Abstract: A linear color television compositing system of the "blue backing" type, in which the foreground signal channel is always open. The foreground and background channels are not switched by the edges of the pictorial subject matter.The hue of the colored (typically blue) background is removed by vector subtraction and the luminance thereof by arithmetic subtraction.Flare illumination of the foreground subject(s) from the backing is removed, improving color fidelity.The background pictorial scene that takes the place of the removed colored backing area is linearly turned up or down, allowing shadows of foreground subjects to appear in the background.