[1] CHEN Guojin. Study on the autofocusing technology of digital image and realization for an autofocusing system[D]. Xi′an: Xidian University, 2007: 10-12.
[2] LI Qi, FENG Huajun, XU Zhihai. Autofocus apparatus with digital signal processor[C]. SPIE, 2005, 5633: 416-423.
[5] NI Jun, WEI Min, YUAN Jiahu, et al. Efficient autofocus algorithm for optical measurement system[C]. SPIE, 2009, 7283: 728344.
[8] WANG Chao, JIANG Yuanda, ZHAI Guangjie, et al. Study on auto focusing algorithm for microscope base on digital image processing[J]. Chinese Journal of Scientific Instrument, 2009, 30(6): 1290-1294.
[9] LIANG Minhua, WU Zhiyong, CHEN Tao. Autofocusing adjustment of theodolites by largest gradient method[J]. Optics and Precision Engineering, 2009, 17(12): 3016-3021.
[11] GOODMAN J W. Introduction to fourier optics [M]. QIN Kecheng, LIU Peisen, CHEN Jiabi, et al. transl, 3rd ed. Beijing: Publishing House of Electronics Industry Press. 2006, 9: 114-116.