1、引言目前,随着因特网的普及、信息处理技术和通信手段的飞速发展,使图像、音频、视频等多媒体信息可以在各种通信网络中迅速快捷的传输,给信息的压缩、存储、复制处理等应用提供了更大的便利。同时,也为信息资源共享提供了条件,目前网络已经成为主要的通讯手段。但是,在提供 1. Introduction At present, with the popularization of the Internet, the rapid development of information processing and communication means that multimedia information such as images, audio and video can be rapidly and quickly transmitted in various communication networks, and the information is compressed, stored and copied Processing and other applications provide greater convenience. At the same time, but also for the sharing of information resources to provide the conditions, the current network has become the main means of communication. However, provided