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Improved watermark detection robust to camcorder capture based on quadrangle estimation

In this paper, we propose a blind watermark detection scheme which is robust against composite geometric distortions. The composite geometric distortions mean that an image or a video is rotated, perspective-projected, and resized at the same time. It commonly happens during capturing a movie in a theater by a camcorder illegally. Local auto-correlation function (LACF) with a novel estimation model is utilized for calculating composite geometric distortions. We demonstrate robustness of the presented scheme against composite geometric distortions for digital cinema.