Bayonet vehicle retrieval method based on camera perspective transformation

Abstract

The invention relates to a bayonet vehicle retrieval method based on camera perspective transformation. The method includes the steps that a bayonet vehicle image is subjected to feature point positioning firstly, and the four corners of a front windshield, the four corners of a front engine hood, headlamps, a vehicle logo, a license plate, front tires and the like are mainly included; then, priori knowledge of feature points of the vehicle is utilized, for example, the four corners of the front windshield are located on the same plane, the four corners of the front engine hood are located on the same plane, and a reference plane for perspective transformation and a perspective transformation virtual camera model are established; finally, according to the established camera model, external parameters of a camera are adjusted, the image is subjected to perspective transformation to form a certain fixed visual angle, and for example, the CCD plane of the camera is parallel to the plane where the front windshield is located. By means of the method, vehicle visual angle errors brought by the bayonet difference can be reduced, and retrieval performance is greatly improved.

Description

technical field [0001] The invention relates to a bayonet vehicle retrieval method based on camera perspective transformation. Background technique [0002] At present, most of the vehicle retrieval technologies with practical value are applied to road bayonets. The main reason is that the installation of bayonet cameras is standardized, thus ensuring that the captured vehicles are all head images, and the angle of view is within a certain range. . [0003] But even so, due to factors such as camera installation errors, lane differences, and vehicle driving directions, the vehicle images between different bayonets still have large differences in viewing angles, which leads to subsequent vehicle retrievals based on a certain viewing angle. Error, which is also the factor that has the greatest impact on performance in vehicle retrieval techniques. [0004] For this problem, there are few direct solutions in the existing technology, mostly in the vehicle feature extraction, t...

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Problems solved by technology

[0005] There are only a few patents, such as "201510081237.1", which deal with the viewing angle problem in a targeted manner, but this patent uses the simplest and violent multi-model method. In actual use, the same car is unlikely to have the opportunity to build a multi-view model. On the other hand, multiple models will also greatly increase the amount of data storage. For a small city with tens of millions of bayonet pictures per day, if multiple models are used to store feature data, the hardware cost will be greatly increased.

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