Vehicle license plate recognition method

A license plate recognition and license plate technology, applied in the field of recognition graphics, can solve the problems of a single application scenario, difficult to apply multiple license plate recognition, and the recognition rate is easily affected by strong light, haze and weak light environments.

Inactive Publication Date: 2016-03-02
HEBEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to provide a license plate recognition method, determine the vehicle area according to the prior knowledge of the color and texture features of the license plate itself, segment the vehicle area, and then use the relationship between the center pixel and its neighboring pixels to obtain the vehicle area. Regional saliency factor map, use the Adaboost classifier based on extended Haar-like features to obtain candidate license plates, verify the candidate license plates, complete the license plate location, a

Method used

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  • Vehicle license plate recognition method
  • Vehicle license plate recognition method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0111] The concrete steps of a kind of license plate recognition method of the present embodiment are as follows:

[0112] The first step, image preprocessing:

[0113] Read in the original color road traffic images collected by the camera, and establish a training data set for the Adaboost classifier, including 4,000 manually intercepted color images of license plate positive samples in different scenarios, and 20,000 intercepted images including roads, trees, and car bodies. Color images of scene negative samples of different sizes, preprocess all sample color images in the data set, normalize the size of license plate positive sample color images to 64×20 pixels, and do not normalize the scene negative sample color images , but ensure that the size of the color image of the negative sample of the scene is larger than the color image of the positive sample of the license plate, so that the training image of the size of the positive sample can be intercepted from the negative...

Embodiment 2

[0183] Except for the second step (3) in the vehicle area segmentation: first perform vertical projection to obtain 2 vertical projection areas, perform horizontal projection in the projected area, record the projection edge, and finally obtain 2 vehicle areas, other implementations are the same example 1. Example 3

Embodiment 3

[0184] Except for the second step (3) in the vehicle area segmentation: first perform vertical projection to obtain 3 vertical projection areas, perform horizontal projection in the projected area, record the projection edge, and finally obtain 3 vehicle areas, other implementations are the same example 1.

[0185] The above embodiment is a license plate recognition method, and the units of the width and height are pixels.

[0186] The foregoing embodiment is a license plate recognition method, which is only applicable to blue license plates in China (mainland).

[0187] A kind of license plate recognition method of above-mentioned embodiment all utilizes VS2005 development platform and OpenCV2.0 storehouse to realize, and processor adopts AMDA8-7100, 4G internal memory, and experimental sample storehouse can be divided into multiple scenes, comprises clear daytime, clear nighttime, weak light , rainy days, foggy weather, strong light, vehicle images from road checkpoints and...

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Abstract

The invention provides a vehicle license plate recognition method, and relates to a method for image recognition. The method comprises the following steps of preprocessing an image; partitioning a vehicle region according to color and texture characteristics; extracting a remarkable factor graph of a vehicle region diagram; extracting candidate vehicle license plates by an Adaboost classifier based on expanded Harr-like characteristic; determining the position of a real vehicle license plate from the candidate vehicle license plates; partitioning the marked vehicle license plate from the corresponding vehicle region original diagram; carrying out character segmentation according to structural characteristic; and carrying out character recognition based on the improved template matching method. With the method provided by the invention, the defects that the application scene of the traditional vehicle license plate recognition method is relatively single, some traditional vehicle license plate recognition methods are only suitably used for single vehicle license plate recognition of the single scene and difficultly used for multiple-vehicle license plate recognition of multiple scenes, and the recognition rate is easily affected by strong light, haze and weak light environments are overcome.

Description

technical field [0001] The technical solution of the present invention relates to a method for recognizing graphics, specifically a method for recognizing a license plate. Background technique [0002] Intelligent Transportation System (Intelligent Transportation System, hereinafter referred to as ITS) helps to solve more and more vehicle management problems faced by traffic, and license plate recognition is an important part of the vehicle detection system in ITS, which can be applied to highway toll management systems, high-speed Highway speeding automatic supervision system, electronic police at urban traffic intersections, parking lot fee management system and other fields. [0003] The license plate location technology is the main link of the license plate recognition system. The more common method in the prior art is to use the color and texture information of the license plate combined with the morphological processing method to obtain the license plate area, but it i...

Claims

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Application Information

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IPC IPC(8): G06K9/34G06K9/46G06K9/62
CPCG06V30/153G06V10/56G06F18/2413G06F18/214
Inventor 于洋阎刚于明师硕刘依张亚娟耿美晓
Owner HEBEI UNIV OF TECH
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