学科分类
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1 个结果
  • 简介:In2011,Chanproposedanimageauthenticationmethodbyproducingtheparitycheckbitsfrompixelswhosebitshavebeenrearranged.Duetothisrearrangement,thevalueofthemost-significantbitofeachtamperedpixelcanbedeterminedaccordingtoitsparitycheckbits.Withthehelpofthemost-significantbitofthepixel,thepixelcanberecoveredbyselectingtwopossible(7,4)Hammingcodewords.However,ifthedistancebetweentwoHammingcodewordsiswithinacertainrange,incorrectselectionmayoccur.Chan'smethodaddedoneadditionalbittoindicatethecorrectone.Itistrivialthatthismaydegradethequalityoftheauthenticatedimage.Inthispaper,wegroupfourmost-significantbitsintodifferentgroupstoformamappingcodebookandthemappingcodebookisusedtoproduceauthenticationdatainsteadofthe(7,4)Hammingcodebook.Theexperimentalresultsshowthattheproposedmethodhasagreaterabilitytorecovertamperedareas.

  • 标签: 图像像素 验证方法 奇偶校验位 身份验证 汉明码 码字