Analog signal bandwidth compression method and slow scan picture telephone

In this dissertation, a new approach of sending high frequency analog signals, such as video signals through low frequency channels, including ordinary telephone lines, at a low speed is presented. The principle of this approach is described and mathematically proven; a circuit implementing the approach is designed and simulation results are given. A slow scan picture telephone system using this approach is designed as a natural extension of daily used audio telephone.;After reviewing major current achievements in this area, a slow scan analog picture telephone approach is proposed and an analog signal bandwidth compression principle is developed. From this theory a design model for analog video signal is established, which can lead to realization into practical picture telephone products. Based on the model, intra frame and inter frame video signal compression are discussed, a memory management and an audio/video combination method are introduced. Due to the characteristic features of remote communication systems, such as picture telephones, a remote system configuration method is developed to enable a picture telephone system to be automatically configured or reconfigured or upgraded. Finally, a model picture telephone system is designed.;As a conclusion, the idea of analog picture telephone introduced here establishes a platform on which various video/audio processing algorithms and products can be developed. It can interface to either analog or digital transmission channels.