Information retrieval in digital watermarking

Digital watermarking, the art of robust information hiding in images, has g ained a large interest in both research and industry in the past few years. Every watermarking system has two main parts: watermark embedding and wate rmark extraction/detection. Recent developments in the theoretical analysis of digital watermarking schemes have shown that there is a direct link bet ween digital watermarking and communication theory. These parallels are ext remely helpful when it comes to designing efficient and optimal watermark d etectors. In this article we will focus on this issue and investigate how t o design good watermark detectors taking into account the basics of communi cation theory. Furthermore, we will talk about different ways to achieve ro bustness to geometrical attacks and elaborate on watermark attacks.