Traffic video visibility detecting method based on road surface brightness and least square approach

Abstract

The invention discloses a traffic video visibility detecting method based on the road surface brightness and the least square approach, and belongs to the technical fields of video image processing and visibility detecting. The detecting method comprises the following steps: 1) acquiring road traffic video images; 2) calibrating the acquired images by a Pan/Tilt/Zoom camera to extract a road surface region of interest (ROI); 3) extracting a road surface region formed by pixel points with the same brightness in the ROI and calculating the value of the road surface brightness; 4) by virtue of combination with the Koschmieder theory and the least square principle, building a squared brightness difference objective function to obtain the optimal solution of an extinction coefficient k; 5) transforming the optimal solution of the extinction coefficient k into image visibility distance Vmet; 6) drawing a curve of visibility changing along with time, observing the visibility condition and performing prejudgment. Proven by experiments, the method is compatible with an existing common traffic condition monitoring system, high in calculation accuracy, high in speed, excellent in robustness to noise, and wide in application prospect.

Description

technical field [0001] The invention relates to the technical fields of video image processing and visibility detection, and more specifically, to a traffic video visibility detection method based on road surface brightness and least square method. Background technique [0002] Severe weather such as fog and haze is a factor that seriously affects driving safety on expressways. Traffic congestion and even vicious accidents caused by low visibility occur frequently every year. According to relevant research reports, traffic accidents occurring in special weather account for about 24% of the total traffic accidents. Therefore, timely, accurate and effective monitoring and early warning of road visibility in severe weather is of great significance. Traditional visibility monitoring instruments are expensive, often costing hundreds of thousands, and cannot be deployed densely. At the same time, visibility monitoring instruments use the dynamic scattering mechanism of the atmosp...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the problems of high price of traditional visibility meter and low precision, low stability and poor timeliness of the traditional detection method in road visibility detection in the prior art, and provides a camera-based calibration , brightness calculation and objective function optimization traffic video visibility detection method, the present invention is mainly used in the highway monitoring system that adopts PTZ camera, at first the video image that PTZ camera collects is processed, extracts the road surface area that satisfies the condition, guarantees road surface Consistency of height and brightness, excluding surrounding noise interference, solves the problem of poor stability of traditional methods, and only calculates the road surface area that meets the conditions in units of image lines when calculating visibility values, rather than all pixels of the entire image Calculate one by one, improve the calculation speed, more suitable for real-time monitoring

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