基于照度优化的自动聚焦技术研究

本文讨论了显微视觉研究中照明强度对自动聚焦的影响问题。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。首先，利用快速傅立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；然后，提出了对图像特征高频能量有效度量的评价函数；最后通过自动聚焦实验，证明照明强度对于聚焦曲线的特性产生很大影响，同时，经照度优化后的自动聚焦具有更高的聚焦精度。

Research on automatic focusing techniques based on illumination optimum

This paper discusses the opinion that illuminating intensity will seriously affect the effectiveness of automatic focusing techniques in the microscopic vision research field. An automatic lighting control system is developed to provide experimental conditions in illumination research. Firstly, a tool of Fast Fourier Transform (FFT) is used to analyze spectrum of a sequence defocused images and a sequence images under different lighting intensity, proving that lighting intensity conditions impact significantly on the high frequency energy of images. Then, a function that can evaluate high-frequency energy of images is proposed. Finally, some auto-focusing experiments are executed. Experimental results show that lighting intensity has a great impact on focusing curves, and higher accuracy can be achieved after illumination optimization than usual method.