基于函数映射机制的鲁棒性二重数字水印算法

针对二重数字水印嵌入信息量相对较大及其水印之间相互干扰的特点，提出了一种基于函数映射机制的二重数字水印算法。将第一、二重水印建立某种函数映射关系，在嵌入水印时，只需嵌入一份水印样本，并结合小波变换、离散余弦变换和奇异值分解技术，将水印嵌入在寄主图像中。仿真实验结果表明：该算法不仅具有很好的透明性，而且对各种常规数字信号处理和几何攻击也有很强的鲁棒性。

Robust Dual Digital Watermarking Algorithm Based on Function Mapping Mechanism

For the dual digital watermarking, the information capacity to be embedded is relatively large and the two watermarks easily interfere with each other. Aiming at these characteristics, this paper proposes a robust dual digital watermarking algorithm by means of function mapping mechanism. In this algorithm, a kind of function mapping relationship between the first-level and the second-level watermarks is established. Thus, only one watermark is required during embedding watermarking. Then, the watermark is embedded into host image by using the discrete wavelet transform, discrete cosine transform and singular value decomposition technology. Experimental results show that the proposed scheme has better transparency, and stronger robustness to some common digital signal processing and geometrical attacks.