本文提出一种用于版权通知和保护的多功能彩色图像水印算法.其基本思想是在彩色图像的不同区域分别嵌入可见水印和不可见水印.根据归一化块方差特性在空域中自适应地嵌入可见水印,以实现版权通知功能.利用抖动调制技术在离散余弦变换域(DCT)中嵌入可盲抽取的不可见水印,以实现版权保护功能.实验结果表明,嵌入的可见水印很难去除,不可见水印对彩色图像的质量影响很小,并对常规处理具有较好的鲁棒性.

A multipurpose color image watermarking algorithm for copyright notification and protection is proposed.The basic idea is to embed the visible and invisible watermarks into different blocks of the color image,respectively.Based on the characteristics of normalized block variances,the visible watermark is adaptively embedded in spatial domain to achieve the goal of copyright notification.By utilizing the dithered modulation technique,the invisible watermark that can be blindly extracted is embedded in the DCT domain to obtain the aim of copyright protection.Simulation results show that the visible watermark is hard to remove by common operations,the impact of the invisible watermark on the color image quality is slight,and the invisible watermark is robust to common signal processing operations.