水下視頻圖像高壓縮比編碼算法研究.pdf

1、中國海洋大學碩士學位論文水下視頻圖像高壓縮比編碼算法研究姓名：王冰申請學位級別：碩士專業(yè)：控制理論與控制工程指導教師：李慶忠20090601RESEARCHoNEFFICIENTUNDERⅥ編TERVIDEoCoMPRESIoNALGoIUTHMAbstractPeoplehaveincreasinglyrecognizedthattheOceanwhichoccupiesnearly75percentoftheearthsurface

2、，asafoundationofthelifcofhumanbeingsinthefuturewiththedevelopmentofoceanexplorationMeanwhile，theoceanconsideredastheinnerspaceoftheearthplaysanimportantroleinmilitaryaffairsHoweverpeoplehavelimitedknowledgeaboutthedeepoc

3、eanduetothecomplexityofoceanenvironmentInrecentyears，computervisionhasincreasinglybeenusedasasensingmodalityforunderwaterexplorationRemotelyoperatedvehiclesOtOVs)andautonomousunderwatervehities(AUVs)alegenerallyequippedw

4、ithunderwatercamerasROVtransmitsvideothroughtethercable，butthetetherlimitsthepracticabilityandmaneuverabilityoftheROVSAIⅣismoreflexibleandcanexploreinamuchlargerrangeHowever，itneedstotransmitmassivevideoinformationthroug

5、hacousticchannels1f1旭mainobstacleinunderwatervideotransmissionisthelimitationoflowbandwidthofunderwateracousticchannelCurrentvideocodingstandardscannotbeappliedtotheacousticchanneldirectlyTakingaccountofthecharacteristic

6、sofunderwatervideosequenceswhilemaintainingtheacceptableperceptualqualityofthereconstructedimages，thefollowingresearchworkonunderwatervideocodinghasbeencarriedout(1)Underwaterimagespossessthecharacteristicsoflowercontras

7、tlesstexturedetailsandlesscolorinformationduetotheartificiallighteningconditionSOawaveletwarnformbasedpreprocessingstepisproposedn圮proposedpreprocessingstepCanreducetheperceptualredundanciesinunderwaterimagesandtheproces

8、singtimeinthesubsequentcodingproceduresAnefficiemintraframealgorithmisimplementedusingwavelettreebasedwaveletdifferentreduction(WDR)aftertheanalysesandcompariSOnsofcurrentintraframecodingalgorithmsThelowpasssubbandconcen

9、tratingthemostimportantinformationofanimageiscodedbyusinglosslessDPCMbasedentropycodingalgorithmWeencodetheotherhighfrequencysubbandsusingthewavelettreebased、ⅣDRmethodExperimentsshowthattheproposedpreprocessingalgorithma

10、ndintraframecodingalgorithmarefeasibleandCanimprovethecompressingratewhilemaintainingperceptualqualityofimages(2)BasedonthescenariosinOurworkwedevelopafastandrobustglobalmotionestimationmethodtoovercometheproblemsintheex

11、istingGMEalgorithms，thatis，complicatedcomputationandtimeassumingOurmethodestimatesthefinalmodelparametersofimagemotionprojectivemodelparameters，bycombiningtheresultoffeaturepointmatchingandtherefiningofrigidmodelparamete

12、rsItCaneliminatetheincorrectcorrespondencesbetweenimagesandreducethecomputingtimeforestimatingglobalmotionparametersNumerousexperimentsillustratethevalidityofOurmethodinimprovingthecomputingspeed(3)Wrealsoproposeahybridg