[1] LIU D X, SUN F ZH, HUANG X L. Method of computer-aided selection for the aviation precision coupling assembly [J]. Machinery, 2010, 32(6): 80-82. (in Chinese).

[2] ALLEGRO S, CHANEL C, JACOT J. Autofocus for automated microassembly under a microscope [J]. Image Processing, 1996(2): 677-680.

[3] SUN L N, CHEN L G, LIU P K, et al.. Some issues on the micro-vision system for a micromanipulation robot [J]. Opt. Precision Eng., 2002, 10(2):171-175. (in Chinese)

[4] DUAN R L, DUAN H B, LI Q X, et al.. Micro-assembly autofocusing system based on image processing [J]. Opt. Precision Eng., 2006, 14(3):468-472. (in Chinese)

[5] WANG Y W, LIU X L, XIE H . A wavelet based focus measure and 3D autofocusing for microscope images [J]. Opt. Precision Eng., 2006, 14(6):1063-1069.(in Chinese)

[6] LIU X Y, WANG W H , SUN Y. Autofocusing for automated microscopic evaluation of blood smear and pap smear [J]. Engineering in Medicine and Biology Society, 2006， 4718-4721.

[7] CHEN L G, WANG M Y, YANG ZH L, et al..Fast autofocus method for microscopic computer vision [J]. Opt. Precision Eng., 2010, 18(6):1361-1366. (in Chinese)