License plate detection method and system

Abstract

The embodiment of the invention provides a license plate detection method and system. The method includes the steps of obtaining a license plate image, carrying out gray-scale treatment on the license plate image to obtain a gray-scale image, carrying out discrete cosine transformation, sign conversion, square operation, inverse discrete cosine transform and binarization processing sequentially on the gray-scale image to obtain an edge obvious feature graph, searching for the area with the edge density larger than a preset threshold in the edge obvious feature graph to obtain an uncertain license plate area, and detecting the uncertain license plate area by means of a license plate classifier to obtain a license plate area. The method and system are more suitable for hardware implementation, and an algorithm can be transplanted into an embedded system more easily.

Description

technical field [0001] The invention relates to the technical field of image processing, in particular to a license plate detection method and system. Background technique [0002] At present, license plate recognition equipment has been widely used in parking lots, urban roads, expressways and other areas to automatically capture and recognize vehicle license plates. License plate recognition technology can be divided into license plate detection, license plate detection, license plate segmentation and recognition, and license plate voting. One step, wherein, license plate detection refers to detecting the license plate area in the license plate image containing the license plate area, because the license plate area in the license plate image is often only a small part of the license plate image, therefore, license plate detection is often a license plate The most time-consuming step in recognition technology. With the popularity of high-definition cameras, the use of high...

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Problems solved by technology

[0003] In view of this, the embodiment of the present invention provides a license plate detection method and system to solve the problem of directly using a license plate classifier to detect the license plate area on the acquired license plate image in the prior art. In the process of obtaining the license plate area, the amount of calculation is huge. If it is applied in an embedded device, its speed will not meet the requirements, and it is not applicable to the problem of hardware device implementation

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