Abstract: Aiming at the problems that the copyright identifications are mostly binary image with single structural information, and the robustness of geometric attacks is poor in existing zero watermarking algorithm, this paper proposes a color zero watermarking algorithm in RGB spatial. Firstly, convert the color carrier image and color watermark into R, G, B color components. Then, perform Arnold scrambling and block processing on the three spatial components of the carrier image. Secondly, calculate the mean value for each sub-block of each channel, constitute a decimal mean matrix, convert the mean matrix to an 8-bit binary matrix, and generate three color channel binary feature matrices. At the same time, the scrambled color watermark component is converted into 8-bit binary watermark information, and the three binary feature matrices are respectively XOR with the carrier image to generate three zero watermarks. Finally, the three zero watermarks generate a color zero watermark by inverse coding technology. Experimental results show that the algorithm can effectively resist non-geometric attacks, geometric attacks and combined attacks. Compared with the similar zero watermarking algorithms, the algorithm has better robustness and higher security.

Key words: RGB space, color zero watermarking, robustness, Arnold scrambling

摘要： 针对现有零水印算法使用的版权标识大都为结构信息单一的二值图像，且对于几何攻击鲁棒性差等问题，提出一种RGB空间彩色零水印算法。首先将彩色载体图像和彩色水印转换成R、G、B颜色分量，其次对载体图像三个空间分量分别进行Arnold置乱和分块处理；然后计算每个颜色通道各个子块的均值，构成十进制均值矩阵，将均值矩阵转换成8位二进制矩阵，分别生成三个颜色通道的二进制特征矩阵；最后将置乱后的彩色水印分量转换成8位二进制水印信息，分别与载体图像的三个二进制特征矩阵异或生成三个零水印，将三个零水印通过逆编码技术生成彩色零水印。实验结果表明，算法能够有效地抵抗非几何攻击、几何攻击和组合攻击，与相似的零水印算法相比，鲁棒性更好，安全性更高。

关键词: RGB空间, 彩色零水印, 鲁棒性, Arnold置乱