The Design And Implement Of Image Compression System Based On DSP

With the development of image compressing, the bandwidth of image signal processed is largely reduced. The signal processed can be transported in regular communications, such as video meeting, video telephone etc. However the equipments of this image-compressed system are complex, expensive, and still need more channels. And it is enough to transport an immobile image in one second in most practical condition, such as a warehouse, transformer station and so on. In these occasions, it needs a video condensation system ported and can attain clarity images and transfer it with network in this circumstance. It has become an effective necessary to use the video condensation system based on network, especially with the development and prevalence of network technology. The thesis is based on this need to devise and carry out an immobile video condensation system based on DSP.In this thesis, a special effort was made to research these problems such as gathering the video image, designing the DSP application system, realizing the JPEG algorithms with DSP and so on. A kind of portable system image compressing card was designed with TMS320C5409 DSP. The system is an independent instrument, which can do white-black video image digitization, compressing, coding and transmitting the compressed image data to host through the Ethernet controller.This thesis detailed introduces the realization of the system in software and hardware of this system. It takes more care in the systemic research of video image collection, circuit design in DSP practice system, realization of JPEG encoding by DSP and so on. The speed of DCT is the key to decide whether the JPEG can be use in real-time applications. So this thesis introduces a fast arithmetic, Loeffler arithmetic and its realization on DSP. A fast arithmetic in DCT based on DSP is put forward and implemented. Compared with the Loeffler arithmetic based on DSP, it saved 25 percent time approximately.