基于纹理特征定位的数字图像水印算法

提出一种基于图像纹理特征锁定水印嵌入位置的水印算法。利用Canny算子在非采样Contourlet变换最高阶方向子带内筛选图像的纹理特征，将强纹理特征的位置作为水印嵌入的索引点。对非采样Contourlet变换的低频子带进行一级小波分解，在小波细节子带上分割N个圆环(N为水印信息长度)区域，根据索引位置在每个圆环区域内自适应地重复嵌入水印。仿真实验表明，该算法不仅具有较好的透明性，而且对图像处理和几何攻击均具有较好的鲁棒性。

Watermark Algorithm for Digital Image Based on Texture Feature Orientation

A novel watermark method based on the texture of image is proposed. In the finest directional subband of the nonsubsampled Contourlet transform, the coordinate of the coefficient with the richest texture feature by using Canny operator is selected as the index coordinate to be embedded watermark. The three subbands are obtained by applying DWT to the low frequency subband and divided into N circuses which are as many as the pixels of watermark image. Watermark is done by altering the coefficients of the subbands, and every bit of the watermark is inserted repeatedly in a cirque area. Experimental results show the proposed algorithm has good transparency and is very robust to common image processing and geometric attacks.