A variational approach for digital watermarking
We describe a digital watermarking framework by minimizing an appropriate variational problem with an energy/cost function accounting for properties such as robustness, fidelity, and so forth. The process of embedding a watermark into a multimedia data can then be treated as solving an optimization problem, where we show that it can be transformed into finding the minimum cost (integral) flow of a watermarking network. The framework is very general and flexible since the cost function can be easily modified to accommodate other criteria. Unlike other watermarking methods, our approach is implemented via solving a network flow problem, and consequently this protects the watermarking scheme from deliberate attacks designed specifically using the knowledge of the algorithm.