一种消除周期性毛刺相位误差的互补格雷码双 N 步相移法

互补格雷码双 N 步相移法因其具有鲁棒性好、检测精度高等特点在条纹投影轮廓术领域成为研究热点。 然而,传统互补格雷码双 N 步相移法存在检测效率低以及未消除周期性毛刺相位误差的问题。 针对这些问题,本文对传统互补格雷码双 N步相移法进行改进消除周期性毛刺相位误差,首先通过相机捕获形变条纹图像并计算出两组截断相位,然后利用两组截断相位的相关性消除检测数据中的相位差、周期性毛刺相位误差,再对两组截断相位进行融合,最后通过互补格雷码相位展开法对融合后的截断相位进行相位展开。 实验得出本文方法在检测效率不变的情况下,能有效消除周期性毛刺相位误差,得到高精度展开相位,相比于未消除周期性毛刺相位误差的互补格雷码双 N 步相移法,本文检测方法精度提高了约 24. 57% ,相比于互补格雷码 N 步相移法,本文检测方法精度提高了约 6. 29% 。

A complementary Gray code double N-step phase-shifting method for eliminating periodic spurious tones phase errors

The complementary Gray code double N-step phase-shifting method has become a research hotspot in the field of fringeprojection profilometry because of its good robustness and high detection accuracy. However, the traditional complementary Gray codedouble N-step phase-shifting method has the problems of low detection efficiency and does not eliminate the periodic spurious tones phaseerror. To solve these problems, the traditional complementary Gray code double N-step phase-shifting method is improved to eliminateperiodic spurious tones phase errors in this paper. Firstly, the deformed fringe images are captured by camera to calculate two groups ofwrapped phases. Next, the correlation of the two groups of wrapped phases is used to eliminate the phase difference and periodic spurioustones phase error in the detection data, and the two groups of wrapped phases are fused. Finally, the fused wrapped phase is unwrappedby the complementary Gray code phase unwrapping method. The experimental results show that the method in this paper could effectivelyeliminate the periodic spurious tones phase error and obtain the high-precision unwrapped phase, compared to the complementary Graycode double N-step phase-shifting method that does not eliminate periodic spurious tones phase errors, the accuracy of the detectionmethod in this paper has been improved by about 24. 57% . Compared with the complementary Gray code N-step phase-shifting method,the accuracy of the detection method in this paper has been improved by about 6. 29% .Keywords:double N-step phase shift method; wrapped phase; periodic spurious tones ph