A ROBUST WATERMARKING SCHEME BASED ON DCT, IWT and SVD WITH OPTIMAL BLOCK

Signal processing's impact on development of digital media technologies have become a hot topic. The increased of computer network and the growth of the Internet have facilitated the production and distribution of unauthorized copies of multimedia information (text, image, sound, and video). To ensure multimedia security, researchers are focusing on digital image watermarking. With this new concept, the watermark is not just hiding in an image, but it's marked indelibly. In this paper a robust method of digital images watermarking based on combination of DCT, IWT and SVD is proposed. At first, Visual cryptography is used to encrypt the watermark image. Then DCT is applied to it and to the host image. IWT and SVD are applied on DCT coefficients of both watermark and host images. After that, the watermarking process is done by embedding singular values of watermark image to the singular values of host image. Moreover, the obtained watermarked images are subjected to different attacks to improve the robustness of the proposed scheme. Finally, the extraction process is based on watermarked image and the reverse method of embedding process to reconstruct the original watermark. The performance is evaluated under various attacks and experimental results show that our algorithm provides a high level of robustness and imperceptibility than the state-of-the-art methods. © 2022 Little Lion Scientific.