摘要
针对二维矢量地图特定的数据结构以及水印嵌入带来的地图变形问题,提出了一种基于视觉感知特性的可逆水印算法。该算法首先基于顶点密度估计策略对矢量地图多边曲线的噪声不敏感区域进行选择;其次为使得水印嵌入带来的扰动最小,选择噪声不敏感区域顶点坐标的小数部分作为载体数据;最后依据水印嵌入阈值选择性修改整数离散余弦变换(DCT)变换后的交流分量(AC)系数值完成水印的嵌入。该水印方案在精确提取水印信息的同时可以完全无损恢复原始矢量数据,因而更加适用于矢量地图版权保护。实验结果表明,该水印方案在保证视觉不可感知的同时具有较高的嵌入容量及较强的鲁棒性。
In view of 2D-vector maps＇ special data structure and map distortion induced by data embedding, the paper presents a perception-based reversible watermarking algorithm. Firstly, the algorithm selects the noise non-sensitive regions of polylines based on the vertex density estimation strategy, and then chooses the vertex coordinates of the noise non-sensitive regions as cover data to minimiza the distortion induced by watermark embedding. Finally, watermarks are embedded by selectively modifying alternating current （AC） coefficients after the integer discrete cosine transform （DCT） according to the predefined threshold. The technique of the reversible watermarking can strictly recover the original cover data, with the watermark being accurately extracted at the same time. Therefore it is more suitable for the copyright protection of vector maps. The experimental results show that the proposed approach can achieve invisibility with high capacity as well as robust to some attacks.
出处
《高技术通讯》
EI
CAS
CSCD
北大核心
2010年第4期342-348,共7页
Chinese High Technology Letters
基金
国家自然科学基金(No.60873138)资助项目
关键词
矢量地图
版权保护
可逆水印
无损恢复
整数DCT变换
vector map, digital rights protection, reversible watermarking, lossless recovery, integer DCT transform
