摘要
提出一种在矢量地图中自适应嵌入水印算法.对地图按坐标分块,根据每块顶点密度和DFT(离散傅里叶变换)中频系数幅值大小对每个矩形块水印嵌入强度进行自适应调整,并在DFT变换中频系数幅值中嵌入水印信息.实验表明,该算法能够在保证矢量地图数据精度的同时,有效增强水印鲁棒性.
An adaptive algorithm for a watermarking of a vector map is presented. By dividing the map into blocks, the intensity of watermark is modulated adaptively according to the density of vertices and the DFT （ discrete Fourier transformation） amplitude of middle frequency coefficients in each block, then the watermark is embedded in DFT middle frequency coefficients. Experimental results show that the algorithm can ensure the accuracy and enhance the robustness of the vector map.
出处
《应用科技》
CAS
2009年第7期47-50,65,共5页
Applied Science and Technology
关键词
版权保护
数字水印
矢量地图
DFT变换
copyright protection
digital watermarking
vector map
discrete Fourier transformation
