An Optimized Semi-blind Watermarking Technique for Digital Images using Bat Algorithm

In this paper, Bat Algorithm (BA) is used to optimize the proposed semi-blind watermarking scheme of digital images to attain better imperceptibility and robustness. The insertion of the watermark is performed by normalized block processing (NBP) and hybrid transforms such as IWT, DCT and SVD. The embedding and extraction processes have been performed with the parameters obtained from the bat algorithm. The experimental results prove that this scheme exhibits very good perceptual quality for the watermarked image and better robustness for the watermark. The proposed approach is also superior to the other existing methods in terms of PSNR.