Analysis of watermark detection using SPOMF

An important aspect of almost every watermarking system is the performance of the method by which watermark patterns are correlated with (derived features of) the suspect content. In the JAWS video watermarking system, developed at Philips Research, correlation is realized by symmetrical phase-only matched filtering. SPOMF detection has experimentally been shown to be an excellent correlation method. In this paper we address the problem of building a theoretical understanding of its performance. Being a non-linear correlation method, analysis of SPOMF detection performance is difficult. This paper is a first attempt to tackle the problem of deriving an analytical relationship between the energy of the embedded watermark and the reliability of detection. The theoretical results are compared with experimental results, and are found to be in good agreement.