There are the characters of large data

strong effectiveness and complex environment in a single-frame image of illegal encroaching vehicles

the detection of illegal encroaching vehicles requires amount of experimental work and labor. In the process of positioning license plates

people cannot avoid some interference such as experience

fatigue

which results in missing and misplacing license plates. The computer-assisted location algorithm of license plates is proposed from the perspective of visual perception

and used the method of multiple scales in this paper. Simulating the visual perception principle

the computer successively focused to the license plate area according to vehicle characteristics

texture features

and color characteristics scale. We put forward a complete license plate positioning process for the single-frame image and propose an accurate location algorithm for license plate area based on boundary pair. The experiments on real traffic images show that the proposed algorithm has a higher accuracy rate when the image is acquired from the head or rear of vehicles

and is consistent with the process of human visual perception

and can detect multiple license plates on the single image at the same time. But further study need to be carried in the situation of too dark environment

too bright light or color distortion.