彩色图像水印算法研究

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1、辽宁师范大学硕士学位论文彩色图像水印算法研究姓名：贝依林申请学位级别：硕士专业：计算机软件与理论指导教师：闫德勤20080501ABSTRACTInrecentyears，thespreadoftheInternetandtheadvanceindigitaltechniquesfortransmittingandstoringinformationhavemad．eitpossibletocopyandeditimages，audio，videoandothertypesofmultimediad

2、ata．Multimediadatabydigitalformatcanbeduplicatedwithoutlossofqualityandchangedeasilyatlowcost．Thesesituationscausetheillicitactionssuchasinterception，duplication，misuseandunauthorizedmodificationofinformation．Oneapproachtoaddresstheproblemiswatermarkin

3、gtechnique．Theconceptofdigitalwatermarking·isassociatedwiththedata—hidingtechnique．DigitalwatermarkinghasbeenproposedasawaytoidentifytheSOUrCe，creator，owner，distributor，orauthorizedconsumerofmultimediadata．Inthisthesis，thecurrentwatermarkdevelopingstat

4、us，basiccharactersandproblemsofdigitalwatermarktechnologywereanalyzed，andthegeneralframeofdigitalwatermarkprocessingsystemwasdiscussedandthreewatermarkingschemesareproposed．Inthefirstscheme，presentsacolorimagewatermarkingmethodwithblinddetectionbasedon

5、amplitudemodulation．Onthebasisofthevisualmaskingofhumanvisualsystem，theembeddedpositionswerechosenadaptively．Basically，thewatermarkwasembeddedbymodifyingthepixelvaluesinthebluechannelofanimage，whilethewatermarkretrievalisachieved‘byusingapredictiontech

6、niquebasedonlinearcombinationofnearbypixelvaluesaroundtheembeddedpixels．Weuseatechniqueofgaussianweightingmarksbyaveragingtheluminanceofitsownpixelanditsneighboringpixels，anduseitasanadditionalscalingfactortotunethestrengthofembeddingwatermark．Experime

7、ntalresultsshowthatthepresentedschemeisinvisibleandrobustagainstvarioussignalprocessingsuchascropping，compression，filtering，noiseadding，imageenhancementandgeometricalattacks．Inthesecondscheme，anewalgorithmisproposed；thewatermarklIwasembeddedbymodifying

8、thepixelvaluesinthebluechannelofanimage，whilethewatermarkretrievalisachievedbyusingapredictiontechniquebasedonsupportvectorregressionmodel．Themodelistrainedbylearningtherelationshipbetweentheselectedpixelandstatisticalfeatureofneighbori