为进一步提高数字水印系统的性能,提出一种离散小波变换域中基于奇异值分解和Turbo纠错码的彩色图像盲水印算法.首先对数字水印进行混沌加密预处理,然后进行Turbo编码,再把编码后的水印信息嵌入到彩色图像蓝色分量小波分解后低频子带的奇异值矩阵中.提取水印时不需原始载体图像的参与,更便于实际应用.仿真实验结果表明,该水印算法不可见性较好,且对常见攻击和几何攻击具有较好的稳健性.
In order to improve the performance of digital watermarking system, a watermarking algorithm was proposed for color images based on the combination of discrete wavelet transform, singular value decomposition and Turbo codes. Firstly, digital watermarking was pretreated by chaotic encrypting and Turbo coding; secondly, the blue component of color image was decomposed via discrete wavelet transform; finally, the pretreated watermarking information was embedded into the low frequency band of the blue component which had been DWT of the original image by modifying its singular value. It does not need the original image when the watermarking is extracted, so it can be applied in the practice easily. Simulation results show that the watermarking algorithm has good invisibility and robustness to common attacks and geometric attacks.