In this paper, we define content-identifier (ContentID) to represent the characteristics of shot. The ContentID carries both positional and temporal color information. Based on the concept of ContentID, we propose a video retrieval method. The method is robust to compression, format conversion, frame dropping and noise such as watermark and so on. Furthermore, based on our retrieval method, we implemented a copyright protection system for digital video using spread-spectrum based watermarking technique.

This letter presents an image rectification scheme that can be used by any image watermarking algorithms to provide robustness against rotation, scaling and translation (RST) transformations.

In this paper, we present a clean and simple formulation of survey propagation (SP) for constraint-satisfaction problems as "probabilistic token passing". The result shows the importance of extending variable alphabets to their power sets in designing SP algorithms.