Videophone with DPCM mode
J.-M. Zhang, Junchen Zhou · 2002
Several high compression rate coding techniques are discussed which are meant to reduce the transmission bit-rate of moving pictures of a videophone to that of a digital baseband of 64 kbps. An experimental system based on a digital pulse code modulation (DPCM) system gave acceptable picture quality at 144 kbps for scenes with moderate motion. The improvement of the system to compress moving images to give a lower bit-rate of 64 kbps is discussed. The main goal is to find a coding method that gives a high compression ratio with low hardware complexity.>