Patent ID: 6476858
Filing Date: 2002-11-05
Classification: G08B,H04N

Abstract:
A video monitoring system, comprising:a plurality of video cameras, each outputting a video image; a personal computer interfaced to each camera, a display device, video digitization circuitry and an event trigger, the computer being operative to perform the following functions: a) receive and digitize the video images from each video cameras, b) display the video images in separate windows on the display device, and c) perform a predetermined function in response to the event trigger, wherein the event trigger is generated by: applying a map having a plurality of masking cells to a new video image and to an old video image so that the new video image and the old video image each include a plurality of unmasked cells completely surrounding the masked cells, wherein the map has the same dimensions as the new video image and the old video image, and wherein the masked cells inactivate a fixed area within the new video image and the old video image, comparing the plurality of unmasked cells of the new video image with the plurality of unmasked cells of the old video image to detect any changed cells in the new video image, and applying a filter to the changed cells that eliminates any changed cells in the new video image that are not surrounded by other changed cells in the new video image, and wherein the event trigger is generated when at least one changed cell remains after applying the filter.