Digital watermarking algorithm based on singular value decomposition and wavelet transformation

How to prove the robustness of robust watermarking against geometrical attacks is still a difficulty of watermarking researchers. Merely using singular value decomposition or wavelet transform watermarking algorithm has different faults. This paper proposed a novel watermarking based on SVD and DWT, which was robust to common geometrical attacks. In the embedding, the lowest frequency components of the source image which were transformed into DWT were divided into sub-blocks in order to improve capacity of watermarking. Then the watermark is embedded in the singular values of sub-blocks after being Arnold scrambled. And the robustness of watermarking could be improved. Experimental results show that the proposed algorithm can resist many kinds of attacks very well, and has good robustness and invisibility, and solve the contradiction between the robustness and the invisibility.