A robust watermarking and image authentication technique

In the past several years, there has been an explosive growth in digital imaging technology and applications. Since digital images and video are now widely distributed via the Internet and various public channels, there is an urgent need for copyright protection against unauthorized data reproduction. Digital watermarking is an effective and popular technique for discouraging illegal copying and distribution of copyrighted digital image information. Furthermore, it can also provide an alternative solution for image authentication. A robust watermarking and image authentication technique is proposed. The proposed scheme includes two parts. The first is a robust watermarking scheme performed in the frequency domain, which can be used to prove the ownership. The second is a standard signature process, which can be used to prove the integrity of the image. The input of the signature process is the edge properties extracted from the image. The signature can be correctly verified when the image is incidentally damaged such as lossy compression.