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: Optimal Detector for Multiplicative Watermarks Embedded in the DFT Domain of Non-White Signals | EURASIP Journal on Applied Signal Processing 2004 16 2522-2532 2004 Hindawi Publishing Corporation Optimal Detector for Multiplicative Watermarks Embedded in the DFT Domain of Non-White Signals Vassilios Solachidis Department of Informatics University of Thessaloniki 54124 Thessaloniki Greece Email vasilis@ Ioannis Pitas Department of Informatics University of Thessaloniki 54124 Thessaloniki Greece Email pitas@ Received 28 September 2003 Revised 10 June 2004 This paper deals with the statistical analysis of the behavior of a blind robust watermarking system based on pseudorandom signals embedded in the magnitude of the Fourier transform of the host data. The host data that the watermark is embedded into is one-dimensional and non-white following a specific probability model. The analysis performed involves theoretical evaluation of the statistics of the Fourier coefficients and the design of an optimal detector for multiplicative watermark embedding. Finally experimental results are presented in order to show the performance of the proposed detector versus that of the correlator detector. Keywords and phrases Fourier transform watermarking detector signal processing. 1. INTRODUCTION The risk of illegal copying reproduction and distribution of copyrighted multimedia material is becoming more threatening with the all-digital evolving solutions adopted by content providers system designers and users. Thus copyright watermark protection of digital data is an essential requirement for multimedia distribution. Robust watermarks can offer a copyright protection mechanism for digital media. The watermark is a signal that contains information about the copyright owner and it is embedded permanently in the multimedia data. It introduces imperceptible content changes that can be detected by a detection program. Robustness is a very important property of the watermarking scheme. The watermarks must be robust to distortions such as those caused .
