Particle Swarm Optimization for Digital Image Watermarking

The trade-off between the imperceptibility and robustness is one of the most difficult challenges in digital watermarking system. To solve the problem, an optimal algorithm for image watermarking is proposed. The algorithm embeds the watermark by quantizing the wavelet packets coefficients of the image. In the proposed watermarking system, to protect the originality of the watermark image, a scrambled binary watermark embeds in the host image against intentional and unintentional attacks and each bit of the permuted watermark is embedded optimally into selected sub-bands of the decomposed host image by quantization of sub-bands coefficients. From experimental results, it demonstrates the robustness and the superiority of the proposed hybrid scheme.