一种基于Harris特征点和DWT-SVD的图像盲水印算法

目的针对第2代数字水印技术,提出一种基于Harris特征点和DWT-SVD的图像盲水印算法。方法提取归一化图像的Harris特征点;选取部分稳定特征点来确定要嵌入水印的特征区域;将特征区域作一次小波分解得到的低频子带,对低频子带进行分块,并对每一块进行奇异值分解,通过对每块中最大奇异值进行加权的方法来嵌入水印信息。结果 PSNR值均大于45 d B,NC值接近于1,说明该算法具有可行性。结论该算法对剪切攻击具有很好的鲁棒性,同时该算法也能很好地抵抗噪声、中值滤波攻击、提高亮度攻击、降低亮度攻击、基本图像处理操作的攻击。

An Image Watermarking Algorithm Based on Harris Feature Points and DWT-SVD

For the second generation of digital watermarking technology, this paper proposes a DWT image watermarking algorithm based on Harris feature points and singular value decomposition. First the Harris detector was utilized to extract steady feature points from the standard image. Then wavelet decomposition was conducted for the local feature regions to obtain low frequency sub-bands. These sub-bands were then divided into blocks. Singular value decomposition was conducted for each block. The watermark information was embedded by weighing the maximal singular value in each block. PSNR was not less than 45 dB and NC value closed to 1, indicating that the method was feasible. In conclusion, the algorithm has very good robustness to shear attacks. Meanwhile it can resist common signal processing attacks, such as noise, median filter, improved the brightness, reduced the brightness, and JPEG compression.