南京师范大学泰州学院
毕 业 论 文
题 目
学生姓名 学 号 专 业 班 级 指导教师
曹峰 09080324 电子信息工程 信0803 孙剑芬
基于DCT图像压缩编码算法的研究
2012 年 4 月
基于DCT图像压缩编码算法的研究
摘 要
随着科学技术的发展，图像压缩技术越来越引起人们的关注。为此从众多的图像压缩编码标准中选取了基于DCT变换的图像压缩编码算法进行研究，并通过对此对比分析各种软件特性选取了MATLAB进行仿真实验。
首先说明了图像压缩在现代通信中的必要性和可行性，然后讲述了MATLAB及其图像处理工具箱的相关知识，并对基于DCT变换的图像压缩算法进行详细研究，重点介绍了压缩编码的具体过程和方法，详细介绍了编码中DCT变换，量化，DCT编码等模块的原理以及各模块的功能分析。最后应用了MATLB进行了实验仿真并分析结果得出结论。
实验结果表明基于DCT变换的图像压缩方法简单，方便，即能保证有较高的压缩比，又能保证较好的图像质量，应用MATLAB仿真出来的结果比较好的反应了其编码原理。
关键词：图像压缩；DCT；MATLAB；图像处理工具箱
I
DCT-based image compression encoding algorithm
Abstract
Image compression technology has been growing concern with the development of science. To this end a large number of images from the selected coding standard DCT-based image compression research, and comparative analysis of various software features through the selection experiment MATLAB simulation.
First, note the image compression in modern communications and the necessity and feasibility, and then tells the MATLAB and its Image Processing Toolbox of relevant knowledge, and DCT-based image compression algorithm is studied in detail, focuses on process and method of compression ，describes theory and mathematical derivation the DCT transform coding，quantization，entropy coding，as well as the functional analysis of each module. The last application of MATLAB to Simulation and experimental results concluded.
Experimental results show that the results table DCT-based image compression method is simple and convenient, not only guarantee a higher compression ratio, but also to ensure both better image quality, MATLAB simulation results reflect a better algorithm principle.
Keywords: image compression；DCT；MATLAB；Image Processing Toolbox
II
目 录
摘 要 .................................................................................................. I Abstract .............................................................................................II 第一章 绪论 ....................................................................................... 1
1.1课题背景及研究意义...................................................................................... 1 1.2图像压缩技术的研究现状与发展趋势.......................................................... 2 1.3论文主要内容与结构安排.............................................................................. 3
第二章 所用开发工具简介................................................................. 4
2.1 MATLAB软件简介............................................................................................ 4 2.2 MATLAB的优势特点........................................................................................ 4 2.3 MATLAB在图像处理中的应用........................................................................ 7
第三章 常见的图像压缩方法 ............................................................. 8
3.1 引言................................................................................................................. 8 3.2 RLE(Run Length Encoding)压缩算法......................................................... 8 3.3 LZW编码.......................................................................................................... 9 3.4哈夫曼(Huffman)编码.................................................................................. 10 3.5基于小波的图像压缩技术............................................................................ 10 3.6变换编码.........................................................................................................11 3.7基于分形的图像压缩与编码.........................................................................11 3.8本章小结........................................................................................................ 12
第四章 基于DCT变换的图像压缩方法 .......................................... 14
4.1引言................................................................................................................ 14 4.2离散余弦变换原理........................................................................................ 14 4.3基于DCT的图像压缩编码步骤.................................................................... 16
4.3.1 基于DCT图像压缩编码流程图........................................................ 16 4.3.2 DCT系数的量化................................................................................. 16
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