格雷码与六步相移编码融合的三维结构光学测量方法

孙帮勇; 吴思远

doi:10.11884/HPLPB202133.200242

格雷码与六步相移编码融合的三维结构光学测量方法

doi: 10.11884/HPLPB202133.200242

孙帮勇^{1, 2,},
吴思远^2,

1.
西安理工大学印刷包装与数字媒体学院，西安 710048
2.
中国科学院西安光学精密机械研究所光谱成像技术重点实验室，西安 710119

基金项目: 国家自然科学基金项目(62076199)；中国科学院光谱成像技术重点实验室基金项目(LSIT201801D)

详细信息

作者简介:
孙帮勇(1980—)，男，博士，副教授，从事多光谱成像技术研究；sunbangyong@xaut.edu.cn

吴思远(1991—)，男，硕士，工程师，从事结构光学设计与测量研究；wusiyuan@opt.ac.cn

中图分类号: O439
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- 被引次数: 0
出版历程
- 收稿日期: 2020-08-19
- 修回日期: 2020-12-18
- 刊出日期: 2021-01-07

Structured light technology based on gray code and six-step phase shift method

Sun Bangyong^{1, 2
,},
Wu Siyuan^2
,

1.
College of Printing, Packaging Engineering and Digital Media, Xi’an University of Technology, Xi’an 710048, China
2.
Key Laboratory of Spectral Imaging Technology, Xi'an Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Xi'an 710119, China

摘要

摘要: 编码结构光技术是一种获取复杂目标三维结构的典型测量技术，其将编码后的结构光图案投射到待测物体表面进行调制、采集，并通过解码计算三维面形数据，可见编码方法是结构光三维测量技术的核心问题。然而，通用的格雷码编码方法和六步相移编码方法都存在一定缺陷，为此，以获取物体的高精度三维点云数据为目标，提出了一种融合格雷码与六步相移的结构光技术。首先，将格雷码结构光设计为7幅黑白相间的条纹周期图像，并通过投射角度解码操作将图像划分为多个区域；然后，设计六步相移结构光为6幅具有相位差的余弦周期图像，通过相位解包裹操作将每个子区域细分到单个像素单元；最后，融合以上两种编码结构光解码值，计算图像内每个空间点的绝对相位信息。仿真实验与实际测试实验显示，与传统六幅莫尔条纹结构光技术相比，融合结构光技术计算量较小，同时也克服了单独使用格雷码或相移技术所存在的问题，能够以较高精度获取物体目标的三维结构细节，为基于结构光的双目三维扫描系统提供一定理论依据。
- 三角测量原理 /
- 六步相移 /
- 格雷码 /
- 结构光 /
- 三维点云
Abstract: Structured light technology is a typical method for capturing the three-dimensional point cloud data of realistic objects. Structured light images are projected on the surface of the object, which are modulated by the height of the object. Then, the modulated structured light is captured by the camera. Finally, the triangulation principle is used to calculate the three-dimensional surface shape data. To scan the high-precision three-dimensional point cloud of the object, this paper proposes a structured light technology based on Gray code and six-step phase shift method. The structured light based on Gray code is composed of 7 black and white fringe periodic images, and the image can be divided into 128 areas through the gray code decoding operation; the structured light based on six-step phase shift is composed of 6 cosine periodic images with phase difference. Phase shift decoding can subdivide each of the 128 areas into a single pixel. Compared with the cumbersome calculation of six Moiré fringes, the proposed structured light technology based on six-step phase-shift method has less calculation. In the simulation experiment and actual test, the proposed structured light technology showed excellent performance.
- principle of triangulation /
- six-step phase shift /
- Gray code /
- structured light /
- cloud point

HTML全文

图 1 基于结构光的双目三维扫描设备示意图

Figure 1. Binocular three-dimensional scanning instrument based on structured light

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图 2 格雷码结构光示意图

Figure 2. Structured light images based on Gray code

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图 3 格雷码编码结构光图案从左至右依次为第一幅，第二幅，…，第七幅编码图像

Figure 3. The structured light based on Gray code. From left to right are the first，second，...，seventh coded image

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图 4 局部阈值的选取示意图

Figure 4. Schematic diagram of local threshold selection

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图 5 六步相移结构光图像第一行的像素值规律图，图像I₀的像素值周期规律对应I0曲线，依次类推

Figure 5. Schematic diagram of the pixel value rule of the structured light image based on six-step phase shift method

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图 6 格雷编码仿真解码图，图像被划分为128个区域

Figure 6. Gray coding simulation decoding diagram. The image is divided into 128 areas

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图 7 六步相移结构光仿真解码图

Figure 7. Decoding diagram of the structured light based on six-step phase-shift simulation

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图 8 格雷编码实际应用中的解码结果图

Figure 8. Picture of the decoding result in the actual application of Gray coding

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图 9 六步相移结构光实际应用中的解码结果图

Figure 9. Picture of decoding result in practical application of six-step phase shift structured light

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图 10 物体三维结构扫描结果对比图

Figure 10. Comparison of scanning results of three-dimensional structure of objects

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图 11 不同物体的三维结构扫描结果图

Figure 11. Scanning results of three-dimensional structures of different objects

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