Abstract: In this paper, having analyzed the essence of the SVD based watermarking algorithms, we propose a novel public watermarking algorithm without SVD. Basically our approach is based on the matrix-norms of sub-images. Compared with the SVD based algorithms, the new algorithm is quite simple and can be easily implemented with a lower computational cost. We give various numerical experiments for the new algorithm with different kinds of norms. The experimental results with three kinds of norms reported in this paper show that this algorithm has a good transparence of the embedded watermark image and is robust to attacks such as re-sampling, smoothing, noise adding, and JPEG-compression.