A realtime model‐based facial image synthesis based on multiprocessor network

Model‐based image coding has been highlighted recently as a high‐efficiency coding method for TV telephone and TV conference systems. In a model‐based coding system, an ultralow‐rate image transmission is realized by obtaining common models of a facial image at both sides of a communication and by transmitting only modification parameters between them. However, it is difficult to realize a realtime processing of a model‐based coding with a conventional iterative‐processing type computer since the amount of material to analyze and synthesize at both sides is very large. Realtime processing is absolutely necessary to realize a practical system using this method, i.e., highspeed processings at both the transmitter and receiver are required. This paper describes a realtime facial image synthesis method based on a multiprocessor construction with a transputer. The transputer is a microcomputer having a communication capability with multiple processors and 10 MIPS CPU performance. Using this system in a pipeline processing with 20 processors, it is possible to synthesize realtime facial images at a rate of about 16 frames per second. If only a part around the lips is transmitted, it is possible to synthesize an image at a rate of about 40 frames per second with a network using five processors.