基于DFT的可控误差矢量空间数据盲水印算法

A Blind Watermarking Algorithm for Copyright Protection of Vector Geospatial Data Under Controllable Errors Based on DFT

摘要: 传统的DFT(discreteFouriertransform)变换域水印算法中,水印直接嵌入变换后的系数,导致矢量空间数据误差较大。针对此类算法的缺点,本文提出了基于DFT的可控误差矢量空间数据盲水印算法。该算法通过放大处理DFT变换系数,将水印嵌入幅度系数和相位系数中,水印提取采用投票原则,无需原始数据的参与。试验表明,水印嵌入矢量空间数据引起的误差很小;水印对数据格式转换及常见的几何变换攻击具有很好的鲁棒性。

Abstract: InDFTwatermarkingalgorithms,thewatermarksareoftenembeddeddirectlyinthetrans formationcoefficients,causinglargeerrorsinwatermarkeddata.Toovercomesuchdisadvantageofthesealgorithms,ablindwatermarkingalgorithmforcopyrightprotectionofvectorgeospatialdatabasedonerrorreductionisproposed.ThisalgorithmamplifiestheDFTtransformcoefficientsandem bedsthewatermarksintheamplitudecoefficientsandphasecoefficientsbyDFTtransform,andthewatermarkisembeddedseveraltimes.Inaddition,thevotingprincipleisutilizedtodetectthewater mark.Nooriginaldataisneededinthewatermarkextractionprocedure.Theexperimentshaveshownthatspatialaccuracyofthewatermarkeddataisacceptableandthealgorithmisrobusttoavarietyofgeometrictransformationattacks.