多媒体通信

目录目录..................................................................................................................................................1摘要..................................................................................................................................................2Abstract.............................................................................................................................................31.设计要求......................................................................................................................................42.JPEG图像压缩原理.....................................................................................................................52.1图像压缩技术简介.............................................................................................................52.2JPEG图像压缩基本原理....................................................................................................62.1.1颜色空间转换以及图像分量采样.........................................................................62.1.2离散余弦变换（DCT）..........................................................................................92.2.3系数量化...............................................................................................................102.2.4Zigzag扫描排序....................................................................................................112.2.5DC系数调制编码.................................................................................................122.2.6AC系数调制编码..................................................................................................132.2.7霍夫曼编码...........................................................................................................152.3JPEG压缩要求.................................................................................................................162.4JPEG解码原理.................................................................................................................163.基于MATLAB的算法实现.....................................................................................................213.1JPEG压缩设计.................................................................................................................213.2基于DCT变换系统设计.................................................................................................223.3量化程序设计..................................................................................................................233.4Z扫描系统设计...............................................................................................................243.4霍夫曼编码设计..............................................................................................................254.仿真............................................................................................................................................265.总结............................................................................................................................................286.参考文献....................................................................................................................................29附录1.............................................................................................................................................30附录2.............................................................................................................................................33摘要图像的数字化表示使得图像信号可以高质量地传输，并便于图像的检索、分析、处理和存储。但是数字图像的表示需要大量的数据，必须进行数据的压缩。因此图像压缩编码技术的研究显得特别有意义，也正是由于图像压缩编码技术及传输技术的不断发展、更新，推动了现代多媒体技术应用的迅速发展。本设计在研究JPEG压缩编码对图像数据压缩的基本原理的基础上，设计了JPEG仿真方案和程序实现流程，根据流程图编写了JPEG压缩编码的仿真程序，并利用MATLAB软件对仿真程序进行了调试，验证了JPEG压缩编码对图像数据压缩的可行性。通过运行JPEG仿真程序输出了原图像，重建图像，以及二者的差值图像，通过直观比较，发现经过JPEG仿真程序压缩后的图像仍有很好的视觉效果。通过对输出的压缩比，峰值信噪比等参数的研究，科学的论证了JPEG压缩编码对图像数据巨大的压缩效果以及良好的压缩质量。实验结果表明基于DCT变换的JPEG图像压缩方法简单、方便,既能保证有较高的压缩比，又能保证有较好的图像质量，应用MATLAB仿真出来的结果较好的反应了其编码算法原理。关键词：JPEG，DCT，MATLAB，图像压缩AbstractDigitalimagesthatmakehigh-qualityimagesignalcanbetransmitted,andtofacilitateimageretrieval,analysis,processingandstorage.Butthedigitalimagesthatrequirelargeamountsofdata,thedatamustbecompressed.Therefore,imagecompressioncodingtechnologyresearchisparticularlymeaningful,andbecausetheimagecompressiontechnologyandtransmissiontechnologycontinuestodevelop,updateandpromotetheapplicationofmodernmultimediatechnologytodeveloprapidly.IhaveJPEGcompressionin-depthstudyonthebasicprinciplesofimagedatacompressionbasedonJPEGemulatorhandsdrawnflowchart,flowchartwaspreparedaccordingtoJPEGcompressionsimulationprogram,andthesimulationprogramusingMATLABsoftwarewasdebuggedtoverifytheJPEGcompressionofimagedatacompressionisfeasible.SimulationprogrambyrunningtheoutputoftheoriginalJPEGimage,reconstructedimage,andthedifferencebetweenthetwoimages,byvisualcomparison,foundthroughsimulationprogramcompressedJPEGimageisstillverygoodvisualeffects.Compressionratioontheoutputpeaksignaltonoiseratioandotherparametersofthestudy,scientificproofoftheJPEGimagedatacompressioncodingoftheg