计算机应用 ›› 2005, Vol. 25 ›› Issue (05): 1096-1098.DOI: 10.3724/SP.J.1087.2005.1096

• 图形图像与多媒体 • 上一篇    下一篇

基于非高斯分布和上下文法模型的小波阈值去噪算法

杨黎,庄成三   

  1.  四川大学计算机学院
  • 发布日期:2005-05-25 出版日期:2005-05-01

Wavelet threshold denoising via non-Gaussian distribution and context model

YANG Li, ZHUANG Cheng-san   

  1. School of Computer Science and Engineering, Sichuan University, Chengdu Sichuan 610065, China
  • Online:2005-05-25 Published:2005-05-01

摘要: 提出了一种新的空间自适应小波阈值去噪算法,该算法是基于非高斯二元分布的贝叶斯统计模型和上下文法模型。非高斯二元分布由两个变元和一个参数组成,能够完全体现小波系数之间相关性,这是广义高斯分布所不能体现的特性。上下文法模型是图像编码技术,用来求取小波系数的方差。试验数据显示该算法不仅在直观视觉上去噪效果明显,而且在信噪比方面也要优于SureShrink、BayesShrink、Wiener2等方法。

关键词: 小波阈值, 贝叶斯统计模型, 上下文法模型, 非高斯二元分布

Abstract: A new spatial adaptive wavelet threshold denoising method was presented, which was based on a non-Gaussian bivariate distribution and context model for image denoising inspired by image coding. The dependency between coefficients and their parents was carefully studied and a new distribution model composed of two variables and a free parameter was proposed. Context model is the core method in image coding and is applied in this project to choose the spatial adaptive threshold derived in a Bayesian framework. Experiment results show that this new method outperforms the best of the recently published methods, such as SureShrink, Wiener2, and BayesShrink.

Key words: wavelet threshold, Bayes statistics, context model, non-Gaussian bivariate distribution

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