Some relations between television picture redundancy and bandwidth requirements

An analysis is presented of the concept of statistical redundancy. It is shown that the redundancy can be separated into two parts, nonpredictive redundancy and predictive redundancy. The nonpredictive redundancy results from the message not possessing the most efficient first-order probability distribution while the predictive redundancy results from the statistical correlation of the present value of a signal with its past history. The analytical procedure presented in this paper is then applied to the television communication problem. The results of this analysis compare very favorably with existing experimental evidence. The analysis indicates that by clever statistical coding, a bandwidth reduction of about two to one might be obtained, although even this modest gain would require complex equipment. The conclusion is reached that the best way of achieving bandwidth reduction in television communication is by cleverly degrading the information in a picture in such a way that the human observer would not notice it appreciably.