Semi-blind automatic temporal registration for video watermarking systems

Despite the academic focus on blind detection, many forensic watermarking systems actually operate in a non-blind fashion to accommodate for real-life desynchronization attacks. In other words, the original content is needed to perform watermark detection e.g. to re-align the pirate sample with the original content prior to watermark decoding. A somehow intermediate strategy, that could be coined `semi-blind´, only requires access to a condensed representation of the original content i.e. content fingerprints. In this paper, we combined a variant of the dynamic time warping algorithm together with multi-dimensional temporal fingerprints to realign pirate video samples. Reported experimental results clearly demonstrate improved accuracy compared to state-of-the-art registration methods for a number of synthetic and real-life attack scenarios.