指紋奇異點是指紋影像的重要特徵，其代表了指紋脊線與谷線的紋理方向特性，因此偵測奇異點位置與數量對於指紋辨識相當重要。傳統的奇異點偵測方法：龐加萊指標易受到局部方向性雜訊影響，因此找到過多參考點，或者漏失真實的參考點。本文提出了一個改善傳統方法的奇異點偵測方法，透過離散小波轉換影像前處理，降低影像雜訊，接著應用蓋柏濾波器強化指紋紋路型態，提高了指紋影像的影像品質，再以龐加萊指標偵測可能的指紋奇異點，以每個可能的奇異點為中心，計算其周圍區域的(LBP)紋理特徵向量，以此篩選參考點，降低誤判率。實驗結果顯示，相對於傳統方法，本方法能夠降低因方向場雜訊而找到的假奇異點的機會，提高指紋奇異點偵測率。

Singularity points are key features in fingerprint images, representing the flow patterns of ridges and valleys. Therefore, the position and quantity of singularities are crucial in fingerprint recognition systems. In conventional singularity detection methods, the Poincaré index is prone to influence by local directional noises. This often results in excessive false reference points or the loss of true reference points. This study proposed an improved singularity detection method through applying a series of processing techniques comprising discrete wavelet transform image preprocessing for reducing image noise, Gabor filtering for strengthening the fingerprint patterns and enhancing fingerprint images, and Poincaré indexing for detecting possible singularities. In the detection process, local binary patterns surrounding every possible singularity were calculated to filter false reference points and reduce error judgments. The experimental results show that, in contrast to conventional methods, this method effectively reduced the number of false singularities caused by directional noise, thereby enhancing the detection rate of the fingerprint singularities.

[1] Anil K. Jain, "An Introduction to Biometric Recognition," IEEE Transactions on Circuits and Systems for Video Technology , vol.14, pp. 4-20, Jan 2004.
[2] 王靜音,"生物辨識技術專利分析",台灣大學圖書資訊學研究所論文
, pp. 80-83, Jan 2007.
[3] Jan Evangelista Purkyně, " Commentatio de examine physiologico organi visus et systematis cutanei" ,1823
[4] Henry C Lee, R E.Gaensslen, "Advances Fingerprint Technology," Boca Raton London New York Washington, D.C. ,1994
[5] Ali Ismail Awad, and Kensuke Baba , " Singular Point Detection for Efficient Fingerprint Classification ", International Journal on New Computer Architectures and Their Applications (IJNCAA), pp. 1-7, 2012
[6] Kenneth Nilsson , Josef Bigun, "Localization of corresponding points in fingerprints by complex filtering," School of Information Science, Computer and Electrical Engineering (IDE) Halmstad University, pp. 1-11, 2003.
[7] Vipul Awasthi , Vanchha Awasthi , Krishna Kumar Tiwari, "Finger Print Analysis Using Termination and Bifurcation Minutiae, " International Journal of Emerging Technology and Advanced Engineering, vol. 2, Issue 2, pp.124 -130, February 2012.
[8] V.S. Srinvasan, N.N. Murthy "Detection of singular points in fingerprint images,” Pattern Recognition, vol. 25, No. 2, 1992
[9] Anil K. Jain, Prabhakar S, Hong L, Pankanti S. " Filterbank-Based fingerprint matching, " IEEE Trans. on Image Processing , pp. 846−859, 2000
[10] 王林,戴模, "基於 Gaussian-Hermite 矩的指紋奇異點定位, "School of Computer
Science and Technology, Shandong University , vol.17, no. 2 , pp.242−249 , February
2006.
[11] B.G. Sherlock, D.M. Monro , "A Model for Interpreting Fingerprint Topology, "Pattern Recognition, vol. 26, no. 7 ,pp.1047-1056, 1993.
