On the Design of a Watermarking System: Considerations and Rationales

This paper summarizes considerations and rationales for the design of a watermark detector. In particular, we relate watermark detection to the problem of signal detection in the presence of (structured) noise. The paper builds on the mathematical results from several previously published papers (by our own research group or by others) to verify and support our discussion. In an attempt to unify the theoretical analysis of watermarking schemes, we propose several extensions which clarify the interrelations between the various schemes. New results include the matched filter with whitening, where we consider the effect of the image and watermark spectra and imperfect setting of filter coefficients. The paper reflects our practical experience in developing watermarking systems for DVD copy protection and broadcast monitoring. The aim of this paper is to further develop the insight in the performance of watermark detectors, to discuss appropriate models for their analysis and to provide an intuitive rationale for making design choices for a watermark detector.</p