一种基于HVS和DFT的栅格地图自适应数字水印算法  

An Adaptive Watermarking Algorithm for Raster Map Based on HVS and DFT

作　　者：王志伟[1] 朱长青[2] 王奇胜[1,3] 符浩军[1] 

机构地区：[1]信息工程大学测绘学院,郑州市陇海中路66号450052 [2]南京师范大学虚拟地理环境教育部重点实验室,南京市文苑路1号210046 [3]南新疆测勤队,新疆自治区疏勒县844200

出　　处：《武汉大学学报（信息科学版）》2011年第3期351-354,共4页Geomatics and Information Science of Wuhan University

基　　金：国家863计划资助项目(2006AA12Z223);国家自然科学基金资助项目(40501058)

摘　　要：提出了一种适于数字栅格地图版权保护的离散傅立叶变换域自适应数字水印嵌入算法。该算法通过对数字栅格地图进行分块傅立叶变换和频谱分析,结合人类视觉系统,能够自适应地确定地图的纹理区域,将水印信息以加性法则嵌入到纹理区域的傅立叶变换域中频系数内。不同分块大小的栅格地图水印算法具有不同的鲁棒性。对2×2、4×4和8×8分块的水印算法进行了比较分析,结果表明,2×2分块水印算法不仅具有较好的透明性,而且对诸如叠加噪声、JPEG压缩、几何裁剪、图像增强等攻击均具有更好的鲁棒性,整体性能优于4×4分块和8×8分块算法。An adaptive digital watermarking algorithm based on discrete Fourier transform（DFT） is proposed to protect the copyright of digital raster maps.This algorithm can utilize the human visual system（HVS） and the blocking DFT to determine adaptively the texture region where the watermarking information can be hidden.And the watermarking information is embedded to the middle frequency coefficient of the Fourier transform domain of the texture region.The algorithms with different size blocking（blocks） have different robustness.This problem is discussed,and these algorithms are analyzed with different size blocking,such as the 2×2 blocking,the 4×4 blocking and the 8×8 blocking.Experimental results show that the algorithm with 2×2 blocking not only has the good transparency,but also has the good robustness to the image intensity attack such as cropping,JPEG compression,noise adding,image enhancement,and so on.The algorithm with 2×2 blocking performs better than the algorithms with 4×4 blocking and the 8×8 blocking.

关 键 词：数字栅格地图 傅立叶变换 人类视觉系统 数字水印 自适应 

分 类 号：P208[天文地球—地图制图学与地理信息工程] P237.3[天文地球—测绘科学与技术]