Robust image watermarking on the DCT domain

This paper proposes two simple DCT-domain-based schemes to embed single or multiple watermarks into an image for copyright protection and data monitoring and tracking. The watermark data are essentially embedded in the middle band of the DCT domain to make a tradeoff between visual degradation and robustness. The proposed schemes are simple and no original host image is required for watermark extraction. The algorithm also features the capability of embedding multiple orthogonal watermarks into an image simultaneously. A set of systematic experiments, including Gaussian smoothing, JPEG compression, and image cropping are performed to prove the robustness of our algorithms.