An IWT based blind and robust image watermarking scheme using secret key matrix

Abstract

In this paper, the authors have proposed a binary watermark embedding approach for protecting the copyright ownership of the gray-scale images. The proposed watermark embedding process is realized in integer wavelet transform (IWT) domain to defend the robustness property. Instead of inserting the watermark bits directly in the coefficients of cover media, an indirect embedding mechanism is proposed with the reference to a logistic map based secret key matrix which enhance the secrecy of the proposed embedding approach. Initially, the approximate sub band of the IWT transformed cover image is selected with the intention to embed the watermark. Later, a secret key matrix of size corresponding to the approximate sub band of the cover image is formed using the logistic map with secret parameters. During the watermark embedding process, the approximate sub band is modified indirectly with reference to the secret key matrix and a proposed division table. The scheme is tested on a set of standard images and satisfactory results are achieved. In addition, the proposed schemes is also able to extract the watermark information in blind manner. Also, the scheme is comparable with some other related schemes. Finally, the proposed watermarking scheme is able to survive the watermark even after performing certain types of image manipulation attacks.