods are difficult to apply

Moreover, the existing license plate positioning methods have high requirements for the quality of the collected pictures, and are sensitive to light. If the license plate is too bright or too dark, the existing license plate positioning methods cannot handle it well, and its anti-interference Poor (that is, its robust--robustness is not high)

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