1. N. Ahmed, T. Natarajan and K. Rao, Discrete cosine transform, IEEE Transactions on Computers, vol. 23(1), pp. 90–93, 1974.
2. Y. Akao, K. Kobayashi and Y. Seki, Examination of spur marks found on inkjet-printed documents, Journal of Forensic Science, vol. 50(4), pp. 915–923, 2005.
3. H. Baird, The state of the art of document image degradation modeling, Proceedings of the Fourth International Association for Pattern Recognition Workshop on Document Analysis Systems, pp. 1–16, 2000.
4. C. Chang and C. Lin, LIBSVM: A Library for Support Vector Machines, Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan (www.csie .ntu.edu.tw/~cjlin/libsvm).
5. J. Chim, C. Li, N. Poon and S. Leung, Examination of counterfeit banknotes printed by all-in-one color inkjet printers, Journal of the American Society of Questioned Document Examiners, vol. 7(2), pp. 69–75, 2004.