Robust Image Watermarking Scheme Based on Subsampling

In this paper, a robust watermarking scheme is presented for digital images copyright protection. The image is firstly subsampled intofour images, and then the randomly generated watermark sequence is embedded into the DFT domain of the four subsampled images respectively. The method takes advantage of the similarity among those subsampled images, and the robustness is greatly improved than traditional spread spectrum watermarking scheme. Experimental results support the conclusions well.