3D shape measurement with temporal phase unwrapping and 1-D continuous wavelet transform

2021 ◽  
Author(s):  
Susana L. Burnes-Rudecino ◽  
José de Jesús Villa Hernández ◽  
Gamaliel Moreno ◽  
Ismael de la Rosa ◽  
Efrén González ◽  
...  
Keyword(s):  
Wavelet Transform ◽  
Continuous Wavelet Transform ◽  
Phase Unwrapping ◽  
Shape Measurement ◽  
Continuous Wavelet ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Temporal Phase

3D shape measurement by two-steps temporal phase unwrapping: hybrid method

2019 ◽  
Author(s):  
Jorge Luis Flores Nuñez ◽  
Adriana Silva ◽  
Jose A. Ferrari ◽  
Antonio Muñoz ◽  
Guillermo García Torales ◽  
...  
Keyword(s):  
Hybrid Method ◽  
Phase Unwrapping ◽  
Shape Measurement ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Temporal Phase

Fast 3D Shape Measurement of Complex Objects Combining S-transform Profilometry and Sub-Pixel Refinement

2020 ◽  
Author(s):  
Feng Lu ◽  
Jikun Yang
Keyword(s):  
Fringe Pattern ◽  
Vision System ◽  
Phase Unwrapping ◽  
Shape Measurement ◽  
Complex Objects ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Phase Slope ◽  
S Transform ◽  
Hybrid Function

Abstract In the fast 3D shape measurement of complex objects, the process of phase unwrapping affects the measurement accuracy and measurement speed. To omit phase unwrapping, a fast 3D shape measurement method is proposed based on S-transform profilometry and sub-pixel refinement. In this work, Deformed fringe pattern is analyzed based on S-transform to get wrapped phase. To reduce the effect of phase unwrapping, a stereo vision system is employed. Firstly, a deformed fringe pattern is directly used and a hybrid function is proposed to get an initial parallax. Secondly, a phase slope algorithm is proposed to confirm edge point. At last, sub-pixel parallax is refined fromIcoordinate. Experiments are carried out to verify the feasibility and advantage of the proposed method. Results verify that the proposed method can provide fast and accurate 3D shape measurement of complex objects, especially for discontinuous objects and shiny objects.

Stereo phase unwrapping using deep learning for single-shot absolute 3D shape measurement

2021 ◽  
Author(s):  
Jiaming Qian ◽  
Shejie Feng ◽  
Yixuan Li ◽  
Qian Chen ◽  
Chao Zuo
Keyword(s):  
Deep Learning ◽  
Phase Unwrapping ◽  
Shape Measurement ◽  
Single Shot ◽  
3D Shape ◽  
3D Shape Measurement

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.

scholarly journals Deep-learning-enabled geometric constraints and phase unwrapping for single-shot absolute 3D shape measurement

APL Photonics ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 046105 ◽  
Author(s):  
Jiaming Qian ◽  
Shijie Feng ◽  
Tianyang Tao ◽  
Yan Hu ◽  
Yixuan Li ◽  
...  
Keyword(s):  
Deep Learning ◽  
Phase Unwrapping ◽  
Geometric Constraints ◽  
Shape Measurement ◽  
Single Shot ◽  
3D Shape ◽  
3D Shape Measurement

Novel Method of Digital Holographic Profilometry

2014 ◽  
Vol 1006-1007 ◽  
pp. 857-862
Author(s):  
Qing Chen Bao ◽  
Shu Hai Jia ◽  
Yong Xu ◽  
Chao Jiang
Keyword(s):  
Low Cost ◽  
Measurement Techniques ◽  
Reference Beam ◽  
Phase Unwrapping ◽  
Shape Measurement ◽  
Object Beam ◽  
3D Shape ◽  
3D Shape Measurement ◽  
Continuous Object ◽  
Novel Method

The 3D shape measurement has been one of research hotspots in the field of Mechanical measurement. But general optical 3D shape measurement techniques can only measure the continuous object through the phase unwrapping. It’s very difficult to unwrap the phase of the discontinuous object. To solve this problem, a novel digital holographic interferometry used for measuring the 3D shape is proposed in this paper. In this method, holographic interferograms are generated by object beam and reference beam at different incident angles. Height information of every point at the object surface is extracted independently without the phase unwrapping, thus it can measure the discontinuous object. The simulation and initial experiment results suggest that the method is completely feasible and low-cost, so it has great potential to apply in the industrial production.

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