【摘要】 傅里叶变换轮廓术(FTP)技术通过计算傅里叶变换、在空间频域中滤波和逆傅里叶变换来解析被测对象轮廓数据,实现将相位信息转换为被测对象的高度。FTP重建三维曲面时,用来提取基频成分的带通滤波算法对测量精度有很大影响,该技术的关键问题是无法精确提取到一阶频谱尤其是在频域比较复杂的情况下,传统滤波算法在FTP滤波过程中已被证明是不够准确的。因此提出一种双椭圆滤波算法的傅立叶变换轮廓术,双椭圆滤波算法能更好的滤出携带有物体高度信息的一阶频谱,结合光栅投影技术能更有效提高被测物体梯度限制和减少误差,实验结果表明该双椭圆滤波算法优于其它现有的FTP滤波技术。更多还原

【Abstract】 The object shape is decoded by calculating the Fourier transform, filtering in the spatial frequency domain, and calculating the inverse Fourier transform; afterward, a conversion of the measured phase to object height is carried out. In the Fourier transforms profilometry(FTP), the band-pass filter that extracts the fundamental frequency component has a significant influence on the reconstructed accuracy of the 3 D profile. However, a challenging problem commonly encountered by FTP using fringe projection is its unreliable extrac-tion of precise spectral information from the spectral domain especially when the spectral domain is complicated to process. The traditional filtering methods have been proved unsuccessful in FTP. Wherefore this article presents the double elliptic filter algorithm for FTP, the new innovative filtering algorithm is proposed to better filter out the carrier frequency signal carrying the object height information in this paper. The double elliptical filtering is developed and optimized to reconstruct 3-D surface models with improved measurement accuracy. Some experimental results shows that the accuracy can be effectively enhanced and the error reduced by using the double elliptical filtering algorithm, and the algorithm is superior to other existing FTP filtering methods.更多还原