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 Online Signature Verification Using Fourier Descriptors | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 260516 13 pages doi 2009 260516 Research Article Online Signature Verification Using Fourier Descriptors Berrin Yanikoglu1 and Alisher Kholmatov2 1 Faculty of Engineering and Natural Sciences Sabanci University Istanbul 34956 Turkey 2 National Research Institute of Electronics and Cryptology UEKAE Scientific and Technological Research Council of Turkey TUBITAK Gebze Kocaeli 41470 Turkey Correspondence should be addressed to Berrin Yanikoglu berrin@ Received 27 October 2008 Revised 25 March 2009 Accepted 25 July 2009 Recommended by Natalia A. Schmid We present a novel online signature verification system based on the Fast Fourier Transform. The advantage of using the Fourier domain is the ability to compactly represent an online signature using a fixed number of coefficients. The fixed-length representation leads to fast matching algorithms and is essential in certain applications. The challenge on the other hand is to find the right preprocessing steps and matching algorithm for this representation. We report on the effectiveness of the proposed method along with the effects of individual preprocessing and normalization steps based on comprehensive tests over two public signature databases. We also propose to use the pen-up duration information in identifying forgeries. The best results obtained on the SUSIG-Visual subcorpus and the MCYT-100 database are and error rate on skilled forgeries respectively. The fusion of the proposed system with our state-of-the-art Dynamic Time Warping DTW system lowers the error rate of the DTW system by up to about 25 . While the current error rates are higher than state-of-the-art results for these databases as an approach using global features the system possesses many advantages. Considering also the suggested improvements the FFT system shows promise both as a stand-alone system and especially in
