【作者】 杨凤禄；

【导师】 张淑清；

【作者基本信息】 燕山大学 ， 检测技术与自动化装置， 2006， 硕士

【摘要】 在傅立叶分析基础上发展起来的小波技术,提供了一种自适应的时域和频域同时局部化的分析方法。通过伸缩和平移等运算功能进行多尺度细化分析,能够有效地从信号特别是非平稳信号中提取信息。因此,小波技术成为数字图像处理及压缩编码的有力工具,也是近年来研究的热点。本文首先对数字图像压缩的必要性和可行性进行了分析,并对传统压缩编码方法进行了比较和综述。在简要介绍小波变换与时-频分析后,较详细地阐述了二维小波分析和二维图像的多分辨率分析,并对数字图像压缩中小波基的选择问题进行了深入的探讨,其中包括小波基的性能分析和评价小波基的标准。本文的重点是小波变换在数字图像压缩中的算法研究,因此对嵌入式零树小波编码进行了深入的研究,并给出了试验结果。本文设计了一种基于子块运动补偿的小波视频图像压缩方案,把多子块运动矢量的快速计算方法运用到空间域运动补偿中,使帧间差值图像主要集中在低频分量上,而高频子带将出现更多的零。这样,使用嵌入式零树小波编码来对帧间差值图像进行编码,可以实现视频图像的高效压缩,在解码时又可以得到良好的视频效果。实验结果表明,这是一种可行有效的方法。最后,本文对构成实时视频压缩系统的五个单元进行了芯片选型和设计;对压缩系统的软件进行了设计;给出了以专用图像处理芯片ADV601LC为核心的实时视频压缩系统的设计方案。系统很好地完成了视频图像的实时压缩,且压缩比高、重建图像质量好。更多还原

【Abstract】 The wavelet technology, which developed on the base of Fourier analysis,offers a self-adaptive localization analysis method for a given signal in bothtime domain and frequency domain. Through extension and translationoptions and multi-scale analysis, it can extract helpful signal informationeffectively from signal, special no steady signal, so wavelet technology hasbecome a powerful tool for digital image processing and compression and hasbeen hot point studied in recent years.This paper analyzes the necessity and feasibility for images compressionat first, and then makes a comparison and summarization for the traditionalcompression methods. The paper introduces simply wavelet transform andtime-frequency analysis, elaborates 2-D wavelet transform and 2-D imagemulti-resolution analysis in detail, and makes some discussions on the waveletbases selection in digital image compression, which includes the performanceanalysis and evaluation criteria of wavelet bases. The paper studies thoroughlyembedded zero tree wavelet coding which is very important in digital imagecompression coding methods, and displays the experiment results.This paper designs the wavelet video image compressing system basedon sub-block motion compensation. The fast searching method ofmulti-sub-block motion vector is used in space-domain motion compensation,so the luminance images between frames concentrate mainly on low frequencyand a lot of zeros appear on high frequency. Embedded zero tree wavelettransform encodes the luminance images between frames, so it can realize theefficient compensation of video image and get the good visual results indecoding image. The experiment results show that it is a feasible and efficientmethod.At last, the selection of chips and designs structures for the five unitswhich composite the real-time video compression system are designed, andthe software design for the compression system is also presented. The designscheme for real-time video compression system based on the special imageprocessing chip—ADV601LC is described. So the system can finish real-timevideo compression well and compression rate is high and the reconstructionimage is clear.更多还原