Adaptively controlled encoding for interframe DPCM

An adaptively controlled encoding scheme for application in interframe differential pulse-code modulation (DPCM) is described. The scheme reduces the data rate to substantially below the symbol entropy by using the finite residual correlation between the prediction errors. Simulation with teleconferencing image sequences demonstrates that with such an adaptive encoding scheme, a rate reduction of over 37% can be easily achieved. The principle of adaptive encoding, its application in interframe DPCM image coding, and hardware versus coding efficiency trade-offs are described. Various schemes ar presented. How the adaptively controlled encoding can be combined with run-length coding is also shown.<>