Patent ID: 6462774
Filing Date: 2002-10-08
Classification: H04N

Abstract:
A computerized light monitoring system for use in combination with a video surveillance system that includes a surveillance camera producing video signals corresponding to light levels within a defined field of view, said monitoring system comprising:a video signal input pathway for receiving video signals from the surveillance camera; a digitizer combined with the signal input pathway for translating video signals into digital light level data; a digitizer controller combined with the digitizer for selecting light level data corresponding to predetermined sample points within the field of view; a first memory combined with the digitizer and digitizer controller for storing selected light level data; a second memory combined with the processing unit for storing normal operation settings programmed into the monitoring system; a loss of video signal detector combined with the video signal input pathway and digitizer controller for detecting a loss of video signals from the video camera; a processing unit having a data input pathway and a data output pathway combined with the digitizer, digitizer controller, and first and second memories, said processing unit detecting degradation of light levels within a field of view, detecting black level conditions, and detecting a loss of video signal from the system and producing an output signal over the data output pathway corresponding to the condition detected; an alarm signal generator combined with the processing unit and being capable of generating at least one alarm signal; and timing circuitry combined with the processing unit for monitoring a durational requirement associated with an alarm condition.