Patent ID: 8279283

Claim:
A video surveillance system comprising: a plurality of video cameras, each comprising a field of view, said cameras configured to at least one of zoom for changing the camera field of view, and tilt for rotating the camera about a horizontal tilt axis, and pan for rotating the camera about a vertical pan axis; and a processor configured to: receive a signal indicative of an image of a calibration target in the field of view of a first video camera of said plurality of video cameras at a position defined by a pan parameter, a tilt parameter, and a zoom parameter; recognize the calibration target within the image using the received signal, the calibration target having a property that a calibration target to camera angle can be derived from images of the calibration target; derive a calibration target to first camera angle from the image using the property of the target; transmit the pan, tilt, and zoom parameters and the calibration target to first camera angle to a second video camera of said plurality of video cameras; receive a signal indicative of an image in the field of view of said second video camera at a position defined by said pan parameter, said tilt parameter and said zoom parameter transmitted from said first video camera to said second video camera; recognize said calibration target within the image in the field of view of said second video camera using said received signal of said second video camera; derive a calibration target to second camera angle from the image of said second video camera using the property of the calibration target; determine the location of the first camera relative to the second camera based on the calibration target to first video camera angle and the calibration target to second video camera angle; determine a spatial grid of a location of the first video camera and the second video camera relative to each other camera of the plurality of video cameras based on the calibration target to first video camera angle and the calibration target to second video camera angle; and refining the spatial grid, wherein refining the spatial grid includes: registering a first image of the calibration target captured by the first video camera; registering a second image of the calibration target captured by the second video; and iteratively increasing a zoom factor of the first image and the second image to refine a relative position.