脊波变换域盲数字水印方案

鲁棒性是数字水印最基本的要求之一,水印嵌入的位置和强度直接影响到水印的鲁棒性.本文提出了一种新的基于离散脊波变换(DRT)的盲水印算法,利用脊波变换对线状奇异性的稀疏表示特性,找出图像中视觉重要信息,并将水印嵌入其中,提高了水印的鲁棒性.根据图像局域脊波系数来选取水印嵌入强度,保证了水印的不可见性.水印提取不借助于原始图像,能实现盲提取.在强烈攻击的情况下,实验结果表明,此方法对JPEG压缩、滤波、噪声、裁剪等攻击具有很好的鲁棒性.

Blind digital watermarking scheme in ridgelet domain

Robustness is one of the most basic requirements for digital watermarks. Embedding position and embedding strength will affect the robustness of watermarks. In this paper, a new blind watermarking scheme was proposed in ridgelet domain. We firstly partitioned the image into blocks and used the directional sensitivity and anisotropy of ridgelet transform in order to obtain a sparse image representation, where the most significant ridgelet coefficient represented the important vision information of images. And then watermarks were embedded in the most important ridgelet coefficient, which improved the robustness of watermark. However the embedding strength affects the invisibility. In this paper, the embedding strength was adaptively determined according to local ridgelet coefficients, which ensured the invisibility of watermark. The watermark recovery did not require the original image and watermarks could detect blindly. Experimental results show the proposed watermarking scheme is robust to JPEG compression, filter, noise, cut and other intensive attack.