Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Stochastic Image Warping for Improved Watermark Desynchronization | Hindawi Publishing Corporation EURASIP Journal on Information Security Volume 2008 Article ID 345184 14 pages doi 2008 345184 Research Article Stochastic Image Warping for Improved Watermark Desynchronization Angela D Angelo 1 Mauro Barni 1 and Neri Merhav2 1 Department of Information Engineering University of Siena 53100 Siena Italy 2 Department of Electrical Engineering Technion-Israel Institute of Technology 32000 Haifa Israel Correspondence should be addressed to Angela D Angelo Received 28 November 2007 Accepted 19 March 2008 Recommended by Deepa Kundur The use of digital watermarking in real applications is impeded by the weakness of current available algorithms against signal processing manipulations leading to the desynchronization of the watermark embedder and detector. For this reason the problem of watermarking under geometric attacks has received considerable attention throughout recent years. Despite their importance only few classes of geometric attacks are considered in the literature most of which consist of global geometric attacks. The random bending attack contained in the Stirmark benchmark software is the most popular example of a local geometric transformation. In this paper we introduce two new classes of local desynchronization attacks DAs . The effectiveness of the new classes of DAs is evaluated from different perspectives including perceptual intrusiveness and desynchronization efficacy. This can be seen as an initial effort towards the characterization of the whole class of perceptually admissible DAs a necessary step for the theoretical analysis of the ultimate performance reachable in the presence of watermark desynchronization and for the development of a new class of watermarking algorithms that can efficiently cope with them. Copyright 2008 Angela D Angelo et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and .
