Abstract—The modern era of information technology facilitates easy duplication, manipulation and distribution of digital data. This has demanded the certainty for effectively safe guarding the rightful ownership of digital images. Copyright protection and content authentication of digital images have emerged as an imperative concern to content owners and distributors. Digital watermarking provided a potential solution to this issue. The watermarking scheme must possess the characteristics of robustness and imperceptibility to ensure efficient copyright protection. An effective copyright protection is achieved by the incorporation of Human Visual System (HVS) models into watermarking scheme. Recently, interest in watermarking researches are chiefly fascinated by wavelet domain based watermarking schemes. In our earlier work, we have presented an imperceptible and efficient wavelet-based watermarking scheme for protecting the copyrights of images. Here, we have offered a proficient watermarking scheme by effecting some changes to our earlier work. The presented scheme for watermarking incorporates the HVS models into watermark embedding. The biorthogonal wavelet transform with lifting scheme is utilized in the watermarking. The image components for embedding are selected based on the entropy masking. A random matrix is generated on the basis of a key image and is engaged in both embedding and extraction processes. The correlation coefficient computation is made use of in the extraction of watermark. The experimental results illustrate the robustness and imperceptibility of the proposed approach.

Index Terms—Biorthogonal Wavelet Transform, Correlation Coefficient, Copyright Protection, Digital Watermarking, Discrete Wavelet Transform (DWT), Entropy Masking, Human Visual System (HVS), Lifting Scheme, Robust.

V. Padmanabha Reddy, Professor, Department of Information Technology, Vardhaman College of Engineering, Kacharam, Shamshabad, R.R.District, Pincode: 501218, Hyderabad, India. Ph: +91 9490244578. Email: padmanabhareddyphd@gmail.com.
Dr. S. Varadarajan, Associate Professor, Department of EEE, S.V. University College of Engineering, Tirupati, Andhra Pradesh, India. Email: varadasouri@gmail.com.

Cite: V. Padmanabha Reddy and S. Varadarajan, "An Effective Wavelet-Based Watermarking Scheme Using Human Visual System for Protecting Copyrights of  Digital  Images,"  International  Journal  of  Computer  and
Electrical Engineering vol. 2, no. 1, pp. 32-40, 2010.