A new hybrid blind image watermarking technique for content authentication based on LWT & SVD

This paper proposes, a robust digital watermarking technique based on LWT (Lifting wavelet transform) and Singular value decomposition (SVD) for the protection of intellectual rights. The singular values of watermark logo are embedded into the singular values of HH subband which is obtained by 1-level LWT on original image and then SVD. In this scheme, a Digital signature is generated by using secret key and the orthogonal matrices (U & V) which is achieved by performing SVD on watermark image for the security purpose. In the next step, the generated digital signature is embedded into the modified LL_3 and HH_3 subband which is obtained after further decomposition of LL subband by N-level LWT. On the receiver side, before extracting watermark, the digital signature is used for the ownership authentication: If the extracted signature is matched with the generated signature then the process of watermark extraction goes on otherwise is stopped. Thus, the proposed scheme achieves the high robustness against various attacks is analyzed.