RDWT and SVD based secure digital image watermarking using ACM

Abstract

In this study, digital image watermarking method based on Redundant Discrete Wavelet Transform (RDWT) and Singular value Decomposition (SVD) is proposed. By exploiting the complexity property of the chaotic signals, which is the main reason of using them in the security applications, the robustness and the invisibility of the proposed method is improved. In the proposed watermarking scheme, RDWT is performed to decompose the cover image into four sub-bands (LL, LH, HL and HH). Then SVD is applied to the LL sub-band of the cover image. The chaotic watermark is generated by applying Arnold Cat Map (ACM) to the original watermark. Finally, singular values of the LL sub-band of the cover image are modified with the singular values of the chaotic watermark according to the embedding process. It is demonstrated via computer simulations that the proposed RDWT, SVD and ACM based digital image watermarking scheme provides better watermark concealment and high robustness against both geometric and image processing attacks. Furthermore, the robustness of the proposed scheme is investigated for different dimensions of the binary watermark logo. It is shown that the robustness of our method is independent of the watermark size.