作　　者： ; ; ; ; ;

机构地区： 石河子大学信息科学与技术学院

出　　处： 《石河子大学学报（自然科学版）》 2010年第4期510-513,共4页

摘　　要： 为了保护地理数据的版权,根据地理数据所具有的特性,提出了一种基于DCT(discrete cosine transform)的地理数据水印算法。该算法对地理数据进行网格化操作以构造空域,实施DCT变换,轻微修改DCT系数,然后实施逆DCT变换,得到修改后的空域,通过调整地理数据中点的分布情况嵌入水印信息。实验结果表明:本算法能抵抗平移、缩放、旋转和化简攻击。 To protect the copyright of geographical data,a geographical data watermarking algorithm is proposed in this paper considering the characteristics of geographical data.We compute minimum bounding rectangle of the geographical data,divide the geographical data into grids on the boundary of the minimum bounding rectangle,count the number of vertices in all cells and derive a grid weigh array.Discrete cosine transform is applied to the grid weigh array.Watermarks are hidden in the DCT coefficients by modifying the signs of DCT coefficients with middle frequencies.Inverse discrete cosine transform is applied to the modified DCT coefficients and modified grid weigh array is derived.The vertices are redistributed according to the modified grid weigh array.Experiments show that the algorithm is robust against translation,scaling,rotation and simplification attack.

关 键 词： 地理数据 水印 网格化 变换

领　　域： [自动化与计算机技术] [自动化与计算机技术]