基于双色条纹投影的快速傅里叶变换轮廓术

在实际傅里叶变换轮廓术测量中，获取的条纹图扩展的零频分量对傅里叶变换轮廓术的测量精度和测量范围有很大影响，甚至妨碍正确三维面形的恢复。π相移技术常被用来消除零频分量对测量的影响，但需要在测量系统中安装精密相移装置，并需要采集两帧具有π相位差的条纹图。传统傅里叶变换轮廓术中，完成精密相移需要较长的时间，影响了傅里叶变换轮廓术测量方法的实时性。提出了采用双色正弦光栅投影来实现从一帧条纹图中消除零频对傅里叶变换轮廓术测量的影响。该方法同传统的π相移方法相比，不需要相移装置，测量系统简单，并且能真正实现高速测量。

Improved FTP Based on Bi-Color Fringe Projection

In Fourier transform profilometry (FTP), when zero component extends to fundamental component, it will influence measuring range and measuring precision, even makes the correct three-dimensional surface impossible. π phase shifting technique is usually used to eliminate the zero component. But this needs adding phase shifting device in measurement system and capturing two fringe patterns with π phase difference each other. Now a novel method is proposed, in which a bi-color fringe pattern is projected onto the object and the deformed color fringe pattern is captured by color digital camera. Two separate fringe patterns with π phase difference are extracted and used to eliminate the zero component. The method not only can eliminate zero frequency overlapping fundamental component using only one fringe pattern, but also simplify the experimental setup because of no need of phase-shift device.