A novel DCT-based approach for secure color image watermarking

In this paper, focusing on visually meaningful color image watermarks, we construct a new digital watermarking scheme based on the Discrete Cosine transformation. The proposed method uses the sensitivity of human eyes to adaptively embed a watermark in a color image. In addition, to prevent tampering or unauthorized access, a new watermark permutation function is proposed, which causes a structural noise over the extracted watermark. Also, we have proposed a procedure to eliminate this noise to decrease false positives and false negatives in the extracted watermark. The experimental results show that embedding the color watermark adapted to the original image produces the most imperceptible and the most robust watermarked image under geometric and valumetric attacks.