are simply a series of addresses whether generated by visible or invisible portions of the spectrum the method for generating the inner and outer boundary lines encompassing the background to subject transition area is not limited to any specific number of spectral zones for simplicity the colors red green and blue will be used hereafter in describing the method for automatically generating these boundary lines 0018 fig1 is the block diagram of one embodiment of the invention identifying the steps in the process of automatically generating inner and outer boundary lines at the inner and outer edges of the subject to background transition area each step is described and explained as follows upper case letters r g b identify red green and blue signals in the clear frame a clear cl frame is an image frame in which all foreground subject matter is cleared from camera view lower case letters r g b identify signals in a current cu frame that includes the subject a number of factors can cause the rgb levels in the background of the current frame to differ from the rgb levels in the previously stored clear frame including a change of line voltage on the set lighting lamps interference beat or modulation from standard fluorescent lamps and scene balancing adjustments that are performed automatically within the video camera such as automatic iris automatic gain and automatic black offset at any moment during a scene the line voltage powering set lighting.