基于双重频域和离轴全息的鲁棒水印关键技术研究

本研究提出一种既具有鲁棒性又具有安全性的图像及视频水印盲检测算法。在图像水印的实现过程中，载体信号的频域变换采用二维小波变换和离散分数随机变换相结合的双重变换，这将提高水印系统的安全性和鲁棒性。此外，嵌入信息通过二维码进行编码，然后用离轴全息技术将二维码图像信息转变成离轴全息图。采用离轴全息技术可以提高水印系统的鲁棒性、安全性和嵌入容量，并可以实现盲检测。视频水印算法中频域变换采用二维小波变换和三维离散余弦变换以及离散分数随机变换。视频信号的每一帧经过二维小波变换后，对部分子带系数进行三维离散余弦变换。三维离散余弦变换由帧内二维离散余弦变换和帧间一维离散余弦变换组成。对二维小波变换和三维离散余弦变换之后的信号再次进行离散分数随机变换。最后在经离散分数随机变换后的信号上叠加离轴全息信号。这将大幅提高水印系统的鲁棒性和安全性。

This study proposes a robust and secure blind detection algorithm for image and video watermarking.?In the implementation process of image watermarking, the transformations of the carrier signal frequency-domain employ a double transform of two-dimensional wavelet transform and the discrete fractional random transform.That will improve the security and robustness of the watermarking system.Moreover,the embedded information is encoded by two-dimensional code, and then use the off-axis holographic technique to change the two-dimensional code image information into the off-axis hologram.By using Off-axis holographic technology can improve the robustness、security and the embedding capacity of the watermarking system, and can achieve blind detection.The frequency domain transformations of video watermarking algorithm employ two-dimensional wavelet transform、 three-dimensional discrete cosine transform and the discrete fractional random transform.A three-dimensional discrete cosine transform will be done for the part of the coefficients get from doing a two-dimensional wavelet transform for each .frame of the video signal.Three-dimensional discrete cosine transform is composed of intraframe two-dimensional discrete cosine transform and interframe one-dimensional discrete cosine transform.?Do the discrete fractional random transform for the signal transformed by two-dimensional wavelet transform and three-dimensional discrete cosine transform again.Finally,superimpose the off-axis holographic signal on the signal transformed by discrete fractional random transform.This will greatly enhance the robustness and security of the watermarking system.