基于照度优化的自动聚焦技术  

Automatic focusing technique based on illumination optimum

作　　者：孙明磊[1] 宗光华[1] 毕树生[1] 

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100083

出　　处：《光学精密工程》2008年第8期1508-1514,共7页Optics and Precision Engineering

基　　金：国家863高技术研究发展计划资助项目(No.2004AA404260);中国博士后科学基金(No.20070420287)

摘　　要：讨论了照明强度对自动聚焦的影响。开发了照明自动调控系统,为显微视觉照明问题的研究提供了物质前提。利用快速傅里叶变换对离焦图像序列以及不同照明强度图像序列进行频谱分析,证明照明强度条件对图像高频能量影响显著。提出了对图像特征高频能量有效度量的评价函数。自动聚焦实验表明,照明强度对于聚焦曲线的特性产生很大影响,经照度优化后的自动聚焦具有更高的聚焦精度,可达0.857μm,证明照明强度优化对于提高自动聚焦精度具有实用价值。The effect of illumination intensity on automatic focusing in the microscopic vision research field is discussed. An automatic illumination control system is developed to provide experimental conditions for illumination research on microscopic vision. The fast Fourier transform （FFT） is used to analyze spectra of image sequences at defocus and image sequences under different illumination intensities, which proves that illumination intensity conditions impact significantly on the high-frequency energy of images. A evaluating function for the high-frequency energy of images is proposed. The exper- imental results show that illumination intensity has a great impact on focusing curves, and higher ac- curacy of 0. 857μm can be achieved after illumination optimization,which shows that illumination opitimization can improve automatic focusing accuracy.

关 键 词：显微视觉 自动聚焦 照明优化 

分 类 号：TP242.6[自动化与计算机技术—检测技术与自动化装置] TH742.9[自动化与计算机技术—控制科学与工程]