An algorithm of digital watermarking with robust for image cropping

Digital watermarking algorithms in the frequency domain have many good characteristics. However, these algorithms do not have the robustness for geometric attacks such as cropping, because the positions where the watermarks are embedded must be known before detecting and extracting the watermark in these methods. The paper solves this problem by proposing a new image watermarking algorithm for embedding watermarks in the DCT domain. It is based on some new techniques, such as labeling the watermark's position and image patching. Experimental results show that the proposed algorithm is very effective.