双投影结构光三维测量中重叠相移光栅的分离方法
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摘要
在结构光的三维测量中,单投影仪单相机的测量结构在测量复杂物体时容易出现遮挡与阴影现象,从而影响了测量数据的完整性;使用双投影单相机的测量结构可扩展成像范围,减小阴影部分的面积,提高测量效率,但从部分重叠的相移光栅中分离出原始投影信号是该方法的难点。在分析传统四步相移法的基础上,提出了一种基于灰度互补关系的重叠相移光栅分离方法,该方法通过调整投影的相移光栅的时间及次序,在不改变原有测量系统结构的基础上有效消除了重叠部分的干扰信号;为了验证该分离方法的有效性,搭建测量系统进行相关实验。结果表明:利用互补关系可以实现重叠相移光栅信号的准确分离,获取完整的点云数据,同时也提高了测量速度。
In the three-dimensional measurement of structured light, the measurement structure only with a single projector is prone to occlusion and shadow in the measurement of complex objects and thus the integrity of measurement data is influenced. In contrast, the measurement structure with double projectors can broaden the imaging area and reduce the shadowing region, and thus the measurement efficiency is improved. However, it is still difficult to separate the original projection signals from the partially overlapping phase-shift gratings for this method. On the basis of the analysis of the conventional four-step phase-measuring method, a separation method of overlapping phase-shift gratings is proposed via the complementarity of gray scales, in which the invalid overlapping signals are effectively eliminated by adjusting the time and sequence of the projected phase-shift gratings while keeping the original measuring structure. As for the verification of the effectiveness of the above separation method, a measurement system is established to conduct the related experiments. The results show that the complementarity of gray scales can be used to realize the accurate separation of overlapping phase-shift grating signals, obtain the complete point cloud data, and improve the measurement speed.
In the three-dimensional measurement of structured light, the measurement structure only with a single projector is prone to occlusion and shadow in the measurement of complex objects and thus the integrity of measurement data is influenced. In contrast, the measurement structure with double projectors can broaden the imaging area and reduce the shadowing region, and thus the measurement efficiency is improved. However, it is still difficult to separate the original projection signals from the partially overlapping phase-shift gratings for this method. On the basis of the analysis of the conventional four-step phase-measuring method, a separation method of overlapping phase-shift gratings is proposed via the complementarity of gray scales, in which the invalid overlapping signals are effectively eliminated by adjusting the time and sequence of the projected phase-shift gratings while keeping the original measuring structure. As for the verification of the effectiveness of the above separation method, a measurement system is established to conduct the related experiments. The results show that the complementarity of gray scales can be used to realize the accurate separation of overlapping phase-shift grating signals, obtain the complete point cloud data, and improve the measurement speed.
引文
[1] Wang J F, Zhang C, Zhu W W, et al. 3D scene reconstruction by multiple structured-light based commodity depth cameras[C]//Proceedings of 2012 IEEE International Conference on Acoustics, Speech and Signal Processing, March 25-30, 2012, Kyoto, Japan. New York: IEEE Signal Processing Society. 2012: 5429-5432.
[2] Xu J, Xi N, Zhang C, et al. Real-time 3D shape inspection system of automotive parts based on structured light pattern[J]. Optics & Laser Technology, 2011, 43(1): 1-8.
[3] Zheng D L, Da F P. Double-step phase-shifting algorithm for fringe-projection measurement[J]. Acta Optica Sinica, 2012, 32(5): 0512004. 郑东亮, 达飞鹏. 双步相移光栅投影测量轮廓术[J]. 光学学报, 2012, 32(5): 0512004.
[4] Zhang X, Li Y F, Zhu L M. Color code identification in coded structured light[J]. Applied Optics, 2012, 51(22): 5340-5356.
[5] Lei Z H, Li J B. Full automatic phase unwrapping method based on projected double spatial frequency fringes[J]. Acta Optica Sinica, 2006, 26(1): 39-42. 雷志辉, 李健兵. 基于双频投影条纹的全自动相位解包裹方法[J]. 光学学报, 2006, 26(1): 39-42.
