摘要伴随着新一轮信息的到来,图像信息在我们日常生活、工作中的作用越来越大,而我们在收到图像信息时,对图像信息的分辨率和还原度要求也越来越高,这也是现在通信领域的一个难题。传统的图像压缩编码虽然可以在一定程度上把冗余的部分较从图像信息中很好的去除掉,但很容易导致失真。小波变换不仅可以有效地避免了传统算法的很多不足的地方,而且相对于原来的图像压缩更加灵活。当前,基于小波分析的图像压缩已经占据了电子图像通信领域的主导地位。86211
本文对图像压缩编码技术进行研究,并详细研究了小波图像压缩编码。通过把小波变换以前和小波变换之后所对应的子带图像的特点进行分析和比较,得出小波变换的原理是使用部分小波系数对图像进行重新构造,来完成压缩。目前常见的有两种图像压缩算法:EZW 算法和SPIHT算法,两种算法各自都有自己的特点,在不同的压缩要求下有着不同的应用。因此,本文主要对EZW算法和SPIHT算法进行研究,并通过Matlab实验仿真证实EZW算法实现简单,但是编码效率比较低;SPIHT算法相对于EZW算法运算上会显得复杂,但是编码后的图像压缩率和还原度都有非常明显的提升。
毕业论文关键词: 小波变换;图像压缩;EZW;SPIHT;Matlab
Abstract With a new round of information revolution, the image information in our daily life, more and more work, and we are in receipt of the image information, the image information of the resolution and the reduction degree requirements are increasingly high, which is now the communication field of a problem。 The traditional image compression encoding can the redundant part from the image information well removed to a certain extent, but easily lead to distortion。 The wavelet transform can not only effectively avoid many traditional algorithm deficiencies, and compared with the original image compression is more flexible。 At present, has occupied a dominant position in the field of electronic image communication and image compression based on wavelet analysis。
This paper focuses on the research of image compression encoding technology, and a detailed study of wavelet image compression encoding。 By analyzing and comparing the characteristics of the corresponding wavelet transform before and after wavelet transform subband image, wavelet transform is the principle that the image was reconstructed using the wavelet coefficients, to complete compression is a common。 Two kinds of image compression algorithms: EZW algorithm and SPIHT algorithm, the two algorithms have their own characteristics, there are different applications in different compression requirements。 Therefore, this paper focuses on the research into the EZW algorithm and SPIHT algorithm, and through the Matlab simulation experiment proved that EZW algorithm is simple, but the encoding efficiency is relatively low compared with the EZW algorithm; SPIHT algorithm will be complex, but the image encoding after compression rate and reduction degree have very obvious improvement。
Keywords: wavelet transform;Image compression; EZW; SPIHT;Matlab
目录
第一章 绪论 1
1。1研究背景 1
1。2 图像压缩编码技术的发展史 2
1。3 基于小波变换的图像压缩编码技术的发展与现状 3
1。4 基于小波变换的图像压缩编码技术的研究热点与发展趋势 4
1。5 主要研究内容 5
第二章 图像压缩方法概述 6