An Approximate Schur Decomposition-Based Spatial Domain Color Image Watermarking Method

In this paper, an approximate Schur decomposition-based spatial domain blind color image watermarking method is proposed to protect the copyright of color images, which has low computation complexity similiar to the watermarking technique in the spatial domain and strong robustness similiar to the watermarking technique in the transform domain. First, the approximate maximum eigenvalue of Schur decomposition is calculated in the spatial domain by the proposed method. Second, the approximate maximum eigenvalue is used to embed and extract the color watermark image in the spatial domain without the true Schur decomposition. Moreover, the procedures of the proposed watermarking method are given in detail. The proposed technique is performed on the spatial domain based on the approximate Schur decomposition and belongs to blind watermarking technique. The experimental results on two publicly available image databases (CVG-UGR and USC-SIPI) have demonstrated the effectiveness of the proposed method in terms of invisibility, robustness, and the real-time feature.