图像置乱及基于奇异值分解的水印算法研究

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1、西南交通大学硕士学位论文图像置乱及基于奇异值分解的水印算法研究姓名：郑文生申请学位级别：硕士专业：密码学指导教师：史燕20070501西南交通大学硕士研究生学位论文第

2、l页AbstractTheappearanceofInternetandthewidelyuseofcomputersopennewavenuestotheacquisition，theexchangeandeventhediffusionofthedigitalmultimediadata．Inthemeantime，theproble

3、msofnetworksafetycomeup．Anybodycanstandtogain，reproduceandreworktheoriginalworksbyInternet，whichseriouslyinfringeonthecopyrightoftheauthors．Nowadays，thecopyrightprotectionofdigitalproduct，suchpracticalproblem．callsforimmediateaction．Undersuchcircumstance

4、s，watermarkingtechnologyhasemergedaccordingly．Itisthetechniquethatprovestheownerofcopyrightbyusingthewatermark，whichisembeddedintheoriginalwork．Stillimageisusedastheresearchobjectinthisthesis，mainlyresearchcontentisasfollow．First，jresearchandrealizationo

5、falgorithmoftheimagescramblingarediscussedinChapter3．Algorithmofscramblingthatisbasedonchaosispresented．Firstly，theauthorUSeSchaossequencethatproducesbyLogisticmappingtorealizescramblingofallimagebychangingthepositionsofitspelspoints．ThentheauthorUSeSChe

6、byshevchaoticsequenceandLogisticchaoticsequencetorealizethegraylevelscramblingbychangingthepixelsvalue．Thesimulationsuggestthatthisalgorithmhassuperiorsecurity，betterscramblingresult，andmoreefficientandlessoperation．Second，thepaperintroducessafetyanalysi

7、softwokindsofwatermarkalgorithmthatisbasedOnsingularvaluedecomposition(SVD)．Andthispaperpointsoutthepotentialsafetyhazardofsuchmethods，andgivesthemethodofestimatingembeddingstrengthorquantizedvaluetorealizethewatermarkattack．Theexperimentalresultsshowtha

8、ttheattackalgorithmiseftectiveandavailableintime．Third，therealizationofdigitalwatermarkingalgorithmbased0n西南交通大学硕士研究生学位论文第1．I．I页quantizationofsingularvaluesinwaveletdomainlSemphasizedinChapter5，Inthispaper，analgorithm—amodifiedwatermarkalgorithm。whichisb

9、asedOUBlock·SVD，isproposedonabasisoftraditionalwatermarkalgorithmofSVD．Thisalgorithmhastwomajordifferencesbetweentraditionalone：first，watermarkadoptsgreylmageinsteadofbinaryimage；second，OUthisalgorithmcanstandagainstthepre