Robust Grey-Scale Image Watermarking Using Two ...

1-D Walsh coding was presented to improve the robustness of digital image watermarking. In this paper, an efficient, new two dimensional Walsh code approach to copyright protection is proposed. The proposed technique inserts the Walsh coded binary bits of handwritten signatures in the DCT blocks of the 512×512 grey scale colour images. The embedding procedure is realized by transforming the host image into DCT domain. The low frequency coefficients of the DCT blocks undergo modification by inserting the Walsh coded watermark. The algorithm is blind and does not require the original image in the extracting process. The distortion caused by the watermarking algorithms is invisible and it has been assessed by using the PSNR and SSIM. The empirical results show the effectiveness of the proposed scheme to accomplish high imperceptible quality watermarked image and smooth watermark detection. The robustness of the algorithm has been verified using Stir Mark benchmark and other conventional attacks. The watermark recovery is achieved 100% even by using significant JPEG compression and some common signal processing attacks.