[12] Anil K. Jain, Prabhakar S, Hong L, " A multichannel approach to fingerprint classification, " IEEE Trans. On Pattern Analysis and Machine Intelligence 21(4)，pp. 1-28 , April 1999.
[13] Jin Bo, Tang Hua Ping, Xu Ming Lan , " Fingerprint Singular Point Detection Algorithm by Poincare Index, " The College of Electrical and Information Engineering Zhejiang Textile And Fashion College , vol. 7 , Issue 12, pp. 1453-1462, December 2008.
[14] 林旭竹, " Minutiae Extraction from Thermal Fingerprint Image"中原大學電子工程學系論文, pp. 6-16 , 2001.
[15] 賴郁仁, "指紋辨識改善之研究",東吳大學資訊科學系論文
, pp. 4-6 , 2008.
[16] Su Fei ,Sun Peng , Wang Bo-tao , Cai An-ni 1, " Fingerprint singular points extraction based on the properties of orientation model , " The Journal of China Universities of Posts and Telecommunications, pp. 98-104 , February 2011.
[17] Byung-Gyu Kim, Han-Ju Kim and Dong-Jo Park, " New Enhancement Algorithm for Fingerprint Images ", Pattern Recognition, Proceedings. 16th International Conference, vol. 3 , pp. 879 - 882 , 2002.
[18] Lin Hong,Yifei Wan, Ami Jain, " Fingerprint Image Enhancement: Algorithm and Performance Evaluation ," Pattern Analysis and Machine Intelligence, IEEE Transactions , vol. 20 , Issue 8 ,pp. 777 - 789, August 1998
[19] A. K. Jain, S. Prabhakar, and L. Hong, "A multichannel approach to fingerprint classification,” IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 21, no. 4, pp. 348-359, Apr. 1999.
[20] I. Emiroglu, M. B. Akhan, "Pre-processing of fingerprint images", Security Technology, Proceedings. Carnahan Conference on Institute of Electrical and Electronics Engineers 29th Annual 1995 International, pp. 147 - 151, Oct 1995.
[21] Zhang Jinhai, "Research on Fingerprint image preprocessing and thinning," Mechanic Automation and Control Engineering (MACE), Conference on 2011 Second International, pp. 7595 - 7598 , July 2011.
[22] Mohammed Sayim Khalil, Dzulkifli Muhammad, Muhammad Khurram Khan, Khaled Alghathbar , "Singular points detection using fingerprint orientation field reliability," International Journal of Physical Sciences , vol. 5(4) , no. 3 , pp. 352-357 , March 1984.
[23] R. M. Stock, C. W. Swonger, "Development and evaluation of a reader of fingerprint minutiae" No. CAL No. XM-2478-X-1:13-17, pp. 13-17 , 1969
[24] Huina L, Yuan Ping , "A novel approach of K-means based fingerprint segmentation algorithm" Instrumentation & Measurement, Sensor Network and Automation (IMSNA), vol. 1 , pp. 218-221 , 2012.
[25] Xudong Jiang , Manhua Liu , Alex Chichung Kot , "Reference Point Detection for Fingerprint Recognition," Pattern Recognition Proceedings of the 17th International , vol. 1 , pp. 540 - 543 , August 2004.
[26] Vutipong Areekul ,Ukrit Watchareeruetai , Sawasd Tantaratana , "Fast Separable Gabor Filter for Fingerprint Enhancement," Kasetsart Signal and Image Processing Laboratory (KSIP Lab), Department of Electrical Engineering, Faculty of Engineering, Kasetsart University, pp. 403 - 409 , 2004.
[27] Dawei Weng, Yilong Yin, Dong Yang , "Singular points detection based on multi-resolution in fingerprint images," School of Computer Science and Technology, Shandong University, pp. 3376 -3388 , 2011.
[28] D. Maltoni, D. Maio, A.K. Jain, S. Prabhakar, "Singularity and Core Detection," Handbook of Fingerprint Recognition Springer New York , pp. 96-99 , 2011.
