基于遗传算法的鲁棒数字图像水印研究

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1、天津大学博士学位论文基于遗传算法的鲁棒数字图像水印研究姓名：魏志成申请学位级别：博士专业：通信与信息系统指导教师：戴居丰20070501克服了原有嵌入和提取方法存在水印泄漏的缺点。用Arnold变换预处理水印图像后，利用遗传算法搜索对保真度影响较小的重要系数，同时优化了本质上矛盾的保真度和鲁棒性，Arnold置乱和遗传算法的随机性也提高了水印的安全性。关键词：数字水印；遗传算法；鲁棒性；保真度；盲水印ABSTRACTWiththewidespreaduseofIntemetandthedevelopmentinc

2、omputerindustry,greatconvenienceisprovidedforinformationstorage．Asabyproduct，thedigitalmultimediainformationwithoutpermissioncallbecopiedandredistributedeasilyfromtheIntemet，whichrendersgreatlosstobothcopyrightownerandproducer．Socopyrightprotectionhasbecomeas

3、eriousissue．Asapotentialmeasuretosolvetheproblem，digitalwatermarkingisbecomingahottopicintheresearcharea．Duringthetransmissionofdigitalproduct，somedataprocessingistheprevalent,suchasJPEG,filter,noiseandSOon．Sincealltheprocessesarethreateningthesecurityofthewa

4、termarkedproduct,inordertoprotectthewatermarkeffectively,theresearchonrobustwatermarkingschemeisimportanttoboththeresearchfieldandthebusinessapplicationofdigitalwatermarking．BycombiningtheGeneticAlgorithm(GA)，applyingtheinnercharacterofdigitalimage，andtakinga

5、dvantageofexistedresearch，somerobustdigitalwatermarkingmethodsareproposedagainstdifferentattacks．WehopeitCanprovideanewwayforthefullapplicationofthedJigitalwatermarkingscheme．First,Weproposeanadaptivegeneticalgorithm(AGA)fordigitalwatermarkingscheme．Theadapti

6、vecrossoverandmutationoperatorshavebeenproposedtoincreasetheglobalresearchanddecreasethecomplexity．Theabilityofglobaloptimaztionisprovedbytheoreticialderivationandexperiments．TheFitnessfunctionhasbeendesignedtoavoidsettingtheweightsofdifferentparameters．Secon

7、d，adaptivegeneticspreadsprctrumwatermarking(GSSW)modelin8×8DCTdomainhasbeenmadebasedontheclassicalspreadsprctrumwatermarkingmethod．TheGAisusedtooptimizethebestwatermarkimbeddingbandsforimprovingthesecurity,fidelityandrobustness．Therelativeembeddingmethodischa

8、ngedtoabsolutemethod,andwedesignthefitnessfunctiononlyincludingrobustness．ExperimentsshowthattherobustnessisimprovedobviouslyandtherandomcharaterofGAmakethewatermarkingmethodmoresecure．Th