Watermarking algorithm for vector geo-spatial data based on amplitude of DFT domain
Changqing Zhu · Cehui kexue · 2008
This paper presented a new watermarking algorithm for vector geo-spatial data based on DFT.By the proposed algorithm,the coordinates of specific vertices in vector geo-spatial data are chosen to construct corresponding complex number sequence,which is in turn transformed by DFT.By modifying the amplitude of DFT domain,the N(0,1) distribution pseudo random watermark sequence is embedded into the vector geo-spatial data.The vector geo-spatial data with watermarking can be obtained by inverse discrete Fourier transformation.By comparing the differences between the original vector geo-spatial data and the data with watermark,the information of watermark can be extracted.The experiments show that the proposed algorithm is robust to the attack of vertex deletion,data format transformation,translation,rotation and so on.