[6] Gai S Y, Da F P. A new phase alignment method for digital projector in phase measuring profilometry[J]. Acta Automatica Sinica, 2008, 34(11): 1363-1368. 盖绍彦, 达飞鹏. 基于数字投影仪的光栅相位自校正方法[J]. 自动化学报, 2008, 34(11): 1363-1368.
[7] Zhang H Q. The research based on projected various fringes for curved-surface measurement[D]. Changsha: National University of Defense Technology, 2006: 14-20. 章寒清. 基于多频投影条纹的物体曲面测量方法研究[D]. 长沙: 国防科学技术大学, 2006: 14-20.
[8] Li Z W. Research on structured light 3D measuring technology and system based on digital fringe projection[D]. Wuhan: Huazhong University of Science and Technology, 2009: 11-17. 李中伟. 基于数字光栅投影的结构光三维测量技术与系统研究[D]. 武汉: 华中科技大学, 2009: 11-17.
[9] Cui Y J, Zhang W F, Li J X, et al. A method of Gamma correction in fringe projection measurement[J]. Acta Optica Sinica, 2015, 35(1): 0112002. 崔艳军, 张文峰, 李建欣, 等. 条纹投影三维测量的Gamma畸变校正方法[J]. 光学学报, 2015, 35(1): 0112002.
[10] Yamaguchi I, Ida T, Yokota M, et al. Surface shape measurement by phase-shifting digital holography with a wavelength shift[J]. Applied Optics, 2006, 45(29): 7610-7616.
[11] Zhao L W, Da F P, Zheng D L. Method for binary grating generation using defocused projection for three-dimensional measurement[J]. Acta Optica Sinica, 2016, 36(8): 0812005. 赵立伟, 达飞鹏, 郑东亮. 离焦投影三维测量的二值光栅生成方法[J]. 光学学报, 2016, 36(8): 0812005.
[12] Maimone A, Fuchs H. Reducing interference between multiple structured light depth sensors using motion[C]∥Proceedings of Conference on IEEE Virtual Reality, March 4-8, 2012, Costa Mesa, California, USA. New York: IEEE, 2012: 51-54.
[13] Wu J B, Sang B, Zhao H, et al. Double projecting measurement method of 3D object based on color CCD[J]. Laser & Infrared, 2001, 31(3): 187-189. 吴剑波, 桑波, 赵宏. 基于彩色摄像机的三维物体双投影测量法[J]. 激光与红外, 2001, 31(3): 187-189.
[14] Xiao C, Chen F, Zhong M. Method for improving measurement accuracy of inverse fringe[J]. Laser & Optoelectronics Progress, 2016, 53(11): 111204. 肖朝, 陈锋, 钟敏. 一种提升反向条纹测量精度的方法[J]. 激光与光电子学进展, 2016, 53(11): 111204.
[15] Yan Z Q, Yu L, Yang Y, et al. Beyond the interference problem: hierarchical patterns for multiple-projector structured light system[J]. Applied Optics, 2014, 53(17): 3621-3632.
[16] Du H B, Zhao H, Li B, et al. Demodulating the phase of phase-shifting shadow moiré using arbitrary phase shift[J]. Acta Optica Sinica, 2012, 32(9): 0912003. 杜虎兵, 赵宏, 李兵, 等. 任意相移阴影叠栅相位解调技术的研究[J]. 光学学报, 2012, 32(9): 0912003.
[17] Chen L, Deng W Y, Lou X P. Phase unwrapping method base on multi-frequency interferometry[J]. Optical Technique, 2012, 38(1): 73-78. 陈玲, 邓文怡, 娄小平. 基于多频外差原理的相位解包裹方法[J]. 光学技术, 2012, 38(1): 73-78.
[2] Xu J, Xi N, Zhang C, et al. Real-time 3D shape inspection system of automotive parts based on structured light pattern[J]. Optics & Laser Technology, 2011, 43(1): 1-8.
[3] Zheng D L, Da F P. Double-step phase-shifting algorithm for fringe-projection measurement[J]. Acta Optica Sinica, 2012, 32(5): 0512004. 郑东亮, 达飞鹏. 双步相移光栅投影测量轮廓术[J]. 光学学报, 2012, 32(5): 0512004.
