scholarly journals A Fringe Phase Extraction Method Based on Neural Network

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1664
Author(s):  
Wenxin Hu ◽  
Hong Miao ◽  
Keyu Yan ◽  
Yu Fu

In optical metrology, the output is usually in the form of a fringe pattern, from which a phase map can be generated and phase information can be converted into the desired parameters. This paper proposes an end-to-end method of fringe phase extraction based on the neural network. This method uses the U-net neural network to directly learn the correspondence between the gray level of a fringe pattern and the wrapped phase map, which is simpler than the exist deep learning methods. The results of simulation and experimental fringe patterns verify the accuracy and the robustness of this method. While it yields the same accuracy, the proposed method features easier operation and a simpler principle than the traditional phase-shifting method and has a faster speed than wavelet transform method.

2017 ◽  
Vol 31 (19-21) ◽  
pp. 1740088 ◽  
Author(s):  
Huaxia Deng ◽  
Ji Deng ◽  
Mengchao Ma ◽  
Jin Zhang ◽  
Liandong Yu ◽  
...  

A novel phase unwrapping method with five composite fringe patterns and phase-shifting method was proposed for three-dimensional information detection. The composite fringe patterns were composed of phase-shifted sinusoidal and stair phase-coding fringe patterns. The fringe patterns are five step phase-shifted. The relative phase and the stair code-words can be obtained simultaneously based on the five step phase-shifting algorithm. The monochrome composite structure has the improvement on the measurement speed and has the potential of solving the problem of color coupling and color imbalance. Combined with the modified minimum phase map theory, this method can provide more code-words for the full field measurement. Simulation and experimental results were presented in the final part to verify the flexibility and feasibility of the proposed method.


2021 ◽  
Vol 12 (1) ◽  
pp. 252
Author(s):  
Ke Wu ◽  
Min Li ◽  
Lei Lu ◽  
Jiangtao Xi

The reconstruction of moving objects based on phase shifting profilometry has attracted intensive interests. Most of the methods introduce the phase shift by projecting multiple fringe patterns, which is undesirable in moving object reconstruction as the errors caused by the motion will be intensified when the number of the fringe pattern is increased. This paper proposes the reconstruction of the isolated moving object by projecting two fringe patterns with different frequencies. The phase shift required by the phase shifting profilometry is generated by the object motion, and the model describing the motion-induced phase shift is presented. Then, the phase information in different frequencies is retrieved by analyzing the influence introduced by movement. Finally, the mismatch on the phase information between the two frequencies is compensated and the isolated moving object is reconstructed. Experiments are presented to verify the effectiveness of the proposed method.


2019 ◽  
Vol 21 (9) ◽  
pp. 095702 ◽  
Author(s):  
Shien Ri ◽  
Qinghua Wang ◽  
Peng Xia ◽  
Hiroshi Tsuda

2014 ◽  
Vol 3 (4) ◽  
Author(s):  
Yuankun Liu ◽  
Evelyn Olesch ◽  
Zheng Yang ◽  
Gerd Häusler

AbstractPhase measuring deflectometry (PMD) acquires the two components of the local surface gradient via a sequence of two orthogonal sinusoidal fringe patterns that have to be displayed and captured separately. We will demonstrate that the sequential process (different fringe directions, phase shifting) can be completely avoided by using a cross fringe pattern. With an optimized Fourier evaluation, high quality data of smooth optical surfaces can be acquired within one single shot. The cross fringe pattern allows for one more improvement of PMD: we will demonstrate a novel phase-shift technique, where a one-dimensional


2015 ◽  
Author(s):  
Mei Hui ◽  
Ming Liu ◽  
Liquan Dong ◽  
Xiaohua Liu ◽  
Yuejin Zhao

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