Perimeter surveillance system
First Claim
1. An automatic video intrusion detection system to detect targets comprising intruders moving more than a predetermined distance in a direction from one side to the other of an area to be monitored, said system comprising a television camera disposed to view a predetermined area which includes said area to be monitored, said television camera supplying a video image of said predetermined area to a preprocessor, said preprocessor having means for dividing into a predetermined number of cells a portion of said video image substantially corresponding to said area to be monitored, means for deriving integrated video intensity values for said cells and means for storing said integrated intensity values in an output buffer, said system further comprising computer means for periodically analyzing the values stored in said buffer to detect changes in said values exceeding a predetermined amount and to track changes in values for consecutive cells indicating movement of a target, said computer activating an alarm if changes in more than a predetermined number of adjacent cells are tracked in said direction.
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Accused Products
Abstract
Disclosed is an automatic video intrusion detection system. The system monitors a given area such as between two parallel fences. The image of the given area is divided into an array of cells each approximately equal in size to the image of a man. The video for each cell is integrated, digitized and stored in an array. Changes in cell values are detected and tracked so that changes in, say, 3 adjacent cells in a given direction, indicate an intruder. A microcomputer implements a tracking algorithm. Filtering discriminates against light level changes. The system is simpler than a known one which analyzes grey values of thousands of points in a video field.
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Citations
16 Claims
- 1. An automatic video intrusion detection system to detect targets comprising intruders moving more than a predetermined distance in a direction from one side to the other of an area to be monitored, said system comprising a television camera disposed to view a predetermined area which includes said area to be monitored, said television camera supplying a video image of said predetermined area to a preprocessor, said preprocessor having means for dividing into a predetermined number of cells a portion of said video image substantially corresponding to said area to be monitored, means for deriving integrated video intensity values for said cells and means for storing said integrated intensity values in an output buffer, said system further comprising computer means for periodically analyzing the values stored in said buffer to detect changes in said values exceeding a predetermined amount and to track changes in values for consecutive cells indicating movement of a target, said computer activating an alarm if changes in more than a predetermined number of adjacent cells are tracked in said direction.
Specification