Parallel Single-Pixel Imaging: A General Method for Direct–Global Separation and 3D Shape Reconstruction Under Strong Global Illumination

International Conference on Optical and Photonic Engineering (icOPEN 2022)

et al. 2023

High-accuracy 3-D shape measurement of turbine blade is important for manufacturing engine and aircraft's safety. At present, the most commonly used three-coordinate measuring machine in the industrial field may cause scratches on the surface of turbine blade. Optical 3-D measurement methods, such as fringe projection profilometry, are unable to carry out targeted measurement of geometric structures with different levels of precision. This paper presents an automatic measurement method based on pneumatic gripper and 6-axis robot. The proposed composite system includes global sensor with large scanning range and local sensor with high accuracy, which can perform 3-D reconstruction with specific resolution for different positions of turbine blade. We use a 6-axis robot and pneumatic gripper to grasp the turbine blade automatically. The 3-D scanning is completed according to the viewpoints planned in advance. The point cloud data of different angles are aligned to obtain a high precision 3-D model of turbine blade surface. The experimental results show that the proposed automatic scanning method can effectively avoid the measurement error caused by manual grasping operation. On the basis of complete 3-D measurement of the whole surface, more dense point cloud data are obtained for fine structures such as blade edge. Our result is of great significance to the field of industrial measurement.

Section: Composite Optical Measurement Methodsmentioning

confidence: 99%

An automated 3D shape measurement method for turbine blade using a 6-axis robot

Wang

International Conference on Optical and Photonic Engineering (icOPEN 2022)

et al. 2023

“…PSI improves data acquisition efficiency because the size of the visible region of each pixel in the FPA is confined within a local region when they considered independent units for SI [14]. Thus, based on the theory of Fourier-based SI [16], illuminating a series of sinusoid patterns can reconstruct the image of the visible region for each pixel (Fig.…”

Section: Principles Of Psimentioning

confidence: 99%

“…Parallel single-pixel imaging (PSI) [14] method is introduced to extend traditional SI methods to FPA (Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

“…PSI by Fourier-based SI [16] is focused on in this study. PSI has been applied in the field of 3D reconstruction in the presence of global illumination [14], [17], where PSI is able to separate direct and global illumination, thereby achieving 3D shape reconstruction under global illumination. Data acquisition efficiency is improved for PSI because the number of projected patterns depends linearly on the total resolution of the projector.…”

Section: Introductionmentioning

confidence: 99%

“…Data acquisition efficiency is improved for PSI because the number of projected patterns depends linearly on the total resolution of the projector. Such efficiency is solved by the adoption of local region extension (LRE) method [14], which only capture the local visible region (Fig. 1), and is implemented by three stages.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Robustness analysis of parallel single-pixel imaging

International Conference on Optical and Photonic Engineering (icOPEN 2022)

et al. 2023

Single-pixel imaging (SI) methods have been widely studied in recent years. However, most existing researches have illustrated SI as an attractive prospect when multipixel sensors are not preferable due to cost or technological constraints. Parallel single-pixel imaging (PSI) has been introduced recently such that SI techniques is also attractive when multipixel sensors are easily obtained and provides new possibilities to traditional challenging problems. By treating each pixel on the camera as an independent SI unit, PSI captures light transport coefficients (LTCs) in highly efficient manner, and separates direct illumination and global illumination, thereby enabling 3D reconstruction under global illumination. Localization stage is of great importance for PSI, where the approximate information for visible region is obtained. In this paper, we analyze the robustness property of PSI with respective to localization stage. Robustness property of PSI states that the accuracy of 3D reconstruction data by PSI is insensitive to errors incurred in the localization stage. Firstly, we show this property from a theoretically aspect. Then, we conduct two experiments to test this property. Lastly, we also show that satisfactory 3D reconstruction results can be obtained when only partial frequencies are captured in the localization stage for a higher efficient data capture procedure.

Projective Parallel Single-Pixel Imaging to Overcome Global Illumination in 3D Structure Light Scanning

Lecture Notes in Computer Science

et al. 2022

Self Cite

We present projective parallel single-pixel imaging (pPSI), a 3D photography method that provides a robust and efficient way to analyze the light transport behavior and enables separation of light effect due to global illumination, thereby achieving 3D structured light scanning under global illumination. The light transport behavior is described by the light transport coefficients (LTC), which contain complete information for a projector-camera pair, and is a 4D data set. However, the capture of LTC is generally time consuming. The 4D LTC in pPSI are reduced to projection functions, thereby enabling a highly efficient data capture process. We introduce the local maximum constraint, which provides constraint for the location of candidate correspondence matching points when projections are captured. Local slice extension (LSE) method is introduced to accelerate the capture of projection functions. Optimization is conducted for pPSI under several situations. The number of projection functions required for pPSI is optimized and the influence of capture ratio in LSE on the accuracy of the correspondence matching points is investigated. Discussions and experiments include two typical kinds of global illuminations: inter-reflections and subsurface scattering. The proposed method is validated with several challenging scenarios, and outperforms the state-ofthe-art methods.