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 Identification of Sparse Audio Tampering Using Distributed Source Coding and Compressive Sensing Techniques | Hindawi Publishing Corporation EURASIP Journal on Image and Video Processing Volume 2009 Article ID 158982 12 pages doi 2009 158982 Research Article Identification of Sparse Audio Tampering Using Distributed Source Coding and Compressive Sensing Techniques G. Valenzise G. Prandi M. Tagliasacchi and A. Sarti Dipartimento di Elettronica e Informazione Politecnico di Milano Leonardo da Vinci 32 20133 Milano Italy Correspondence should be addressed to G. Valenzise valenzise@ Received 16 May 2008 Revised 30 September 2008 Accepted 20 November 2008 Recommended by Anthony Vetro The increasing development of peer-to-peer networks for delivering and sharing multimedia files poses the problem of how to protect these contents from unauthorized manipulations. In the past few years a large amount of techniques have been proposed to identify whether a multimedia content has been illegally tampered or not. Nevertheless very few efforts have been devoted to identifying which kind of attack has been carried out especially due to the large data required for this task. We propose a novel hashing scheme which exploits the paradigms of compressive sensing and distributed source coding to generate a compact hash signature and apply it to the case of audio content protection. The audio content provider produces a small hash signature by computing a limited number of random projections of a perceptual time-frequency representation of the original audio stream the audio hash is given by the syndrome bits of an LDPC code applied to the projections. At the content user side the hash is decoded using distributed source coding tools. If the tampering is sparsifiable or compressible in some orthonormal basis or redundant dictionary it is possible to identify the time-frequency position of the attack with a hash size as small as 200bits second the bit saving obtained by introducing distributed source coding ranges between 20 to 70 . Copyright 2009 G. Valenzise et al.
