光学学报, 2008, 28 (s2): 308, 网络出版: 2009-01-05
基于相息图和小波变换的数字水印
Digital Watermarking Based on Kinoform and Wavelet Transform
信息隐藏 数字水印 相息图 相位恢复 小波变换 information hiding digital watermarking kinoform phase retrieval wavelet transform
摘要
提出一种基于相息图和小波变换的数字水印方案。利用迭代相位恢复算法将水印图像编码为相息图, 然后将经权重因子调制后的相息图嵌入到宿主图像的三层小波低频系数中, 完成整个水印嵌入过程。在水印提取阶段, 对宿主图像和含水印图像进行三层小波分解, 将得到的低频系数对应相减提取出水印相息图, 然后对此相息图进行傅里叶变换操作, 取其振幅即可提取原始嵌入的水印图像。针对不同权重因子的水印系统, 详细分析和讨论了所提出水印方案的隐蔽性和稳健性。计算机仿真结果验证了该数字水印方案的可行性。
Abstract
A novel digital watermarking scheme based on the kinoform and discrete wavelet transform (DWT) is proposed. The watermark image to be hidden is first encoded into a kinoform by utilizing the iterative phase retrieval algorithm in a virtual lens system. The weighted kinoform is embedded into the low-frequency DWT coefficients (LL3) of the host image to accomplish the watermark embedding process. In the process of watermark extraction, the embedded kinoform can be extracted by subtracting the corresponding DWT coefficients of the host image, from that of the watermarked image. Then, the original hidden image can be retrieved by taking the real amplitude of Fourier transform (FT) information for the extracted kinoform. The robustness and imperceptibility of watermarked image with the different weighting factors are demonstrated and analyzed in detail. The feasibility of proposed approach have been verified by computer simulations.
祁永坤, 彭翔, 关颖健, 高志, 孟祥锋, 秦琬. 基于相息图和小波变换的数字水印[J]. 光学学报, 2008, 28(s2): 308. Qi Yongkun, Peng Xiang, Guan Yingjian, Bruce Z. Gao, Meng Xiangfeng, Qin Wan. Digital Watermarking Based on Kinoform and Wavelet Transform[J]. Acta Optica Sinica, 2008, 28(s2): 308.