显微镜自动对焦评价函数新算法

New Auto-focus Evaluation Function algorithm of Microscope

在研究显微镜自动对焦系统的过程中,本文设计了数字滤波评价函数;比较了数字滤波评价函数与几种已有的评价函数的性能;研究了数字滤波器的阶数和截止频率对数字滤波评价函数的影响;改进了数字滤波评价函数的高效性。实验结果表明,数字滤波评价函数具有良好的灵敏度、稳定性和对焦精度;对焦窗口取50*50、数字高通滤波器的阶数为20和截止频率为4.5MHz时,显微镜自动对焦系统完成自动对焦的时间为4.75S,具有良好的实时性。

In the process of researching automatic focusing system of microscope,this paper design digital filtering evaluation function. The performance of digital filtering evaluation function and several kind of evaluation function are compared. The influence of digital high pass filter＇s order and cut-off frequency are researched to the digital filtering evaluation function.The efficiency of digital filtering evaluation function is improved. Experimental result indicated that the digital filtering evaluation function has good sensitivity,stability and focusing precision. When the focusing window is fifty by fifty,the digital high pass filter＇s order is twenty and cut-off frequency is 4.5MHz,the auto-focus system of microscope spends 4.75s to complete the auto-focus,which has a excellent real-times performance.