Real time processing of video frames

摘要

A method and system for real time processing of a sequence of video frames. A current frame in the sequence and at least one frame in the sequence occurring prior to the current frame is analyzed. Each frame includes a two-dimensional array of pixels. The sequence of video frames is received in synchronization with a recording of the video frames in real time. The analyzing includes performing a background subtraction on the at least one frame, which determines a background image and a static region mask associated with a static region consisting of a contiguous distribution of pixels in the current frame. The static region mask identifies each pixel in the static region upon the static region mask being superimposed on the current frame. A determination is made that a persistence requirement, both a non-persistence duration requirement and a persistence duration requirement, or a combination thereof have been satisfied.

主权项

1. A method for real time processing of a sequence of video frames, said method comprising:
analyzing, by a processor of a computer system, a current frame in the sequence and at least one frame in the sequence occurring prior to the current frame, each frame comprising a two-dimensional array of pixels and a frame-dependent color intensity at each pixel, said array of pixels in each frame being a totality of pixels in each frame in the sequence of video frames, said analyzing comprising performing a background subtraction on the at least one frame, said performing the background subtraction determining a background image and also determining a static region mask associated with a static region consisting of a contiguous distribution of pixels in the current frame, said static region mask identifying each pixel in the static region upon the static region mask being superimposed on the current frame, said background image comprising the array of pixels and a background model of the at least one frame and not comprising any moving object; after said analyzing, said processor determining that at least one requirement has been satisfied, said at least one requirement selected from the group consisting of a persistence requirement, both a non-persistence duration requirement and a persistence duration requirement, and a combination thereof; responsive to said determining that the at least one requirement has been satisfied, said processor triggering the alert, wherein the persistence requirement is that the static region in each frame of a plurality of frames is persistent relative to the reference frame, said plurality of frames occurring during a time interval immediately following a time of occurrence of the reference frame. wherein the non-persistence duration requirement is that for each frame of one or more frames in at least one time period during the time interval, the static region is non-persistent relative to the static region in the reference frame and that a cumulative time duration (TNP) encompassed by the one or more frames is less than a specified non-persistence duration threshold (T1), wherein the persistence duration requirement is that a cumulative time duration (TTOT) encompassed by the one or more frames occurs only after the at least one time period has elapsed and exceeds a specified persistence duration threshold (T2) characterized by T2>T1.