高精度的数字光投影傅里叶变换轮廓术  

Higher-precision FTP based on digital light projecting

作　　者：许平[1] 陈文静[1] 苏显渝[1] 

机构地区：[1]四川大学光电科学技术系,四川成都610064

出　　处：《光电工程》2005年第11期59-62,共4页Opto-Electronic Engineering

基　　金：国家自然科学基金(10376018)资助项目

摘　　要：傅里叶变换轮廓术(FTP)采用数字光投影仪(DLP),可以得到各种结构光场,提高了测量的灵活性。由于DLP伽马非线性的存在,变形条纹中会出现高次谐波,可能导致频谱混叠,带来测量误差。因此利用一种基于条纹图强度统计分析的方法,求出DLP的伽马值并反馈给DLP,使其投影出有良好正弦性的结构条纹,能抑制变形条纹中高次谐波的出现,保证FTP的测量精度。将采用和不采用伽马校正的两种情况作对比实验,证明前者测量结果优于后者。Digital Light Projector（DLP）is used as a Profilometry（FTP）, which brings great flexibility. However, projecting device in Fourier Transform the gamma nonlinearity of DLP introduces specific higher-order harmonics, which perhaps leads to appearance of spectrum aliasing, and error of measurement. A gamma-correction method was proposed based on statistical analysis of fringe pattern＇s intensity to calculate the gamma value of DLP, and fed back to DLP to project the gamma-corrected fringe pattern onto the object. The fringe pattern captured by CCD has no high order frequency, so that the accuracy of measurement can be ensured. Experimental results demonstrate that measurement with gamma-correction is better than that without gamma-correction.

关 键 词：傅里叶变换轮廓术(FTP) 数字光投影仪 伽马校正 频谱混叠 

分 类 号：TN247[电子电信—物理电子学]