Low Latency Image Compression, Decompression Techniques And System Design

It firstly summarized the present mainstream video compression standard norm, the adoptive main techniques and the application objects. The characteristics of each techniques have also be analyzed and compared. According to the characteristics of UAV (Unmanned Aviation Vehicle) Wireless Video Transmission, the simulation-based test and the performance analysis, which were developed in typical mainstream video compression standardand norm, educes some valuable conclusion. Referring to the conclusion from simulation-based tests, performance analysis and the actual situation, there are three selected system methods to develop hardware principle tests in different levels. They are DSP-based MPEG-2 Program; FPGA-based H.263 Program; M-JPEG-based system Program. The three programs were demonstrated and deeply analyzed in the guide of system key performance parameter. For the integration of the deep analysis and technique level at the present stage, the DSP-based MPEG-2 program was selected as the basical method, on which optimized design, alteration and transplant of new technique are developed to achieve the final performance parameter requirement.The system is based on invariableness data rate wireless LOS (Link Of Sight) datalink and used in realtime video transmission field. Video information enter into control close-loop of UAV (Unmanned Aviation Vehicle) flight attitude, so it requires realtime and is sensitive to video delay. According to that characteristic, the system is adapted and optimized in the fields of hardware structure, coding frame, display synchronization, error control and error tolerance. Especially, in the structure of coding frame, it's quite different from typical MPEG-2 standard norm. Skillful arrangement structure of coding frame can reduce delay and improves video quality. In the situation of high data error rate of LOS (Link Of Sight) datalink, it's used the principle of error control in MPEG-4 and H.264 standard norm to inprove video quality.This project puts forward a clear performance parameter to the system delay, but no precision test system was constructed before. Thus, an integrated test system was specially designed to precisely measure the delay of video compression system after transmission from wireless LOS (Link Of Sight) datalink.Finally, apart from the conclusion, several proposal were put forward to the next study of low delay video compression and decompression technique.