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Improved phase-unwrapping method using geometric constraints

Guangliang Du, Minmin Wang, Canlin Zhou, Shuchun Si, Hui Li, Zhenkun Lei, Yanjie Li
2017 Journal of Modern Optics  
Zhang et.al. proposed an enhanced two-frequency phase-shifting method to use geometric constraints of digital fringe projection(DFP) to reduce the noise impact due to the large frequency ratio.  ...  In this paper, we proposed an improved method, which eliminates the system calibration and determination in Zhang's method,meanwhile does not need to use the low frequency fringe pattern.  ...  Conclusion In this paper, we propose an improved phase-unwrapping method using geometric constraints.  ... 
doi:10.1080/09500340.2017.1284279 fatcat:hic4cgem25gnpejohjrtdb5mfe

Deep-learning-enabled geometric constraints and phase unwrapping for single-shot absolute 3D shape measurement [article]

Jiaming Qian, Shijie Feng, Tianyang Tao, Yan Hu, Yixuan Li, Qian Chen, Chao Zuo
2020 arXiv   pre-print
The stereo phase unwrapping (SPU) technologies based on geometric constraints can eliminate phase ambiguity without projecting any additional fringe patterns, which maximizes the efficiency of the retrieval  ...  Inspired by the recent success of deep learning technologies for phase analysis, we demonstrate that deep learning can be an effective tool that organically unifies the phase retrieval, geometric constraints  ...  constraints and phase unwrapping method.  ... 
arXiv:2001.01439v1 fatcat:675hcmimrre7foj4tqqg4objiq

Enhanced two-frequency phase-shifting method

Jae-Sang Hyun, Song Zhang
2016 Applied Optics  
This paper proposes a method to use geometric constraints of digital fringe projection system to substantially reduce the noise impact by allowing the use of more than one period of equivalent phase map  ...  for temporal phase unwrapping.  ...  SUMMARY This paper has presented a method to substantially improve the conventional two-frequency phase-shifting algorithm by using geometric constraints of the DFP system.  ... 
doi:10.1364/ao.55.004395 pmid:27411193 fatcat:7qqlonyazbgqljxckcfl6k27ie

Enhanced dual-frequency pattern scheme based on spatial-temporal fringes method

Minmin Wang, Canlin Zhou, Shuchun Si, Zhenkun Lei, Xiaolei Li, Hui Li, YanJie Li
2018 Journal of Modern Optics  
The low frequency phase is obtained from two low frequency fringe patterns by the STF method, so the signal lobes can be extracted accurately as they are far away from each other.  ...  One of the major challenges of employing a dual-frequency phase-shifting algorithm for phase retrieval is its sensitivity to noise.  ...  geometric constraints method is used to unwrap the low frequency phase.  ... 
doi:10.1080/09500340.2018.1455908 fatcat:nfdtxrhoxzbnxbcwozyp2e7sxq

Three-dimensional absolute shape measurement by combining binary statistical pattern matching with phase-shifting methods

Yatong An, Song Zhang
2017 Applied Optics  
The coarse correspondence map is further refined by using the wrapped phase as a constraint. We then use the refined correspondence map to determine a fringe order for absolute phase unwrapping.  ...  This paper presents a novel method that leverages the stereo geometric relationship between projector and camera for absolute phase unwrapping on a standard one-projector and one-camera structured light  ...  To our knowledge, none of the existing temporal phase-unwrapping methods fully utilizes the geometric constraints of the structured light system for fringe-order determination.  ... 
doi:10.1364/ao.56.005418 pmid:29047499 fatcat:fl7hbjfrjfffpfpatoxmxd2ytu

Improvement of Phase Unwrapping Algorithms by Epipolar Constraints

Johannes Köhler, Jan C. Peters, Tobias Nöll, Didier Stricker
2015 Proceedings of the 10th International Conference on Computer Vision Theory and Applications  
In this paper we suggest to support phase unwrapping algorithms by additional constraints induced by the scanning setup.  ...  We demonstrate this by exemplarily integrating the candidate map into a local path following and a global minimum norm unwrapping method.  ...  We believe that existing unwrapping methods can be used to achieve this and thus suggest to use the candidate map as reasonable preprocessing step for any classical phase unwrapping method.  ... 
doi:10.5220/0005271404720479 dblp:conf/visapp/KohlerPNS15 fatcat:3222rhothzeo5m7zl76uen5lum

Motion-induced error reduction by combining Fourier transform profilometry with phase-shifting profilometry

Beiwen Li, Ziping Liu, Song Zhang
2016 Optics Express  
The proposed method is composed of three major steps: Step 1 is to extract continuous relative phase maps for each isolated object with single-shot FTP method and spatial phase unwrapping; Step 2 is to  ...  obtain an absolute phase map of the entire scene using PSP method, albeit motion-induced errors exist on the extracted absolute phase map; and Step 3 is to shift the continuous relative phase maps from  ...  Phase unwrapping using geometric constraint As recently proposed by An et al. [25], one of the methods that removes 2π discontinuities on a wrapped phase map is by using geometric constraints.  ... 
doi:10.1364/oe.24.023289 pmid:27828393 fatcat:4r4yuw6rkfd4pkxkv23jf7r3c4

