A robust digital watermarking algorithm based on framelet and SVD

Compared with wavelet, framelet has good time frequency analysis ability and redundant characteristic. SVD (Singular Value Decomposition) can obtain stable feature of images which is not easily destroyed. To further improve the watermarking technique, a robust digital watermarking algorithm based on framelet and SVD is proposed. Firstly, Arnold transform is implemented to the grayscale watermark image. Secondly perform framelet transform to each host block which is divided according to the size of the watermark. Then embed the scrambled watermark into the biggest singular values produced in SVD transform to each coarse band gained from framelet transform to host image block. At last inverse framelet transform after inverse SVD transform to obtain embedded coarse band. Experimental results show that the proposed method gains good performance in robustness and security compared with traditional image processing including noise attack, cropping, filtering and JPEG compression etc. Moreover, the watermark imperceptibility of our method is better than that of wavelet and has stronger robustness than pure framelet without SVD.