[1] Qiao Naosheng, Ye Yutang, Mo Chunhua et al.. Method for the detection of concentric circles of photoelectric image of circular hole in printed circuit board［J］. Acta Optica Sinica, 2010, 30(1): 75～78

[2] Z. J. Zhang, H. Hu. Measurement of the effective focal length by the centerline detection of light stripes［C］. IEEE RAM, 2010: 398～402

[3] L. L. Li, W. J. Zhang, F. Li. A novel autofocusing approach for real-time through-wall imaging under unknown wall caracteristics［J］. IEEE Transac. Geosci. Remote Sensing, 2010, 48(1): 423～431

[4] Liu Changgeng, Wang Dayong, Zhang Yizhuo et al.. Derivatives-based autofocus algorithms for the digital holographic imaging［J］. Chinese J. Lasers, 2009, 36(11): 2989～2996

[5] Ni Jun, Yuan Jiahu, Wu Qinzhang. Identification for optical image definition based on edge feature［J］. Chinese J. Lasers, 2009, 36(1): 172～176

[6] G. J. Chen, M. F. Zhu, Y. K. Wang et al.. Study on definition evaluation function based on image contrast variation［C］. Proceedings of the 2007 WSEAS International Conference on Computer Engineering and Applications, 2007: 254～258

[7] J. Martinez-Baena, J. Fdez-Valdivia, J.A. Garcia. A multi-channel autofocusing scheme for gray-level shape scale detection［J］. Pattern Recognition, 1997, 30(10): 1769～1786

[8] N. K. C. Nathaniel, A. N. Poo, M.H. Ang Jr. Practical issues in pixel-based autofocusing for machine vision［C］. IEEE International Conference on Robotics and Automation, 2001, 3: 2791～2796

[9] Liu Jun, Zhao Jibing, Liu Weijun et al.. Gene chip microarray fluorescent spots images CCD scanning and acquiring system［J］. Chinese J. Lasers, 2010, 37(2): 505～509

[10] Y. Song, M.T Li. Research on SUSAN based auto-focusing algorithm for optical microscope application［C］. IEEE International Conference on Mechatronics and Automation, 2006: 1237～1241

[11] V. V. Makkapati. Segmentation based microscope autofocusing for blood smears［C］. SPIE, 2009, 7260(3D): 1～8

[12] Vesna. Popovic, Igor. Djurovic, LJubia. Stankovic et al.. Autofocusing of SAR images based on parameters estimated from the PHAF［J］. Signal Processing, 2010, 90(5): 1382～1391

[13] S. Yazdanfar, K. B. Kenny, K. Tasimi et al.. Simple and robust image-based autofocusing for digital microscopy［J］. Opt. Express, 2008, 16(12): 8670～8677

[14] J.M. Geusebroek, F. Cornelissen, A. W. M. Smeulders et al.. Robust autofocusing in microscopy［J］. Cytometry, 2000, 39: 1～9

[15] M. Subbarao, J. K. Tyan. Selecting the optimal focus measure for autofocusing and depth-from-focus［J］. IEEE Transac. Pattern Analys. Mach. Intellig., 1998, 20(8): 864～870

[16] Zong Guanghua, Sun Minglei, Bi Shusheng et al.. Research on autofocus technique in micro-vision［J］. Acta Optica Sinica, 2005, 25(9): 1225～1232

[17] Deng Yunkai, Wang Yu, Yang Xianlin et al.. The research of autofocus optimization algorithm based on contrast optimization criterion［J］. Acta Electronica Sinica, 2006, 34(9): 1742～1744

[18] P. Ge, B. F. Mao, H. J. Feng et al.. Design and optimization for microscope autofocus systems based on the analysis of video signals［C］. SPIE, 2009, 7459(2U): 1～7

[19] L. Q. Xu, Z. Ye, J. P. Wu et al.. Microscope auto-focusing system with the self-adaptive mountain-climbing search method based on PC control［C］. SPIE, 2008, 6834(2E): 1～8

[20] J. He, R. Z. Zhou, Z. L. Hong. Modified fast climbing search auto-focus algorithm with adaptive step size searching technique for digital camera［J］. IEEE Transac. Consum. Electron., 2003, 49(2): 257～262

[21] Sun Junding, Chen Suxia, Guo Qiqiang. Automatic extraction of regions of interest based on rough sets［J］. Transducer and Microsystem Technologies, 2009, 28(3): 101～107

[22] Yu Chao, Wang Boxiong, Zheng Hanqing et al.. Improved TennenGrad function for microscopic coarse autofocuing［J］. Opt. Preci. Engng., 2007, 15(5): 784～790

[23] Vladimir V. Khryashchev, Andrey L. Priorov, Ilya V. Apalkov et al.. Image denoising using adaptive switching median filter［C］. ICIP, 2005, 1: 117～120

[24] Xu Jiahua. Optical Engineering Fundamentals［M］. Beijing: China Machine Press, 1988. 117～121