[1] LI G N, LIU Y Y, JIN L X. Area CCD imaging system used in moving target tracking［J］. Opt. Precision Eng., 2008, 16(03): 558-564. (in Chinese).

[2] CUI J CH. Design of large aperture refractive-reflective zoom lens［J］. Opt. Precision Eng., 2008, 16(11): 2087-2091. (in Chinese)

[3] PEDDIGARI V, KEHTARNAVAZ N, LEE SY, et al.. Real-time implementation of zoom tracking on TI DM processor［J］. SPIE, 2005, 5671: 8-18.

[4] KIM Y, LEE J S, MORALES AW. A video camera system with enhanced zoom tracking and auto white balance［J］. IEEE Transactions on Consumer Electronics, 2002, 48(3): 428-434.

[5] SUN M L, ZONG G H, BI SH SH. Automatic focusing technique based on illumination optimum［J］. Opt. Precision Eng., 2008, 16(8): 1508-1514. (in Chinese)

[6] SOHN S M, YANG S H, KIM S W, et al.. SoC design of an auto-focus driving image signal processor for mobile camera applications［J］. IEEE Transactions on Consumer Electronics, 2006, 52(1): 10-16.

[7] KEHTARNAVAZ N H. Development and real-time implementation of a rule-based auto-focus algorithm［J］. Real-Time Imaging, 2003, 9(3): 197-203.

[8] LEE J S, JUNG Y Y, KIM B S, et al.. An advanced video camera system with robust AF, AE, and AWB control［J］. IEEE Transactions on Consumer Electronics, 2001, 47(3): 694-699.

[9] LEE J H, KIMBDN K S. Implementation of a passive automatic focusing algorithm for digital still camera［J］. IEEE Transactions on Consumer Electronics, 1995, 41(3): 449-454.

[10] CHEN C M, HONG C M, CHUANG H C. Efficient auto-focus algorithm utilizing discrete difference equation prediction model for digital still cameras［J］. IEEE Transactions on Consumer Electronics, 2006, 52(4): 1135-1143.

[11] WANG R H, SHEN M Z. Research on auto-focus algorithm［J］. Photo-electric Engineer, 2000,27(4): 11-13. (in Chinese).

[12] WANG Q , SONG E M, XU X Y, et al.. Auto-focusing function for microscope image based on weighted neighborhood correlation［J］. Opt. Precision Eng., 2008, 16(01): 166-171. (in Chinese).

[13] LI Q, FENG H J. Research on digital image definition evaluate function［J］. Optic Letter, 2002,31(6): 736-738. (in Chinese)

[14] WEERASINGHE C, NILSSON M, LICHMAN S, et al.. Digital zoom camera with image sharpening and suppression［J］. IEEE Transactions on Consumer Electronics, 2004, 50(3): 777-786.

[15] LI Q, FENG H J, XU ZH H. Experiment research on unsymmetrical sampling on the auto-focus system［J］. Optic Letter, 2003, 32(12): 1499-1501. (in Chinese)

[16] HE J, ZHOU R, HONG Z. Modified fast climbing search auto-focus algorithm with adaptive step size searching technique for digital camera［J］. IEEE Transactions on Consumer Electronics, 2003, 49(5): 257-262.

[17] CHEN C M, LEE H M. An efficient gradient forecasting search method utilizing the discrete difference equation prediction model［J］. Applied Intelligence, 2002, 16(1): 43-58.