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重庆大学 光电技术及系统教育部重点实验室 重庆,400030
收稿日期:2011-03-01,
修回日期:2011-04-02,
网络出版日期:2011-10-27,
纸质出版日期:2011-10-25
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罗钧, 孙力, 闵志盛. 变焦跟踪曲线在对焦中的应用[J]. 光学精密工程, 2011,19(10): 2326-2332
LUO Jun, SUN Li, MIN Zhi-sheng . Application of zoom tracking curves in focusing[J]. Editorial Office of Optics and Precision Engineering, 2011,19(10): 2326-2332
罗钧, 孙力, 闵志盛. 变焦跟踪曲线在对焦中的应用[J]. 光学精密工程, 2011,19(10): 2326-2332 DOI: 10.3788/OPE.20111910.2326.
LUO Jun, SUN Li, MIN Zhi-sheng . Application of zoom tracking curves in focusing[J]. Editorial Office of Optics and Precision Engineering, 2011,19(10): 2326-2332 DOI: 10.3788/OPE.20111910.2326.
在变焦成像系统中
及时准确地获取跟踪曲线是变焦跟踪的关键
因此
本文提出了一种计算变焦跟踪曲线的策略。首先
采用基于RAW格式图像的梯度算子计算实时图像清晰度;然后
拟合记录的变焦电机和对焦电机的位置关系
得到远物距端和近物距端的两条跟踪曲线
构成变焦跟踪曲线的上下边界;最后
结合几何法和自适应法
应用获取的变焦跟踪曲线上下边界
计算得到系统所处物距下的跟踪曲线。在自主开发的变焦成像系统中采用梯度算子获取了变焦曲线的上下边界
并通过上述策略实现了变焦跟踪
得到了变焦过程中的图像。实验结果表明
使用所述算法的变焦成像系统其图像清晰度比只用自动对焦算法提高了30%以上;将变焦跟踪曲线应用在对焦中
能够提高变焦过程的图像对焦质量。
It is most critical to acquire exact trace curves in time for realizing the zoom tracking in zoom imaging systems. Therefore
a novel computation strategy for zoom tracking curves is proposed. First
a real-time in-focus point is computed by using an image sharpness evaluation operator based on RAW format. Then
the position relations between zoom motor and focus motor are fitted to acquire the two trace curves at the near end and far end of object distances
which are regarded as the upper and lower bounds of trace curves. Finally
both geometric and adaptive zoom tracking methods are combined to be a hybrid algorithm to acquire the curves at some object distances by the method of interpolation. The trace curves for upper and lower bounds are obtained by a gradient operator on a self-developed zoom imaging system
zoom tracking is implemented with acquired trace curves and the image during zoom tracing is acquired. The obtained results show that the image quality of imaging system using proposed approach is improved by 30% as compared with that of the traditional system.It demonstrates that zoom tracking curves can be applied in focusing
and the image quality is improved dur- ing zoom tracing.
参考文献:[1] 李国宁, 刘妍妍, 金龙旭. 用于动态目标跟踪的面阵CCD成像系统[J]. 光学精密工程, 2008, 16(03): 558-564. LI G N; LIU Y Y; JIN L X. Area CCD imaging system used in moving target tracking[J]. Optics and Precision Engineering, 2008, 16(03): 558-564. (in Chinese).[2] 崔继承. 大口径折反射式变焦距物镜的设计[J]. 光学精密工程, 2008, 16(11): 2087-2091. CUI J C. Design of large aperture refractive-reflective zoom lens[J]. Optics and Precision Engineering, 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[C]. Proceedings of the SPIE Electronic Imaging Symposium, 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] 孙明磊, 宗光华, 毕树生. 基于照度优化的自动聚焦技术[J]. 光学精密工程, 2008, 16(08): 1508-1514. SUN M L, ZONG G H, BI S S. Automatic focusing technique based on illumination optimum[J]. Optics and Precision Engineering, 2008, 16(08): 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.-J O. 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 Trans on Consumer Electronics, 2001, 47(3): 694-699.[9] Lee JH, K.S. Kim BDN. Implementation of a Passive Automatic Focusing Algorithm for Digital Still Camera[J]. IEEE Trans 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] 王任华, 沈忙作. 自动对焦算法研究[J]. 光电工程, 2000, 27(4): 11-13.Wang R H, Shen M Z. Research on auto-focus algorithm[J]. Photo-electric engineer, 2000, 27(4): 11-13. (in Chinese). [12] 王倩, 宋恩民, 许向阳, 等. 基于加权邻域相关性的显微镜自动聚焦函数[J]. 光学精密工程, 2008, 16(01): 166-171. WANG Q , SONG E M, XU X Y, et al.. Auto-focusing function for microscope image based on weighted neighborhood correlation[J]. Optics and Precision Engineering, 2008, 16(01): 166-171. (in Chinese).[13] 李奇, 冯华君. 数字图像清晰度评价函数研究[J]. 光子学报, 2002, 31(6): 736-738. 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] 李奇, 冯华君, 徐之海. 自动对焦系统中图像非均匀采样的实验研究[J]. 光子学报, 2003, 32(12): 1499-1501.Li Q, Feng H J, Xu Z 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 Trans an 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.
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