利用强度调制消除零频的傅里叶变换轮廓测量

采用双色正弦条纹投影的傅里叶变换轮廓术中零频分量的扩展对有用基频分量有影响,为此提出一种新型的基于强度调制的零频消除方法提高测量准确度和范围.通过采集一帧变形彩色条纹图并分离颜色通道获得两幅相位差为π的条纹图,对变形条纹做强度调制校正,进而消除零频分量,实现高度解析.理论模拟和实验测试均验证了此方法的有效性.相比传统的相移消除零频分量的方法,此方法具有显著的速度优势,适合于三维物体的实时测量.

Fourier Transform Profilometry Using Zero Frequency Elimination Based on Gray Modulation

The bi-color sinusoidal fringe patterns are used to depress the effect of zero frequency extension on fundamental frequency component in Fourier transform profilometry.A novel intensity-modulated method is proposed to eliminate the zero frequency component,which can improve the measuring precision and range.Two compounding monochrome fringe patterns with phase difference of π can be obtained by separating color channel of one color image.After calibration of intensity modulation and zero component elimination,the shape is obtained.The feasibility of the algorithm is validated by both theoretical simulation and experiment performance.Compared to the traditional phase shift method to eliminate the zero frequency component,this method has a significant advantage at speed and is suitable for real-time measurement of three-dimensional objects.