Internet上图象渐进传输的研究

The Research of Image Progressive Transmission on Internet

在Internet环境中 ,每个用户所占用的网络带宽是不同的 ,并且随着网络状况的动态变化而变化 ,不同用户对图象的质量要求也不一样 ,因此要求服务器端的图象编码器必须具有高度的适应性。1 993年 ,Shapiro提出的小波零树编码算法是一种非常有效的基于小波变换的图象编码方法 ,该算法编码器输出的比特流是按其重要性排序的 ,是对原图象一种渐进的二进制表示。在该算法的基础上 ,提出了一个适合Internet环境下的静态图象渐进传输解决方案 ,最后给出了实验结果。

In a Internet environment, bandwidth of each user is heterogeneous and may change according to current network condition and different user requires different image quality, so a highly scalable image coder is required in the server end. In 1993,Shapiro showed a very successful image coding algorithm named Embedded Zerotree Wavelet(shorted for EZW) which is a very effective image coding method based on wavelet transform, the output bit stream of this coder is ordered by its importance and can be regarded as a progressive binary representation of source image. Base on his algorithm, this paper provides a still image transmission method suitable for Internet environment.