Abstract: With the goal of achieving both robustness to unreliable channels and adaptivity to client bandwidth heterogeneity and network congestion, the authors explore constructions for layered multiple description codes, where base layer descriptions can be transmitted to low bandwidth clients, while both base and enhancement layer descriptions can be transmitted to high bandwidth clients The multiple description coding is used to resolve the problem of transmission over unreliable channel Directional wavelet transform is selected to remove redundancy among neighboring pixels in order to high coding efficiency Through comparisons with other traditional multiple description the new architecture can obtain better quality of image in unreliable network channels

Key words: multiple description coding, layer coding, directional wavelet transform

摘要： 为了达到在不可靠网络中传输和自适应带宽的目标，提出了一种新的多描述图像编码。该方法采用不同的分层比例实现分层传输，将基本层传输给低带宽的客户端，而基本层和增强层传输给高带宽的客户端；采用多描述编码方法解决不稳定网络信道中传输的问题。在图像编码过程中，采用自适应的方向小波变换来消除图像相邻像素间的冗余信息以提高压缩效率。实验结果表明该算法具有很好的鲁棒性，在高误码率信道上相对于传统的多描述图像编码可以得到更好的重建图像质量。

关键词: 多描述编码, 分层编码, 方向小波变换