scholarly journals A Small and High-Speed Driving Mechanism for 3D Shape Measurement in Monocular Endoscopy

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4887
Author(s):  
Yoshikazu Nakajima ◽  
Nobuyuki Tanigaki ◽  
Takaaki Sugino ◽  
Toshihiro Kawase ◽  
Shinya Onogi
Keyword(s):  
High Speed ◽  
Image Sensor ◽  
Shape Reconstruction ◽  
Shape Measurement ◽  
Driving Mechanism ◽  
Reconstruction Algorithms ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Shape Acquisition ◽  
Shape From Focus

Three-dimensional (3D) shape acquisition has been widely introduced to enrich quantitative analysis with the combination of object shape and texture, for example, surface roughness evaluation in industry and gastrointestinal endoscopy in medicine. Shape from focus is a promising technique to measure substance surfaces in 3D space because no occlusion problem appears in principle, as does with stereo shape measurement, which is another commonly used option. We have been developing endoscopic shape measurement devices and shape reconstruction algorithms. In this paper, we propose a mechanism for driving an image sensor reciprocated for the shape from focus of 3D shape measurement in monocular endoscopy. It uses a stepping motor and a planar-end cam, which transforms the motor rotation to imaging sensor reciprocation, to implement the shape from focus of 3D shape measurement in endoscopy. We test and discuss the device in terms of its driving accuracy and application feasibility for endoscopic 3D shape measurement.

scholarly journals High Speed 3D Shape Measurement with Temporal Fourier Transform Profilometry

2019 ◽  
Vol 9 (19) ◽  
pp. 4123 ◽  
Author(s):  
Haihua Zhang ◽  
Qican Zhang ◽  
Yong Li ◽  
Yihang Liu
Keyword(s):  
Fourier Transform ◽  
High Speed ◽  
Shape Measurement ◽  
Measurement Technology ◽  
Reconstruction Process ◽  
Measured Object ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Fourier Transform Profilometry ◽  
Dynamic Objects

A novel high-speed 3D shape measurement technology called temporal Fourier transform profilometry (TFTP for short) is proposed by combining the merits of Fourier transform profilometry (FTP) and phase-measuring profilometry (PMP). Instead of using the digital light projector, a mechanical projector is employed to generate multi-period phase-shifting fringe patterns sequentially. During the reconstruction process, the phase value of each pixel is calculated independently along the temporal axis and no spectrum filtering operation is performed in a spatial domain. Therefore, high-frequency components containing the detailed information of the measured object effectively remain. The proposed method is suitable for measuring isolated dynamic objects. Only one frame of deformed fringe pattern is required to retrieve one 3D shape of the measured object, so it has the obvious advantage if measuring the dynamic scene at a high speed. A low-cost self-made mechanical projector with fast projection speed is developed to execute the principle-proof experiments, whose results demonstrate the feasibility of measuring isolated dynamic objects.

scholarly journals High-speed real-time 3D shape measurement based on adaptive depth constraint

2018 ◽  
Vol 26 (17) ◽  
pp. 22440 ◽  
Author(s):  
Tianyang Tao ◽  
Qian Chen ◽  
Shijie Feng ◽  
Jiaming Qian ◽  
Yan Hu ◽  
...  
Keyword(s):  
Real Time ◽  
High Speed ◽  
Shape Measurement ◽  
3D Shape ◽  
3D Shape Measurement

FPGA-assisted high-precision, high-speed 3D shape measurement

2020 ◽  
Vol 315 ◽  
pp. 112366
Author(s):  
Duanmao Liu ◽  
Yinfei Pan ◽  
Rongsheng Lu
Keyword(s):  
High Precision ◽  
High Speed ◽  
Shape Measurement ◽  
3D Shape ◽  
3D Shape Measurement

Multilevel symmetric pattern design and optimization for high-speed and high-accuracy 3D shape measurement

2020 ◽  
Vol 126 ◽  
pp. 106103 ◽  
Author(s):  
Yajun Wang ◽  
Jae Sang Hyun ◽  
Song Zhang ◽  
Bin Luo ◽  
Ziping Liu ◽  
...  
Keyword(s):  
High Speed ◽  
High Accuracy ◽  
Shape Measurement ◽  
Pattern Design ◽  
Design And Optimization ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Symmetric Pattern

scholarly journals Improved Ternary Gray-Code Phase Unwrapping Algorithm for 3D Measurement Using a Binary Defocusing Technique

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1824
Author(s):  
Xu Yang ◽  
Houxing Lin ◽  
Jie Luo ◽  
Lei Chen ◽  
Yu Lei
Keyword(s):  
Conventional Method ◽  
High Speed ◽  
Gray Code ◽  
Phase Unwrapping ◽  
Shape Measurement ◽  
3D Measurement ◽  
Measuring Range ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Binary Defocusing

By using one-bit binary patterns instead of eight-bit sinusoidal ones, the binary defocusing techniques have been widely applied for high-speed 3D shape measurement. As projector defocusing is required, the phase unwrapping process of these techniques remains challenging. A recently proposed ternary Gray-code method can effectively increase the measurement speed by reducing the number of acquired coding patterns. However, it still has limitations, including the measuring range and a noise problem. To improve these, a new ternary Gray-code method is proposed by utilizing 2D modulation instead of the 1D modulation used in the conventional method. Simulations were conducted to compare these two methods, and the results verify that the proposed method reduces the variance in the introduced intermediate gray value by nearly 90%. Experiments were also carried out with the results verifying the superiority of the proposed method.

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