基于平衡多小波图像变换的视频多描述编码

Multiple Description Video Coding Based on Balanced Multiwavelet Image Transform

提出了一种新的视频多描述编码方法 ,即基于平衡多小波图像变换的视频多描述编码。首先 ,把图像进行多小波变换 ,然后 ,按照图像多小波变换后子带图像分量的异同重组图像的多小波系数 ,相同分量的多小波系数就构成图像的一个描述。视频的每帧图像都如是处理 ,就得到视频的多描述编码。一个好的视频多描述编码方案应该满足两个基本条件 :各个描述平均分担图像信息和各个描述能够互相差错掩埋。通过统计分析和数学推导发现 ,在目前几种常用的多小波中 ,只有平衡多小波能够满足视频多描述编码的两个条件。本文给出了各个描述之间进行差错掩埋的数学公式 ,并据此提出视频多描述编码的算法。实验结果表明 ,即使在丢失四分之三数据的情况下 ,该算法依然能够以接近 30 d B的

A new MD (multiple description) video coding method is proposed in this paper, which is based on balanced multiwavelet image transform. First, we apply balanced multiwavelet transform to the image, and then, corresponding components of each sub-band are gathered together, so that we decompose the image into 4 MDs. By treating every frame of the video sequences like this, we can get a theme of MD video coding. A practical MD coding theme must satisfy two requirements. Firstly, each description should carry the same amount of information. Secondly, there must be dependence among each description. We find among commonly used multiwavelets, only balanced multiwavelet can satisfy the two requirements. Furthermore, based on the feature of CARDBAL2 multiwavelet and strict mathematical deduction, we find a way to estimate the lost descriptions. The experimental results presented in this paper show that even 75% data of the image is lost, we can still get a recovered image at good quality and the PSNR value is nearly 30dB.