Image sequence coding using interframe VDPCM and motion compensation

The techniques of motion detection, interframe linear block prediction and vector quantization have been incorporated into a scheme for encoding monochrome image sequences displaying moderate motion. Data transmission rate reduction is accomplished by identifying and processing only those regions of the image that exhibit noticeable changes between successive frames, by estimating the magnitude of the change through linear block prediction, and by vector quantization of the residuals of linear prediction. A motion-compensated vector DPCM (differential pulse code modulation) system has been designed to incorporate the above mentioned techniques. High compression rates with acceptable visual quality are obtained using robust codebooks based on a mean-squared-error criterion as well as using a perceptually meaningful classification method. Encoding rates under 50 kb/s have been obtained at acceptable visual activity. An edge/shade classification scheme that yields either better quality or lower bit rate has been incorporated