多描述编码与互联网视频传输技术的研究

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1、天津大学博士学位论文多描述编码与互联网视频传输技术的研究姓名：蔡灿辉申请学位级别：博士专业：信号与信息处理指导教师：丁润涛20021201ABSTRACTThisdissertationdealswithseveralkeytechniquesforvideotransmissionintheIntemet，includingwaveletmotioncompensationvideocoding，multipledescriptionCOding，andtransmissionbit-ratecont

2、rol，etc．First，thepaperpresentsaschemeoftheX．treeimagecoding．AnX-treeiSahierarchicalquadtreewhosea11descendantsareinsignificant。anditisusedtodenote2-Dclusteredinsigniticantwaveletcoefficientsofanimage．ThecodingefficiencyoftwoproposedX—treebasedcodingschem

3、es．theprogressiveX—treeapproachandthesimplifiedX-treeapproach，aremuchbetterthallthatoftlleEZWBasedontheseapproaches．anall-phasewaveletmotioncompensationfralneworkwithfastarithmeticX-treevideocodeciSproposedtorealizehi窟}lefficiencyand10Wdistortionvideocod

4、ing．Theall—phasewaveletmotioncompensationsuccessfullyeliminatestheskiff—variantpropertyofthewavelettransform，andOUtrlerformsthespatialmotioncompensationanddirectwaveletmotioncompensation．Second，amultipledescriptioncodingapproachbasedonsignificantcoeffici

5、entdecompositionispresented．whereeachsignificantwaveletcoe瓶cieutiSdecomposedintotwotoefficients．OneiSmadefromthebitsintheoddpositions，whereas．theotherismadefromthebitsintheevenposifions．Thesetwotypesofcoe伍cientsarethengroupedintotwosub．signals，whichfol'n

6、ltwodescriptionsofcodeddataandtransmittedoverdifferentchannels．Ifonedescfiptionis10st．itCanberecoveredbytheprimaryandredundantcodingfromanotherdescription．RedundantcodingrateiSreducedbYUsingthestructureConsistencybetweentWOsub．signalsandtheperformanceiSi

7、mproved．Experimentalresultshaveshownthattheperformancesoftheproposedschemearebetterthanthoseoft11epolyphasetransformandselectivequantizationone．Third．alinearmodelbetweenthepercentageofsigniticantcoe伍cientsintotalpixelsandoutDutbit．rateisdevelopedbyanalyz

8、ingR-Dcharacteristicsofwavelettransformedimages．Giventhepercentage，aquantizationstepsizeCanbcfoundeasilyfromahistogram，SOtheproposedalgorithmcailcontroloutputbitrateeasily,quickly,andaccurately．Itcarle笳cientlymakeuseofchan