结构光测量自动聚焦系统开发和研究

为配合结构光测量系统来进行更深入的处理和测量，在以PC机为控制核心的基础上设计了一种自动聚焦系统，以实现对不同场景图像的亮度自动调节和精确聚焦功能。系统以Sobel-Tenengrad函数为评价函数，通过登山法搜索极值，在10 s内完成精确聚焦。通过该系统在不同场景下对四种灰度评价函数值进行计算，对其单峰性和鲁棒性进行分析和总结，经过实验后发现Sobel-Tenengrad函数、梯度向量平方函数、拉普拉斯函数综合性能良好，而方差函数未能表现出评价函数应具有的性能。

Research of structured light measurement auto-focus system

In order to help the structured light measurement system for further calculation and measurement,an auto-focus system is designed based on the control of computer.This system can adjust the brightness of the image and complete the auto-focus process in different scenes automatically.Using ＂Sobel-Tenengrad function＂ as criterion function and ＂climbing method＂as focus search strategy,the system precisely focuses in 10 seconds.It can also be used to calculate the function values for four criterion functions in different environments.After analyzing the results,a conclusion is drawn about the unimodality and robustness of these four criterion functions.Sobel-Tenengrad function,squared gradient function and Laplace function perform well in several experiments.However,variance function does not show the properties which criterion function should own.