The Research And Development Of JPEG Image Compress Technology Based On WAP Gateway

Recent years, with the rapid development of mobile Internet, the load capacity ofWAP(Wireless Application Protocol) Multimedia gateway(Multi-service)which is the mediabetween Internet and Wireless Network is facing test. On the other hand, with the continuousinnovation of Multimedia, photograph technology, the amount of image data in the internetgrew rapidly, and about70%in it is JPEG format. Therefore, It is significant that optimizethe process flow of JPEG image in Multi-service Proxy.In general, Multi-service proxy must complete the decoding process of the JPEG file,before it process the JPEG data steam, and then turn to the content adaptation flow, finally,encode and send the image data. There are following three reason need to be optimized in thisprocess:1. Waste of bandwidth resource. Although there are abundant broadband resource in theera of3G, but the bandwidth is hard to support mass of image data.2. I/O thread will block the other threads, when MSP transports a large JPEG image.CPU will be scheduled to the other thread until MSP finish the process flow of the image data.3. The current JPEG standard library is not perfect, it only support streaming decodingbut not encoding.Because of above background, this paper attempt to explore how to optimize JPEGimage content adaptation process of Multi-service Proxy. On this basis, this paper finish thefollowing work:1. Design and Implement the streaming JPEG to solve the issue of latency of mobileuser, when MSP transports a large JPEG image.2. Design and Implement scaling a JPEG image in frequency domain to solve the issuethat when scale a JPEG in time domain, the time complexity is too large.3. Complete the performance test, and demonstrate the test data.