Brightness Distortion in Television

Brightness distortion, a term analogous to harmonic distortion in sound transmission, refers to nonlinearity of the brightness transfer characteristic of a television system. This characteristic is the curve relating the brightness values in the televised object to the corresponding brightness values in the received image. Brightness distortion is defined as occurring whenever the brightness transfer characteristic departs from a straight line passing through the origin corresponding to black in object and image. This paper offers a unified theory of brightness distortion, suggests a rational terminology, and presents a graphical method of evaluating the visual effects of the distortion.