中文摘要：

DFT变换域水印算法在抗几何变换方面具有较好的鲁棒性,而针对线或面数据的水印算法不能直接应用于点数据,因此提出了网格划分的方法,将点数据按空间位置划分为网格,以每个网格中的点为水印嵌入单元,采用DFT变换域算法,应用QIM方法嵌入水印信息,实现了水印信息的盲提取.实验证明,该算法对增加、删除、修改顶点、裁剪、平移、放大、缩小、重排序,格式转换、高斯噪声等攻击具有较好的鲁棒性。

英文摘要：

Robustness watermarking algorithm based on DFT which can resist geometric transfor-mation is better than others,but aiming at the line or polygon data,it can＆#39;t be applied to point data directly.Therefore,a method based on grid partitioning is proposed.Point data are distributed into grids according to their space coordinates,and watermarks are embed into all points of every mesh by using DFT and QIM method.No original datum is needed in the watermark extraction procedure.The experiments show that the algorithm is robust against several of attacks,such as cropping,vertex insertion,removal and modification,translation or scaling transformation,reorde-ring,data format conversion and Gaussian noise,etc.