[1] [1] K. R. Spring, M. W. Davidson. Depth of Field and Depth of Focus [DL]. http://www.microscopyu.com/ 2010

[2] [2] R. A. Jarvis. Focus optimization criteria for computer image processing ［J］. Microscope, 1976, 24(2): 163～180

[3] [3] J. M. Tenenbaum. Accommodation in Computer Vision ［D］. USA: Stanford University, 1970

[4] [4] G. J. Chen, M. F. Zhu, Y. K. Wang et al.. Study on definition evaluation function based on image contrast variation［C］. In: Proc the 2007 Annual Conference on International Conference on Computer Engineering and Applications, Australia, 2007,254～258

[5] [5] FC. A. Groen, Young I, G. Lightart. A comparison of different focus functions for use in autofocus algorithms [J]. Cytometry, 1985, 6(2): 81～91

[6] [6] Chen Lu, Xu Wendong, Zhu Qing. A novel focus servo module in hybrid magneto-optical recording testing system［J］. Acta Optica Sinica, 2009, 29(5): 1341～1346

[7] [7] Fan Fuming, Cheng Lianglun, Wang Xiaofen et al.. A new type of high-speed automatic focusing system［J］. Opto-Electronic Engineering, 2010, 37(5): 127～132

[8] [8] Qu Yufu, Pu Zhaobang, Zhao Huijie et al.. Influence factor analysis of sensitivity of focus criteria function ［J ］. Acta Optica Sinica, 2005, 25(7): 902～906

[9] [9] Gao Chao, Zhu Hongjun, Guo Yongcai et al.. A focusing criterion function based on edge point counting［J］. Chinese J. Lasers, 2009, 36(s2): 163～167

[10] [10] Hu Fengping, Chang Yilin, Ma Yanzhuo et al.. Development of the video automatic focus method［J］. Acta Photonica Sinica, 2010, 39(10): 1901～1906

[11] [11] A. Santos, C. O. Solorzano, J. J. Vaquero et al.. Evaluation of autofocus functions in molecular cytogenetic analysis ［J］. J. Microscopy, 1997, 188(3): 264～272

[12] [12] Y. Sun, S. Duthaler, B. J. Nelson. Autofocusing algorithm selection in computer microscopy［C］. In: Proc Intelligent Robots and Systems, 2005 (IROS 2005) Aug 2-6, 2005: 70～76

[13] [13] J. M. Russell, T. S. Douglas. Evaluation of autofocus algorithms for tuberculosis microscopy［C］. In: Proc 29th Annual International Conference of the IEEE EMBS Cité Internationale Lyon, France, August 23-26, 2007: 3489～3492

[14] [14] B. S. Luthi, N. Thomas, S. F. Hwiid et al.. An efficient autofocus algorithm for a visible microscope on a Mars lander ［J］. Planetary and Space Science, 2010, 58(10): 1258～1264

[15] [15] S. K. Nayar, Y. Nakagawa. Shape from focus ［J］. IEEE Transactions on Pattern Analysis and Machine Intelligence, 1994, 16(8): 824～831

[16] [16] J. F. Brenner, B. S. Dew, J. B. Horton et al.. An automated microscope for cytological research: a preliminary evaluation ［J］. J. Histochemistry and Cytochemistry, 1976, 24(1): 100～111

[17] [17] D. Vollath. Automatic focusing by correlative methods ［J］. J. Microscopy, 1987, 147(3): 279～288

[18] [18] J. Sun, Y. H. Yuan, C. Y. Wang. Comparison and analysis of algorithms for digital image processing in autofocusing criterion［J］. Acta Optica Sinica, 2007, 27(1): 35～39