License plate localization and identification method based on high-definition image

Abstract

The invention discloses a license plate localization and identification method based on a high-definition image, comprising the following steps of: (1) carrying out one-time downsampling on the original color images, graying the downsampled images and carrying out vertical edge detection and binaryzation on the images, and carrying out license plate rough localization by utilizing vertical edge information to obtain all candidate license plate areas; (2) mapping all the candidate license plate areas into the original images and sending to a trained cascade Adaboost grader so as to remove non-license plate areas; (3) carrying tilt correction on the license plate areas obtained in the step (2); (4) carrying out character segmentation on the license plate areas obtained in the step (3); and (5) identifying segmented characters. The invention can rapidly and effectively extract a plurality of license plates in different sizes from a complicated scene and can effectively improve the character identification accuracy. The license plate localization and identification method has wide application prospect in the aspects of intelligent transportation, parking lot management, residential quarter management, and the like.

Description

technical field [0001] The invention relates to a license plate positioning and recognition method, in particular to a high-definition image-based license plate positioning and recognition method. Background technique [0002] With the development of the economy, the number of cars has increased sharply, and the management requirements for traffic and public security are also increasing. Using high-definition camera imaging technology, it can not only capture the license plate clearly, but also provide high-quality images of the faces of the drivers and passengers in the front row. And it can record the whole picture of the vehicle and the information on the vehicle, so as to meet the needs of multiple business departments such as criminal investigation, public security, and traffic police. In addition, with a camera with 2 million or higher pixels, one camera can capture 2-3 lanes, and the system construction efficiency is also significantly improved. Therefore, high-defin...

AI Technical Summary

Problems solved by technology

[0003] However, the existing license plate recognition technology based on standard-definition images is difficult to directly apply to high-definition images, because high-definition images have a large viewing range, a large amount of data to be processed, and more complex backgrounds. Several license plates, the size of the license plate in different lanes is not the same, the existing license plate recognition system based on standard definition images generally has a simple background and only recognizes a single license plate in a single lane, and the recognition of similar characters and degraded characters has always affected the accuracy of license plate character recognition Therefore, how to quickly and effectively extract multiple license plates of different sizes from complex scenes and improve the recognition rate of similar characters and degraded characters is an important problem to be solved in the existing license plate recognition technology

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