抗高程平移和裁剪的格网DEM盲水印算法  

A blind watermarking algorithm for grid DEM resisting elevation translations and cropping attacks

作　　者：魏征[1] 闫浩文[1] 张黎明 

机构地区：[1]兰州交通大学测绘与地理信息学院/甘肃省地理国情监测工程实验室,兰州730070

出　　处：《测绘科学》2016年第8期170-173,100,共5页Science of Surveying and Mapping

基　　金：国家自然科学基金项目(41371435;41201476);国家科技支撑计划项目(2013BAB05B01);甘肃省科技支撑计划项目(1304GKCA009);甘肃省自然基金项目(148RJZA041)

摘　　要：针对DEM数据水印常见的攻击方式——高程平移和裁剪,该文提出了一种可有效抵抗攻击的格网DEM盲水印算法。该算法考虑了DEM数据的特点,对原始水印进行扩频处理,使其与高程差值形成映射关系;利用相邻格网的高程差值在高程平移攻击中的不变特性,以量化方式将扩频后水印按位嵌入到高程差值中,将扩张的差值分摊到相邻高程的后一位。实验结果表明,该水印算法具有良好的不可见性,对DEM数据精度影响较小,并且对抵抗高程平移和裁剪攻击具有良好的鲁棒性。Elevation translations and cropping are the common means of attack for DEM data watermark,this paper proposed a blind watermarking algorithm for grid DEM that could effectively resist elevation translations and cropping attacks.The algorithm took fully account of the characteristics of DEM data.The original watermark information was processed by the mechanism of spectrum spread in order to form corresponding relationship with elevation difference.Using the invariant feature of elevation difference of adjacent grids in attack of elevation translations,the value of watermark was embedded into elevation difference one by one by quantification manner.Then,the ectatic difference was allocated to the next character of the adjacent elevation.The experiments showed that the algorithm had good invisibility and less effect on the original DEM as well as robustness in resisting elevation translations and cropping attacks.

关 键 词：DEM 盲水印 高程差值 高程平移 裁剪攻击 

分 类 号：P208[天文地球—地图制图学与地理信息工程]