Efficient Gray Image Watermarking Algorithm Based on DWT-SVD Using Genetic Algorithm

Hybrid domain digital image watermarking scheme using discrete Wavelet Transform (DWT) and Singular Value decomposition (SVD) is proposed in this paper. Original host image is decomposed using DWT to obtain coefficients of approximation sub-band (LL3) and it is selected for watermark insertion. Singular values of watermark image are obtained using SVD operation and scaling factor is used to modify the coefficients before inserting it into LL3 sub-band. Genetic Algorithm (GA) optimizes imperceptibility and robustness by finding best scaling factor and searching apposite location for watermark insertion. Performance measuring metric, PSNR and NCC are used to evaluate imperceptibility and robustness of the watermarked image. Experimental results obtained from simulation prove that the proposed new method is more secure and robust compared to existing approaches.