一种基于分布中心的矢量数据零水印算法

摘要

针对鲜有零水印算法能同时适用于点、线、面矢量数据版权保护,提出一种基于分布中心的矢量地理空间数据零水印算法.首先,对矢量数据进行格网划分;其次,计算格网内每个点到其算数平均值中心的距离,并将得到的距离序列与距离平均值进行比较,大于等于距离平均值,则记为1,否则为0;然后,统计格网内的0和1数量的多数,记为0或1,以此生成空间数据特征值;最后,将该特征值与置乱后的二值水印进行异或,构造出零水印图像.实验表明,文中算法能同时适用于点、线、面矢量数据,并且对常见的平移、缩放、裁剪、格式转换、随机删点等攻击鲁棒性好.%Few zero-watermark algorithm can be applied to all type vector data for copyright protection.This paper proposes a zero-watermark algorithm for vector data based on distribution center.Firstly, the vector data is divided into grid.Secondly, the distance of each point to the arithmetic mean center in the grid is calculated and distance sequence is compared with the average distance.If the distance is greater than or equal to the average, the record is 1, otherwise 0.Then, the majority of the 0 and 1 is counted in the grid and 0 or 1 is recorded to generate characteristic of data.Finally, the XOR operation is done between the shuffled watermark image and the characteristic value, then the zero-watermark image is obtained.Experiments show that the algorithm can be applied to all type vector data, and also has good robustness to common attacks including translation, scaling, cropping, format transformation, random delete point and so on.