Matlab圖像去噪算法的研究.doc

摘 要 在信息化的社会里，图像在信息传播中所起的作用越来越大。所以，消除在图像采集和传输过程中而产生的噪声，保证图像受污染度最小，成了数字图像处理领域里的重要部分。 本文主要研究分析邻域平均法、中值滤波法、维纳滤波法及模糊小波变换法的图像去噪算法。首先介绍图像处理应用时的常用函数及其用法；其次详细阐述了四种去噪算法原理及特点；最后运用Matlab软件对一张含噪图片（含高斯噪声或椒盐噪声）进行仿真去噪，通过分析仿真结果得出：均值滤波是典型的线性滤波，对高斯噪声抑制是比较好的；中值滤波是常用的非线性滤波方法，对椒盐噪声特别有效；维纳滤波对高斯噪声有明显的抑制作用；对小波系数进行阈值处理可以在小波变换域中去除低幅值的噪声和不期望的信号。 关键词：邻域平均法；中值滤波；维纳滤波；小波变换 Abstract In the information society, the image in the information transmission is used more and more widely. Therefore, ensuring the minimum of the noise and pollution in the process of image collection and transmission became an important part of the field. This paper mainly analysis and discuss the neighborhood average method, median filtering method, wiener filtering method and the fuzzy wavelet transform method of image denoising algorithm. Firstly introduce the common image processing functions and its applications. Secondly elaborate the principles and characteristics of the four denoising algorithm. Finally using Matlab software to a noise images (including gaussian noise or salt pepper noise), and getting some conclusions from the simulation denoising analysis: average filtering is typical of linear filter, which is better used for gaussian noise. The median filter is a common nonlinear filtering method, especially effective to salt pepper noise. Through wiener filtering, the gaussian noise is inhibited obviously. Wavelet coefficients threshold processing in wavelet domain can remove noise and the the signal which is not expect. Key words：Average neighborhood；Median filter；Wiener filtering；Wavelet transform 目 录 第1章 概 述 1 1.1 课题研究背景 1 1.2 图像去噪的研究现状 1 1.3 本文主要工作 2 第2章 Matlab简介 4 2.1 Matlab概况 4 2.2 Matlab发展过程 4 2.3 Matlab的语言特点 5 2.4 Matlab图像处理常用函数 7 2.5 本章小结 8 第3章 图像去噪算法 9 3.1 图像噪声概述 9 3.2 邻域平均法图像去噪 10 3.3 中值滤波法图像去噪 14 3.4 维纳滤波法图像去噪 19 3.5 基于模糊小波变换法图像去噪 21 3.6 本章小结 26 第4章 基于Matlab的图像去噪算法仿真 27 4.1 邻域平均法的仿真 27 4.2 中值滤波的仿真 28 4.3 维纳滤波的仿真 31 4.4 基于模糊小波变换法的仿真 32 4.5 几种去噪方法的比较分析 35 4.6 本章小结 36 结 论 37 参考文献 38 致 谢 39 概 述