Mehdi Hajizadeh - Department of Electrical Engineering, Shiraz University of Technology, Shiraz, Iran
Mohammad Sadegh Helfroush
Mohammad Javad Dehghani

This paper proposes an efficient blind watermarking algorithm using distance vector for copyright protection. In this algorithm, the wavelet coefficients from various frequency locations have been grouped into a sequence and named as Group for invisible watermark embedding and extraction. In the next step, after choosing the maximum and second maximum amplitude coefficients of each Group, the distance vector between two coefficients is computed. For embedding bit zero and bit 1, values of the distance vector elements are decreased or increased, respectively. The proposed method, takes advantage of considerable robustness against prevalent attacks. Comparison analysis demonstrates that our method has better performance than the other watermarking schemes reported recently and also watermarked images do not suffer from obvious visual distortion.

Blind watermarking, Copyright protection,Distance vector, Significant coefficients, Wavelet