Rejection of light intrusion false alarms in a video security system

DETAILED DESCRIPTION Having thus described the invention, what is claimed and desired to be secured by Letters Patent is: 1.
A video security system visually monitoring a scene and detecting motion of an object within the scene comprising: imaging means continually viewing the scene and producing a signal representative of the scene; processor means processing said signal, comparing the signal representing the scene at one point in time with a similar signal representing the scene at a previous point in time, and identifying those segments of the scene at said point in time which differs from segments of the scene at the earlier point in time; discriminator means evaluating those segments of the scene identified as being different to determine if the differences are caused by surface differences which are indicative of the presence of an intruder within the scene, or lighting changes which occur within the scene and do not indicate the presence of an intruder, if the difference is caused by the presence of an intruder providing an indication thereof; said discriminator means including means comparing pixel elements contained in each segment of the scene at one point in time and corresponding pixel elements contained in a corresponding segment from the scene at an earlier point in time; and said discriminator means determining a ratio of light intensity between each pixel in a segment with each pixel adjacent thereto, and means comparing the ratio values for the pixels in the segment of the scene at one point in time with the ratio values for the pixels in the corresponding segment of the scene at the earlier point in time.
2.
The video security system of claim 1 wherein said imaging means comprises a camera capable of producing an image of a scene.
3.
The video security system of claim 2 wherein said camera is a television camera operating in the visible portion of the light spectrum.
4.
The video security system of claim 2 wherein said camera is an infrared camera operating in the infrared portion of the light spectrum