PRIVACY ZONE ALGORITHM FOR PTZ DOME CAMERAS

摘要

The present invention advantageously provides a means by which the privacy zone on a PTZ camera can be maintained so that an object in the camera's sight is always masked or covered. An algorithm which remembers the defined privacy zones as an area in space marked by four rays touching the four corners of the marked zone and having absolute Pan, Tilt angular coordinates is presented. The privacy zone is initially defined by a rectangle on the screen with known pixel co-ordinates which are translated into angular coordinates. Then, when the camera moves and prepares to display a new screen, the privacy zone is superimposed on the object to be masked. Locating the object and displaying its privacy zone is done by translating the absolute angular coordinates of the original privacy zone into pixel coordinates. Additionally, multiple privacy zones can be displayed on one camera screen.