A DCT-based robust image watermarking using local moment

In order to protect the intellectual property right of an image, this paper proposes a robust digital watermarking technology based on discrete cosine transform (DCT). It mainly uses the local average moment to modify specific AC values of each DCT block so as to embed the watermark. When the content of a digital image is modified or even possessed by others through the Internet, the creator can prove the ownership of this image by the hidden watermark. Experimental results show that the proposed scheme maintains a satisfactory image quality, and the extracted watermark can also have a good accuracy after various attacks, with which the ownership of the image can be still identified.