大曲率表面物体形貌的光学检测方法研究

本文提出了两种用于曲面形貌检测的傅里叶变换法中的频域低通滤波器，并与常用的窗口法低通滤波器进行了比较，给出了实际测量的结果。这两种频域低通滤波器（高幂次指数滤波器和矩形余弦滤波器）有可方便调整且平直的通带，平直无旁瓣的阻带，较陡的边带将通带与阻带间圆滑过渡连接，从而可尽可能多地保留有用频率成分，很好地滤掉直流和不用的高频分量，且较好地抑制振铃现象，克服一般窗口法设计的低通滤波器中旁瓣的影响。具有使用简单、参数调整方便、应用范围广等特点，尤其是对具有大梯度表面和棱角细节的物体检测更有独到之处，具有广泛的应用前景。

Study of Optical Measurement Method of 3 D Surface with Large Curvature

Two digital low pass filter used in Fourier Transform Profilometry is proposed and compared with Window low pass filter,verified by experiments.The two filters(high power index filter and rectangle cosine filter)have a adjustable flat pass band,flat and no sidelobes stopband,and the precipitous transition band links the pass band and the stopband slick and sly.Thus more useful frequency component can be kept as far as possible,the useless high frequency component is filtered quite well.The influence of side peak of low pass filter,designed by common window functions method,can be overcame.Experimental results prove that these two filter are simple in used,convenient in adjusting parameter,and have wide scope of application.There are many special characteristic in measuring the object details with large crook rate changing.