Liu Kai, Wang Yongchang, Lau Daniel L, Hao Qi, Hassebrook Laurence G
Electrical and Computer Engineering, University of Kentucky, Lexington, Kentucky 40506, USA.
J Opt Soc Am A Opt Image Sci Vis. 2010 Mar 1;27(3):553-62. doi: 10.1364/JOSAA.27.000553.
Phase measuring profilometry is a method of structured light illumination whose three-dimensional reconstructions are susceptible to error from nonunitary gamma in the associated optical devices. While the effects of this distortion diminish with an increasing number of employed phase-shifted patterns, gamma distortion may be unavoidable in real-time systems where the number of projected patterns is limited by the presence of target motion. A mathematical model is developed for predicting the effects of nonunitary gamma on phase measuring profilometry, while also introducing an accurate gamma calibration method and two strategies for minimizing gamma's effect on phase determination. These phase correction strategies include phase corrections with and without gamma calibration. With the reduction in noise, for three-step phase measuring profilometry, analysis of the root mean squared error of the corrected phase will show a 60x reduction in phase error when the proposed gamma calibration is performed versus 33x reduction without calibration.
相位测量轮廓术是一种结构光照明方法，其三维重建容易受到相关光学器件中非单位伽马的影响而产生误差。虽然随着所采用的相移图案数量增加，这种畸变的影响会减小，但在实时系统中，由于目标运动的存在限制了投影图案的数量，伽马畸变可能是不可避免的。本文建立了一个数学模型来预测非单位伽马对相位测量轮廓术的影响，同时还介绍了一种精确的伽马校准方法以及两种将伽马对相位确定的影响降至最低的策略。这些相位校正策略包括有伽马校准和无伽马校准的相位校正。随着噪声的降低，对于三步相位测量轮廓术，在校正相位的均方根误差分析中，与未进行校准相比，进行所提出的伽马校准后相位误差将降低60倍，而未校准时降低33倍。
