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

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.