摘要对数字图像进行压缩编码操作是为了保证其在通信过程中实现高速稳定地传输。压 缩编码技术是根据信息学原理，如应用统计学原理或运算变换等操作来去除图像数据中 的冗余以达到数据压缩的目的。本文分析了图像压缩编码系统的基本理论，并从保真度 和压缩比两个性能参数上对灰度图像的压缩编码进行了讨论。基于保真度的压缩编码研 究是以三种无损压缩算法(Huffman 编码、无损预测编码、行程编码)为例。而基于压缩比 的编码方法研究则讨论了主成分分析法和 DCT 变换这两种限失真压缩编码方法。文章通 过编写 matlab 代码对灰度图像进行压缩处理，分析并比较解压图像的峰值信噪比（PSNR）、 压缩比以及编码时间等参数。实验结果表明有损压缩的压缩比相对于无损压缩有大幅度 提高，并且在主成分分析压缩方法中，通过选择合适的主成分个数，原始图像数据的还 原可以达到很好的效果。79964

毕业论文关键词 冗余、灰度图像、保真度、压缩比、Huffman、DCT

毕 业 设 计 说 明 书 外 文 摘 要

Title Study of digital image compression coding algorithm

Abstract Digital image compression coding is to ensure that the image data can be transmitted stably with high speed in the process of communication。 The technology of encoding compression is based on the information theory to make the data compressed by using some methods ,such as statistics theory and transformation, to remove or reduce the redundant data。 This paper introduced the basic theory of image coding and it discussed the fidelity and compression ratio in gray image coding。 The discussions about the fidelity took three lossless compression methods as examples, they were Huffman coding, lossless predictive coding and run length coding。 The study based on the compression ratio did researches on the principal component analysis(PCA) and the discrete cosine transform (DCT) coding, which were two types of lossy coding methods。 In this paper, the gray image was compressed through the matlab programming and the main performance indexes of image compression (like PSNR, rate and encoding time) were analyzed and made comparisons。 The simulation results showed that the compression rate can be improved greatly when using the lossy compression methods, compared with the lossless coding ways。 What is more, the restoration the original image data can be of high quality when applying the PCA coding method with a suitable number of principal components。

Keywords  Redundancy, Gray image, Fidelity, Ratio, Huffman, DCT

本科毕业设计说明书 第 I 页

目 次

1 绪论 1

1。1 研究背景 1

1。2 压缩编码的重要意义 1

1。3 国内外研究现状 2

1。4 本文的研究工作 3

2 基本图像压缩编码方法 5

2。1 图像压缩可行性分析 5

2。2 图像压缩编码方法 5

2。3 图像编码模型 6

2。4 图像压缩技术性能指标 7

2。5 本章小结 9

3 压缩算法研究 。。 10

3。1 基于保真度的压缩编码算法 。