[4] Zhang X, Li Y F, Zhu L M. Color code identification in coded structured light[J]. Applied Optics, 2012, 51(22): 5340-5356.
[5] Lei Z H, Li J B. Full automatic phase unwrapping method based on projected double spatial frequency fringes[J]. Acta Optica Sinica, 2006, 26(1): 39-42. 雷志辉, 李健兵. 基于双频投影条纹的全自动相位解包裹方法[J]. 光学学报, 2006, 26(1): 39-42.
[6] Gai S Y, Da F P. A new phase alignment method for digital projector in phase measuring profilometry[J]. Acta Automatica Sinica, 2008, 34(11): 1363-1368. 盖绍彦, 达飞鹏. 基于数字投影仪的光栅相位自校正方法[J]. 自动化学报, 2008, 34(11): 1363-1368.
[7] Zhang H Q. The research based on projected various fringes for curved-surface measurement[D]. Changsha: National University of Defense Technology, 2006: 14-20. 章寒清. 基于多频投影条纹的物体曲面测量方法研究[D]. 长沙: 国防科学技术大学, 2006: 14-20.
[8] Li Z W. Research on structured light 3D measuring technology and system based on digital fringe projection[D]. Wuhan: Huazhong University of Science and Technology, 2009: 11-17. 李中伟. 基于数字光栅投影的结构光三维测量技术与系统研究[D]. 武汉: 华中科技大学, 2009: 11-17.
[9] Cui Y J, Zhang W F, Li J X, et al. A method of Gamma correction in fringe projection measurement[J]. Acta Optica Sinica, 2015, 35(1): 0112002. 崔艳军, 张文峰, 李建欣, 等. 条纹投影三维测量的Gamma畸变校正方法[J]. 光学学报, 2015, 35(1): 0112002.
[10] Yamaguchi I, Ida T, Yokota M, et al. Surface shape measurement by phase-shifting digital holography with a wavelength shift[J]. Applied Optics, 2006, 45(29): 7610-7616.
[11] Zhao L W, Da F P, Zheng D L. Method for binary grating generation using defocused projection for three-dimensional measurement[J]. Acta Optica Sinica, 2016, 36(8): 0812005. 赵立伟, 达飞鹏, 郑东亮. 离焦投影三维测量的二值光栅生成方法[J]. 光学学报, 2016, 36(8): 0812005.
[12] Maimone A, Fuchs H. Reducing interference between multiple structured light depth sensors using motion[C]∥Proceedings of Conference on IEEE Virtual Reality, March 4-8, 2012, Costa Mesa, California, USA. New York: IEEE, 2012: 51-54.
[13] Wu J B, Sang B, Zhao H, et al. Double projecting measurement method of 3D object based on color CCD[J]. Laser & Infrared, 2001, 31(3): 187-189. 吴剑波, 桑波, 赵宏. 基于彩色摄像机的三维物体双投影测量法[J]. 激光与红外, 2001, 31(3): 187-189.
[14] Xiao C, Chen F, Zhong M. Method for improving measurement accuracy of inverse fringe[J]. Laser & Optoelectronics Progress, 2016, 53(11): 111204. 肖朝, 陈锋, 钟敏. 一种提升反向条纹测量精度的方法[J]. 激光与光电子学进展, 2016, 53(11): 111204.
[15] Yan Z Q, Yu L, Yang Y, et al. Beyond the interference problem: hierarchical patterns for multiple-projector structured light system[J]. Applied Optics, 2014, 53(17): 3621-3632.
[16] Du H B, Zhao H, Li B, et al. Demodulating the phase of phase-shifting shadow moiré using arbitrary phase shift[J]. Acta Optica Sinica, 2012, 32(9): 0912003. 杜虎兵, 赵宏, 李兵, 等. 任意相移阴影叠栅相位解调技术的研究[J]. 光学学报, 2012, 32(9): 0912003.
[17] Chen L, Deng W Y, Lou X P. Phase unwrapping method base on multi-frequency interferometry[J]. Optical Technique, 2012, 38(1): 73-78. 陈玲, 邓文怡, 娄小平. 基于多频外差原理的相位解包裹方法[J]. 光学技术, 2012, 38(1): 73-78.