基于DWT和DFRFT相结合的图像数字水印算法

Image digital watermarking algorithm based on the combination of DWT and DFRFT

数字水印技术是一项用于版权保护和信息隐藏的重要技术。本文提出了一种改进的数字图像水印嵌入和提取算法。该算法的正弦信号,通过FRFT变换成两个不同阶次的微分。再将微分信号采样后叠加加权作为伪随机序列,该序列用于置乱水印图像。将原始图像采用DWT两层分解后将HL分量再做DFRFT变换,然后将置乱的水印图像嵌入。实验验证可以看出本文提出的离散小波变换和离散分数傅立叶变换(DWT-DFRFT)算法,体现了较好的鲁棒性。

Digital watermarking is an important technique used tor copynght protection ana nlalng mrormanon in a^g~taL meam objects. In this paper, a new digital image watermarking embedding and detecting method are presented. The algorithm made sinusoidal signal by fractional with two differential orders. The sampled signals of the differential signals were superimposed as the pseudo-random sequence which was used to scramble the watermark-image. We used DWT domain to embed the watermarking into the original image in such a way that it is imperceptible by human visual system. The proposed Discrete Wavelet Transform and Discrete Fractional Fourier Transform （DWT-DFRFT） algorithm gives best robustness over the other algorithms under these attacks.