（毕业论文）频域图像增强算法研究

山东科技大学 毕业设计论文

专 业：电子信息工程

题目:基于频域的图像增强算法研究 指导教师 评阅教师

2012年 5 月 25 日

摘 要

图像增强处理技术是图像处理领域中一项基本的，也是很重要的技术，一直是图像处理领域中不可回避的研究课题。而且图像增强是指按一定的需要突出一幅图像中的某些信息，同时削弱或去除某些不需要的信息，使之改善图像质量，加强图像判读和识别效果的处理技术。因为一幅图像总是可能受到各种因素的干扰影响，造成图像质量的下降。图像增强包含两个方面内容：一是消除噪声，二是增强(或保护)图像特征。对图像恰当增强，能使图像去噪的同时特征得到较好保护，使图像更加清晰明显，从而提供给我们准确的信息。常用的图像增强技术各有其特点和效果。

论文在介绍图像频域增强原理的基础上，在频域内通过对低通滤波器、高通滤波器的图像增强进行研究，介绍了相关的理论和数学模型，并给利用MATLAB工具进行实现。实验证明，在质量较差的图像中，选择不同的滤波算法对图像的增强在准确性上均有不同。

关键词：图像增强；滤波；MATLAB。

ABSTRACT

Image enhancement in image processing technology is a basic and very important

technology; the field of image processing has been a research topic cannot be avoided. And it aims to stand out some information of a picture to strength image identification and reorganization. At the same time it can wipe out the information that we don’t need in order to improve the quality of image. This paper addresses image frequency enhancement principle and also researches low-pass filtering, high-pass filtering and homeostasis filtering.Because an image is always possible interference by various factors, resulting in a decline in image quality. Image enhancement includes two aspects: First, eliminate the noise; the second is enhanced (or protected) image features. Appropriate image enhancement, image demising can be well protected at the same time features, to make the image more clearly evident, thus providing us with accurate information. Commonly used image enhancement techniques have their own characteristics and effects.

Paper, introducing the principle of image enhancement based on frequency domain, in the frequency domain through the low-pass filter and high pass filtering enhancement into the study, describes the relevant theoretical and mathematical models and tools to use MATLAB implementation. After filtering through a variety of image comparison, real proof of poor image quality, choose a different algorithm for image enhancement filter of accuracy are different.

Key words: Image enhancement; filter; MATLAB.

目 录

第一章 绪论 ........................................................................................ 1 1.1 课题研究的背景和意义 ............................................................. 1 1.2 国内外研究情况 ......................................................................... 3 1.2.1 图像增强技术国外发展状况 ............................................ 3 1.2.2 图像增强技术国内发展状况 ............................................ 4

第二章 频域图像的原理 .............................................................. 6

2.1 引言............................................................................................ 6 2.2 频域增强定义和步骤 ............................................................... 6 2.3 低通滤波 ................................................................................... 7 2.4 高通滤波 ................................................................................... 8 2.5 同态滤波 ................................................................................... 9 2.6 小结.......................................................................................... 11

第三章 MATLAB基础知识介绍 ................................................ 12

3.1 MATLAB基本知识介绍 ........................................................ 12 3.1.1 MATLAB的概述 ............................................................. 12 3.1.2 MATLAB产生的历史背景 ............................................. 12 3.2 MATLAB语言的特点 .......................................................... 13 3.3 MATLAB在图像处理中的应用 ............................................ 14 3.4 MATLAB软件优点 ................................................................ 15