Image-brightness-characteristic-based pan/tilt/zoom (PTZ) video visibility detection method

Abstract

The invention discloses an image-brightness-characteristic-based pan / tilt / zoom (PTZ) video visibility detection method, which comprises the following steps of: acquiring a road condition video image by using a PTZ video camera, extracting a region of interest (ROI) of the road surface, and acquiring high consistency of the selected pixels; obtaining an accurate road surface region by utilizing a Nagao-filtering-based regional growth algorithm, and ensuring consistent illumination of the selected pixels in a world coordinate; in the road surface region, extracting a contrast curve reflecting the road surface brightness change, searching brightness curve characteristic points, and calculating the farthest pixel which can be identified by human eyes in the image through an extinction coefficient; and combining the camera to calibrate and convert the maximum visual range, and determining a visibility value. In the method, artificial markers are not needed to be set, the existing PTZ camera is fully utilized to shoot road condition and acquire images, can monitor the road condition in real time, and is low in monitoring cost; moreover, the requirement on large-area road condition monitoring is met, the monitoring is stable and is not interfered by external environment, and the visibility monitoring method is easy to implement, high in accuracy and good in effect.

Description

technical field [0001] The invention belongs to the technical field of image processing, and relates to camera calibration technology, self-adaptive Nagao filter technology, noise suppression technology, visibility solution technology and the like. Contrast curve, find the feature points of the brightness curve, calculate the furthest pixel in the image that can be distinguished by the human eye through the extinction coefficient; combine the camera calibration to convert the maximum visibility distance, and determine the visibility value, specifically a PTZ video visibility detection based on image brightness characteristics method. Background technique [0002] Expressway is an emerging industry related to the national economy and people's livelihood. In 2010, my country's total mileage is planned to exceed 80,000 kilometers. Jiangsu is an economically developed area in my country and a leader in ITS (Intelligent Transportation System). At present, there are 3,558 kilome...

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Problems solved by technology

[0020] The problem to be solved by the present invention is: there are deficiencies in the monitoring of visibility in the prior art, such as relatively large detection limitations, inability to meet the requirements of large-area road condition monitoring, insufficient real-time monitoring, high monitoring costs, and easily affected monitoring accuracy, etc.; Need a simple and easy to implement, high precision and good visibility monitoring method

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