一种超复数频域的有意义数字水印算法

针对彩色载体图像,提出了一种彩色图像超复数频域的水印算法。它通过对彩色载体图像进行快速超复数傅氏变换,在超复数频域选择合适频段嵌入水印,并且修改其对称系数的值,保证了嵌入水印图像仍然可以用彩色图像的红、绿、蓝三色进行传输。分析表明提出的方法通过超复数傅氏逆变换,可以把水印带来的误差扩散到整幅图像,并且是分散到红、绿、蓝三色的各个分量上,从而实现数字水印的不易感知性和安全性的良好结合。本算法还提出了对水印数据进行交叉冗余嵌入的规则,以进一步提高数字水印的鲁棒性。最后给出了实验结果,验证了本算法的优越性。

Content based image watermarking algorithm in hypercomplex frequency domain

Based on the hypercomplex Fourier transform(HFT),a novel frequency domain watermarking algorithm for color host images is proposed.The watermark data are embedded into some proper hypercomplex frequency components and their corresponding HFT coefficients are modified to fulfill the symmetry constraint.The prerequisite,the watermarked host image in spatial domain should also be transferred in red,green,and blue channels,of embedding watermark data into the hypercomplex frequency domain is obtained.The analytical results show that the image distortions from the watermark are spread throughout the whole image and are spread into the three channels of a color host image by a hypercomplex inverse Fourier transform.So the proposed watermarking algorithm can realize a good combination for the imperceptibility and security of the watermark.Moreover a cross redundancy embedding rule is also proposed to improve watermarking robustness further.Experimental results verify the effectiveness and superiority of the proposed algorithm.