Vassilios Solachidis

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A method for watermarking of polygonal lines is proposed in this paper. The watermark is embedded in the Fourier descriptors of the polygonal line causing minor distortions to the coordinates of the vertices of the polygonal line. Watermarks generated by this technique can be successfully detected even after rotation, translation , scaling and reflection of(More)
In this paper, a method for digital image watermarking is described that is resistant to geometric transformations. A private key, which allows a very large number of watermarks, determines the watermark, which is embedded on a ring in the DFT domain. The watermark possesses circular symmetry. Correlation is used for watermark detection. The original image(More)
In this paper, a robust blind watermarking method for 3D volumes is presented. A bivalued watermark is embedded in the Fourier transform magnitude of the 3D volume. The Fourier domain has been selected because of its important properties in terms of scaling and rotation invariance. Furthermore, a special symmetry of the watermark is exploited, in order to(More)
In this paper a benchmarking system for watermarking algorithms is described. The proposed benchmarking system can be used to evaluate the performance of watermarking methods used for copyright protection, authentication, fingerprinting, etc. Although the system described in the paper is used for image wa-termarking, the general framework can be used, by(More)
A thorough investigation on all possible scenarios where digital imperceptible watermarking is applicable is presented in this paper. All previously proposed watermarking schemes fall to at least one of the referenced application categories. Possible attacks are divided into categories and application scenarios are presented, always referring to the(More)
In this paper, statistical analysis of watermarking schemes based on correlation detection is presented. Statistical properties of watermark sequences generated by piecewise-linear Markov maps are exploited, resulting in superior watermark detection reliability. Correlation/spectral properties of such sequences are easily controllable, a fact that reflects(More)
In this paper, theoretical performance analysis of watermarking schemes based on correlation detection is undertaken, leading to a number of important observations on the watermarking system detection performance. Statistical properties of watermark sequences generated by piecewise-linear Markov maps are investigated. Correlation/spectral properties of such(More)
This paper proposes a complete framework for accurate face localization on video frames. Detection and forward tracking are first combined according to predefined rules to get a first set of face candidates. Backward tracking is then applied to provide another set of possible localizations. Finally a dynamic programming algorithm is used to select the(More)