State of the art on vision-based structured light systems for 3D measurements

Structured light systems are popular in part because they can be constructed from off-the-shelf low cost components. In this paper we quantitatively show how common design parameters affect precision and accuracy in such systems, supplying a much needed guide for practitioners. Our quantitative measure is the established VDI/VDE 2634 (Part 2) guideline using precision made calibration artifacts. Experiments are performed on our own structured light setup, consisting of two cameras and a projector. We place our focus on the influence of calibration design parameters, the calibration procedure and encoding strategy and present our findings. Finally, we compare our setup to a state of the art metrology grade commercial scanner. Our results show that comparable, and in some cases better, results can be obtained using the parameter settings determined in this study.

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Temporal Matrices Mapping-Based Calibration Method for Event-Driven Structured Light Systems

IEEE Sensors Journal ◽

10.1109/jsen.2020.3016833 ◽

2021 ◽

Vol 21 (2) ◽

pp. 1799-1808

Author(s):

Guijin Wang ◽

Chenchen Feng ◽

Xiaowei Hu ◽

Huazhong Yang

Keyword(s):

Structured Light ◽

Calibration Method ◽

Event Driven ◽

Structured Light Systems

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Calibration Method for Line-Structured Light Three-Dimensional Measurements Based on a Single Circular Target

Applied Sciences ◽

10.3390/app12020588 ◽

2022 ◽

Vol 12 (2) ◽

pp. 588

Author(s):

Jun Wang ◽

Xuexing Li

Keyword(s):

Structured Light ◽

Three Dimensional ◽

Calibration Method ◽

Optical Center ◽

3D Measurements ◽

Light Plane ◽

Laser Projector ◽

Dimensional Measurements ◽

Intersection Points ◽

Circular Target

Single circular targets are widely used as calibration objects during line-structured light three-dimensional (3D) measurements because they are versatile and easy to manufacture. This paper proposes a new calibration method for line-structured light 3D measurements based on a single circular target. First, the target is placed in several positions and illuminated by a light beam emitted from a laser projector. A camera captures the resulting images and extracts an elliptic fitting profile of the target and the laser stripe. Second, an elliptical cone equation defined by the elliptic fitting profile and optical center of the camera is established based on the projective geometry. By combining the obtained elliptical cone and the known diameter of the circular target, two possible positions and orientations of the circular target are determined and two groups of 3D intersection points between the light plane and the circular target are identified. Finally, the correct group of 3D intersection points is filtered and the light plane is progressively fitted. The accuracy and effectiveness of the proposed method are verified both theoretically and experimentally. The obtained results indicate that a calibration accuracy of 0.05 mm can be achieved for an 80 mm × 80 mm planar target.

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