摘要
提出一种适合于栅格地理数据版权保护的变换域盲水印算法。在分析栅格地理数据及其水印特征的基础上,引入数学映射思想,依据分块数据经傅立叶变换后的首个系数构建数据-水印同步函数,在水印信息与分块数据之间建立起稳健的具有双向定位性质的对应关系;采用量化思想设计水印嵌入规则,并在同步函数的指导下,将对应的水印信息嵌入分块数据中频分量系数的相位和幅值,在水印嵌入过程中建立了水印误差控制机制,以满足栅格地理数据精度要求。实验结果表明,所提出的算法既具有较好的不可感知性,又能有效保证栅格地理数据质量,尤为重要的是,算法对常规攻击、几何攻击及一定程度的复合攻击等具有好的鲁棒性,适用于栅格地理数据的版权保护。
A blind watermarking algorithm in transform domain is proposed to protect the copyright of raster getigraphic data. Firstly,the characteristics of raster geographic data and effects on watermarking algorithm are analyzed. Then, the mathematical technique of mapping is introduced to build synchronization function. According to the first ct^efficient of blocking data which has transformed by discrete Fourier transform,the synchronization function is built to establish a stable bidirectional connec：tion between watermark information and blocking data. Finally,on base of the synchronous function, watermarking information is embedded into the intermediate frequency coefficients of blocking data by the way of quantitative mechanism.In the process of ^imbedding watermark,the data error caused by embedding is controlled by the established mechanism of watermark error control to satisfy the precision characteristics of raster geographic data. Experiments on the proposed watermarking algorithm are performed in invisibility,error statistics,robustness comparison between the proposed algorithm and previous productions. The experiment results show that the proposed algorithm is not only robust against common attacks and complex attacks such as cropping processing, cutting, z ^^ om,rotation etc, but also effective in guaranteeing the requirement of data accuracy for raster ge -ographic data. Therefore,with a strong feasibility and significance in practical applications, the proposed algorithm can be applied to protecting the copyright of raster geographic data.
出处
《地理与地理信息科学》
CSCD
北大核心
2016年第5期65-70,共6页
Geography and Geo-Information Science
基金
地理信息工程国家重点实验室开放研究基金项目(SKLGIE2015-M-4-5)
中国博士后科学基金项目
国家自然科学青年基金项目(41401518)
关键词
栅格地理数据
数字水印
同步函数
量化思想
误差控制
raster geo- data
digital watermarking
synchronization function
quantitative mechanism
error control
