Detection method and device for tripwire crossing of object and video monitoring system

Abstract

The application relates to a detection method and device for tripwire crossing of an object and a video monitoring system. The method includes a range-point determination step: according to a received tripwire which is drawn on a video image by an operator, determining an effective range used for detecting tripwire crossing by a moving object and selecting two points, which are at the two sides of the tripwire respectively, in the effective range as a first judgment point and a second judgment point; and an tripwire crossing judging step: detecting the position of the moving object and according to changes of distances between the position of the moving object and the first judgment point and the second judgment point respectively, determining that the moving object crosses the tripwire. Through determination of the effective range, it is prevented that when the object passes by outside the tripwire, the behavior is also regarded as a boundary-crossing behavior and at the same time, in judging whether the object is boundary-crossing, not only is a front and rear coordinate position relation of the moving object judged, but the two points at the two sides of the tripwire are also selected in the effective range as a judgment basis to determine whether the moving object is boundary-crossing so that accuracy in judging whether the tripwire is crossed is improved.

Description

technical field

[0001] The present application relates to the technical field of video surveillance, in particular to a method and device for detecting a target passing a trip wire in a video image, and a video surveillance system. Background technique

[0002] Video surveillance is widely used. Through intelligent analysis of video, it can be judged whether there is an active target crossing the boundary or invading the area of ​​interest. At present, commonly used analysis techniques use methods such as setting trip wires or areas to make judgments. Tripwires are generally used as perimeters, and if a target crosses the tripwire from outside the perimeter into the inside of the perimeter, that is, from one side of the tripwire to the other side, an alarm is issued. The current method of judging whether the target has passed the trip wire is usually, such as figure 1 As shown, set a tripwire in the image, there are two coordinates x and y in the image plane, x is the hori...

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