一种矢量线数据零水印算法

A zero-watermarking algorithm for vector geo-spatial data based on logistic chaotic mapping and DFT

为了满足矢量地理空间数据高精度和零扰动的实用性需要,该文提出一种零水印算法。首先利用Logistic混沌映射置乱原始水印图像;然后对原始矢量线数据进行离散傅里叶变换,获得离散傅里叶变换后的相位值,并将相位值由弧度值转换为角度值;接着随机选取均匀分布的角度值,向下取整后转换为相应的二进制形式,得到二值矩阵;最后将置乱后的水印图像与由相位值构成的二值矩阵进行异或操作,从而构造出零水印图像。实验结果表明,该算法能够抵抗常见的平移、缩放等几何攻击,并且对数据格式转换攻击、投影变换攻击具有较好的鲁棒性。

In order to meet the demand of practicality about high accuracy and zero disturbance for vector geo-spatial data,a zero-watermarking algorithm is proposed.Firstly,the Logistic chaotic method is employed to shuffle the original watermark image;then the Discrete Fourier Transform（DFT）is used to obtained the phase values from original vector linear data,the phase values are converted into angle values from radian values;next some angle values which obey uniform distribution are selected,rounded down and converted into the corresponding binary form,binary matrixes are obtained;the XOR operation is done between the shuffled watermark image and binary matrixes consisting of phase values,and the zerowatermark images are constructed finally.The experiments show that the algorithm can resist common geometric attacks including translation and rotation.It also has good robustness to the format conversion and projection transformation attacks.