光学学报, 2018, 38 (11): 1112002, 网络出版: 2019-05-09
双投影结构光三维测量中重叠相移光栅的分离方法 下载: 1160次
Separation Method of Overlapping Phase-Shift Gratings in Three-Dimensional Measurement of Double Projection Structured Light
测量 分离算法 重叠相移光栅 结构光 三维测量 多投影 点云生成 measurement separation algorithm overlapping phase-shift grating structured light three-dimensional measurement multi-projection point cloud generation
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。
Abstract
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.
白景湘, 曲兴华, 冯维, 张福民. 双投影结构光三维测量中重叠相移光栅的分离方法[J]. 光学学报, 2018, 38(11): 1112002. Jingxiang Bai, Xinghua Qu, Wei Feng, Fumin Zhang. Separation Method of Overlapping Phase-Shift Gratings in Three-Dimensional Measurement of Double Projection Structured Light[J]. Acta Optica Sinica, 2018, 38(11): 1112002.