COMPOSITE FEEDBACK PREDICTIVE CODE COMMUNICATION SYSTEM FOR A COLOR TV SIGNAL INCLUDING A CARRIER CHROMINANCE SIGNAL

For code transmission of a television signal, an interframe predictive code communication system is already known wherein interframe or previous-frame feedback is resorted to on producing prediction error signals by using samples of a previous frame as predicted samples in view of the interframe correlation of the television signal. The interframe predictive code communication system is effective for a television signal for a slowly moving object. For raising the efficiency of the code transmission, a composite feedback predictive code communication system is also known wherein use is made of the interframe prediction and of intraframe prediction which may be either intersample or previous-sample feedback or interline or previous-line feedback or both. A conventional composite feedback predictive code communication system is effective for a monochrome television signal because encoding is carried out with the interframe redundancy removed by the interframe prediction and with the intraframe redundancy avoided by the intraframe prediction. However, it is impossible to apply the interframe predictive and the composite feedback predictive code transmission directly to frequency-multiplexed color television signals. The present invention provides a composite feedback predictive code communication system directly applicable to a color television signal including a carrier chrominance signal component and compatible to monochrome television signals. Responsive to signal samples of a color television signal including a carrier chrominance signal, a predictive encoder produces quantized prediction error signals in compliance with a first transfer characteristic (1 - P1) (1 - P2), wherein minima which are substantially equal to zero are taken by the absolute value of 1 - P1 in the neighborhood of frame frequency and by the absolute value of 1 - P2 in the neighborhoods of zero frequency and subcarrier frequency. Responsive to the quantized prediction error signals, a predictive decoder produces reproduced samples in compliance with a second transfer characteristic of the inverse of the first transfer characteristic.