Encoding of videoconferencing signals using VDPCM

摘要

The techniques of motion detection, interframe linear block prediction and vector quantization have been incorporated in this paper, in a scheme for encoding monochrome image sequences for videoconferencing application. Data transmission rate reduction is accomplished by identifying and processing only those regions that exhibit noticeable changes between successive frames, by estimating the magnitude of the change through linear block or vector prediction and quantizing the residual vectors through a vector quantizer. The motion detector uses a modified block matching algorithm to detect the moving blocks. Perceptually-based edge detectors are used to design vector quantizer (VQ) codebooks for different classes of image blocks to achieve better visual quality. Encoding rates under 60 kbps are achieved with acceptable visual quality at nominal computational complexity.