[29] Liu Wei , "Fingerprint Classification Using Singularities Detection," International Journal of Mathematics and Computers in Simulation, vol. 2 , Issue 2, pp. 158-162 , 2008.
[30] Hartwig Fronthaler, Klaus Kollreider, Josef Bigu, "Local Feature Extraction in Fingerprints by Complex Filtering," Halmstad University, SE-30118, Sweden , pp. 77-84, 2005
[31] Kenneth Nilsson, Josef Bigun, "Localization of corresponding points in fingerprints by complex filtering," School of Information Science, Computer and Electrical Engineering (IDE) Halmstad University , Sweden , pp. 1-11 , 2003.
[32] Wang, L. , Mo Dai, "Extraction of singular points in fingerprints by the distribution of Gaussian-Hermite moment," Distributed Frameworks for Multimedia Applications, 2005. DFMA '05. Conference on First International , pp. 206-209 , 2005.
[33] Weng Dawei, Yin Yilong, Yang Gongping, Qi Xiuyan, "Singular Point Extraction from Fingerprint Based on Gaussian-Hermite Moment and Improved Poincare Index," School of Computer Science and Technology, Shandong University , pp. 1974-1984 , 2008.
[34] W. M. Koo, A. Kot, "Curvature-based singular points detection," Proc.3rd International Conference on Audio- and Video-Based Biometric Person Authentication,
Lecture Notes in Computer Science (LNCS) , vol. 2091 , pp. 229–234 , 2001.
[35] J. Zhou, F. Chen, J. Gu, "A novel algorithm for detecting singular points from fingerprint images," IEEE Transactions on Pattern Analysis and Machine Intelligence , vol. 31, Issue 7, pp.124 -130, May 2009.
[36] L. Hong, Y. Wan, A. K. Jain, " Fingerprint image enhancement: Algorithm and performance evaluation," IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 20, no. 8, pp.777 -789, 1998.
[37] L. Hong, A. K. Jain, S. Pankanti and R. Bolle, " Fingerprint Enhancement," in Proc. of
the 3 𝑟𝑑 IEEE Workshop on Applications of Computer Vision, Sarasota, FL, pp. 202-207, Dec 1996.
[38] T. Ojala, M. Pietikäinen, and D. Harwood, " Performance evaluation of texture measures with classification based on Kullback discrimination of distributions," Proceedings of the 12th IAPR International Conference on Pattern Recognition , vol.1, pp. 582 - 585, 1994.
[39] L. Nanni ,A. Lumini, " Local binary patterns for a hybrid fingerprint matcher," Pattern Recognition, vol. 41, no. 11, pp.3461 -3466, May 2008
[40] L. Nanni ,A. Lumini, " Descriptors for image-based fingerprint matchers, " Expert Systems with Applications, vol. 39, no. 10, pp.12414 -12422, December 2009.
[41] Ahonen,T., " Face recognition based on the appearance of local regions," Proceedings of the 17th International Conference on Pattern Recognition, ICPR 2004, vol. 3, pp.153-156 , August 2004.
[42] D.Zhong , I.Defee ," Performance of similarity measures based on histograms of local image feature vectors," Pattern Recognition Letters , vol.28 ,no.15, pp.2003-2010 , 2007.
[43] R. J. Mayer, "IDEF0 Function Modeling," Air Force Systems Command, 1992.
[44] Yuan Mei, Rongtao Hou , Jin WangAn ,"An Improved Method for Fingerprints Singular Points Detection based on Orientation Field Partition," International Journal of Signal Processing, Image Processing and Pattern Recognition ,Vol.6, No.1, pp.225-233 , February 2013
[45] TAN Tai-Zhe, NING Xin-Bao, YIN Yi-Long, ZHAN Xiao-Si, CHEN Yun ," A Method for Singularity Detection in Fingerprint Images," Journal of Software., Vol. 14, No. 6, pp.1082-1088 , 2003.