H.263 based facial image compression for low bitrate communications

The International Telecommunication Union (ITU-T) has put forward a recommendation H.263 "Video Coding for Low Bitrate Communication". This recommendation specifies a coded representation that can be used for compressing the moving picture component of audiovisual services at low bitrates. The basic configuration of the video source coding algorithm is based on ITU-T recommendation H.261, but with some improvements and changes to improve performance and error recovery. We develop several methods to improve the encoding speed which is important for the applications such as real time videophone and video-conferencing. These methods focus on the basic encoder operations of motion compensation, discrete cosine transform (DCT) and bit rate control for facial images. Some experimental results using these methods are discussed.