Method and system for retrieving license plate

Abstract

The invention discloses a method for retrieving a license plate. The method comprises a step of obtaining license plate precise positioning coordinates according to an inputted license plate image, a step of intercepting a predetermined license plate area image in the license plate image by using the license plate precise positioning coordinates, a step of taking the predetermined license plate area image as the input of a convolutional neural network model, obtaining a full connection layer characteristic, and forming a characteristic vector according to a predetermined order, a step of using a dimension reduction model to carry out dimension reduction of the characteristic vector into a predetermined dimension characteristic vector, and a step of carrying out cosine distance comparison of the predetermined dimension characteristic vector of a corresponding vehicle and a predetermined dimension characteristic vector of a specified vehicle, and determining license plate information. According to the method, in the condition of license plate matching failure, the license plate information corresponding to the vehicle can be accurately retrieved in a specified range, the license plate retrieval is realized, and the number of security personnel arranged at each gate of a parking lot is reduced. The invention also discloses a system for retrieving a license plate with the above advantages.

Description

technical field [0001] The invention relates to the technical field of image processing, in particular to a license plate retrieval method and system. Background technique [0002] At present, the license plate recognition rate is already very high, which can basically reach more than 99%, but the 1% recognition and matching error is often the most troublesome problem for customers in the actual use of parking lot import and export. In the era of low license plate recognition rate, there is a 100% accuracy rate for one car and one card, and users do not need to worry about the mismatch between the entering vehicle and the exiting vehicle. When the license plate recognition rate becomes higher, merchants see that automatic license plate recognition solves the problem of slow vehicle entry and card collection. Although the problem of one vehicle with one card has been eliminated through automatic license plate recognition, a new problem is that when the vehicles entering the ...

AI Technical Summary

Problems solved by technology

The advantage of method 1 is that it is convenient and quick, and it can be realized without adding redundant modules, but the disadvantage is that it still cannot solve the problem that the recognition results are misplaced or the recognition results cannot match at all

The advantage of method 2 is that it provides a more reliable solution different from method 1, but the disadvantage is that there are many types of models, training is difficult and time-consuming

Therefore, how to solve the problem that 1% of the recognition cannot be matched by using pure license plate recognition is a technical problem that those skilled in the art need to solve.

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