基于LWT-QR分解和Laplacian Pyramid的水印算法  

Watermarking Algorithm Based on the LWT-QR Decomposition and Laplacian Pyramid

作　　者：陈青[1] 吴继伟[1] 孙峰[1] 

机构地区：[1]上海理工大学,上海200093

出　　处：《包装工程》2018年第3期217-222,共6页Packaging Engineering

基　　金：国家高技术研究发展计划(863)(2012AA050206);上海自然科学基金(12ZR1420800);上海理工大学国家级项目培育基金(16HJPY-MS06)

摘　　要：目的为了提高数字水印的鲁棒性和不可见性,提出一种基于Laplacian Pyramid和LWT-QR分解的水印算法。方法首先对宿主图像进行2层Laplacian Pyramid分解,取其第2层Laplacian残差图像进行一层LWT分解,取其低频子带进行大小为4×4的无重叠分块处理。然后,基于提升小波系数的相关属性,再对每个选中的低频子块进行QR分解,取分解后R矩阵的第1行为目标进行水印的嵌入,同时对水印进行Arnold置乱,置乱后的水印图像嵌入到R矩阵的第1行元素中。结果嵌入水印后图像的PSNR能够达到45 d B,而且该方案对常见的信号处理攻击有较好的鲁棒性,NC均值在0.9以上。结论理论分析和大量的实验数据表明,该方案能够很好地改善图像操作过程中的鲁棒性和不可见性。The work aims to improve the robustness and invisibility of digital watermarking and put forward a kind of watermarking algorithm based on the Laplacian Pyramid and LWT-QR decomposition. First, the two layers＇ Laplacian Pyramid decomposition of host image was conducted. The second layer of Laplacian residual image was taken for a layer of LWT decomposition, and the low frequency subband size was subject to the 4×4 non-overlapping block processing. Then, based on the related properties used to improve the wavelet coefficient, the QR decomposition of each selected line frequency sub-block was done. The watermark was embedded with the first line of the decomposed R matrix as the target. Meanwhile, Arnold scrambling of the watermark was conducted. The scrambled watermark image was embedded into the first-line elements of R matrix. The PSNR of the watermarked images could reach 45 d B, and such scheme had better robustness against the common signal processing attacks with the average NC values all above 0.9. Theoretical analysis and a lot of experimental data show that the scheme can well improve the robustness and invisibility in the operation process of the image.

关 键 词：LAPLACIAN PYRAMID LWT-QR分解 鲁棒性 数字水印 

分 类 号：TS206[轻工技术与工程—食品科学]