The coding of visual signals to reduce channel-capacity requirements

Present-day communication-channel requirements for the transmission of visual information are based on fixed and independent threshold criteria for spatial, motion and contrast resolution. If, in accordance with the dynamic characteristics of the human sense of vision, time-variant and interdependent thresholds are introduced for these parameters, the required channel capacity may be reduced, provided that it is adaptively assigned to the three parameters as demanded. This concept is developed into an integrated coding system for visual signals, making use also of intraframe and interframe correlations existing in television signals. Although it was possible to establish a formal system design, certain psycho-physical data as well as signal statistics have still to be measured to enable a reliable numerical evaluation of the attainable reduction in channel-capacity requirements.