基于SVD、DCT和RSA加密数字水印算法研究

Research on Watermarking Algorithm of Image Using SVD、DCT and RSA Encryption

提出了一种基于SVD、DCT、RSA加密数字水印算法,该方法是将载体文档图像做8*8块的DCT变换,水印图像进行了Arnold处理,将水印图像嵌入到变换的SVD正定矩阵中,修改中频域频谱系数,同时对文档使用RSA算法进行加密,含有水印的图像经IDCT变换存成嵌入水印的图像。通过提取变换域的SVD,提取数字水印,经过RSA算法加密后解密该文档,在经过猫脸逆变换处理得到数字水印图像,水印图像的提取IDCT实验结果表明,本文算法具有安全性高、鲁棒性强以及嵌入水印较好的视觉隐蔽特性、算法处理速度快等特点。

In this paper,a watermarking algorithm of doc image using SVD、DCT and RSA Encryption was presented.In this algorithm,covered image is transformed into 8＊8 block using in DCT,the watermarking image is transformed in Arnold transformation,in the second stage the covered image is used to modify the matrix of SVD,and middle frequency coefficient was modified and at the same time the document is encrypted using RSA algorithm.The covered image with watermark is transformed into embedded image by IDCT.The watermark image is extracted in transformation of SVD,the encryption doc is decrypted and watermark image is transformed in inverse arnold transformation.The Experiment results of watermark extraction show that image transformation has better safety,robustness,and high better vision masking,and more fast in process algorithm.