Absolute Phase Retrieval Using One Coded Pattern and Geometric Constraints of Fringe Projection System

Xu Yang, Chunnian Zeng, Jie Luo, Yu Lei, Bo Tao, Xiangcheng Chen
2018 Applied Sciences  
Compared with the conventional method, the measurement depth range is significantly improved. Finally, the wrapped phase can be unwrapped for absolute phase map.  ...  Based on geometric constraints of fringe projection system, the minimum fringe order map can be created, upon which the fringe order can be calculated from the code word.  ...  For example, at point A, Geometric Constraints for Phase Unwrapping An et al.  ... 
doi:10.3390/app8122673 fatcat:sedojzha4bhbpfwcvmywc24gsi

Fast 3D Surface Measurement with Wrapped Phase and Pseudorandom Image

Liu, He, Hu, Liu
2019 Sensors  
In this paper, we present a wrapped phase and pseudorandom image method and develop an experimental system aiming to avoid the process of phase unwrapping.  ...  The most critical step in our new methodology is using the wrapped phase and the epipolar constraint between one camera and a projector, which can obtain several candidate 3D points within the measurement  ...  [10] were interested in using the geometric constraints between multiple cameras and projectors to overcome the obstacle of wrapped phase periodicity.  ... 
doi:10.3390/s19194185 fatcat:zpp5wkrm7jdstpzdulf5ibgjce

Single-shot absolute 3D shape measurement with Fourier transform profilometry

Beiwen Li, Yatong An, Song Zhang
2016 Applied Optics  
By using geometric constraints, an absolute phase map can be retrieved point-by-point from one single grayscale fringe image.  ...  the absolute phase map solely from one single grayscale fringe image.  ...  Fig. 3 . 3 Concept of removing a 2π jump of a low-frequency phase map by using the minimum phase map determined from geometric constraints.  ... 
doi:10.1364/ao.55.005219 pmid:27409213 fatcat:uw54bkgw65ekpm6kg43zc37lsu

PURE: Scalable Phase Unwrapping with Spatial Redundant Arcs [article]

Ravi Lanka
2018 arXiv   pre-print
Phase unwrapping is a key problem in many coherent imaging systems, such as synthetic aperture radar (SAR) interferometry.  ...  A general formulation for redundant integration of finite differences for phase unwrapping (Costantini et al., 2010) was shown to produce a more reliable solution by exploiting redundant differential estimates  ...  Acknowledgments We would like to thank Piyush Agram for introducing us to Phase Unwrapping and Redundant Arcs technique and for the numerous discussion that shaped the problem definition.  ... 
arXiv:1805.00321v2 fatcat:vbu2mzlg3jhmhdnsuplzbjf7ya

Susceptibility artefact correction using dynamic graph cuts: Application to neurosurgery

Pankaj Daga, Tejas Pendse, Marc Modat, Mark White, Laura Mancini, Gavin P. Winston, Andrew W. McEvoy, John Thornton, Tarek Yousry, Ivana Drobnjak, John S. Duncan, Sebastien Ourselin
2014 Medical Image Analysis  
A phase unwrapping algorithm is presented that can efficiently compute the B0 magnetic field inhomogeneity map as well as the uncertainty associated with the estimated solution through the use of dynamic  ...  The proposed method combines fieldmap and image registration based correction techniques in a unified framework.  ...  Section 5 describes how uncertainty information can be computed from the phase unwrapping step and can be used with an image registration method to further improve results.  ... 
doi:10.1016/j.media.2014.06.008 pmid:25047865 pmcid:PMC6742505 fatcat:fhwo3snw5fhndmox4zavxxqvh4

Efficient Multi-frequency Phase Unwrapping Using Kernel Density Estimation [chapter]

Felix Järemo Lawin, Per-Erik Forssén, Hannes Ovrén
2016 Lecture Notes in Computer Science  
In this paper we introduce an efficient method to unwrap multi-frequency phase estimates for time-of-flight ranging.  ...  The intended Kinect v2 use case is scenes with less than 8m range, and for such cases we observe consistent improvements, while maintaining real-time performance.  ...  Another way to unwrap the time-of-flight phase shift is to use surface reflectivity constraints.  ... 
doi:10.1007/978-3-319-46493-0_11 fatcat:azywisud6fgbbejwq7bk7l76vu

Efficient Multi-Frequency Phase Unwrapping using Kernel Density Estimation [article]

Felix Järemo Lawin, Per-Erik Forssén, Hannes Ovrén
2016 arXiv   pre-print
In this paper we introduce an efficient method to unwrap multi-frequency phase estimates for time-of-flight ranging.  ...  The intended Kinect v2 use case is scenes with less than 8m range, and for such cases we observe consistent improvements, while maintaining real-time performance.  ...  Another way to unwrap the time-of-flight phase shift is to use surface reflectivity constraints.  ... 
arXiv:1608.05209v1 fatcat:muqcfbi2avam7bcf6ursisg2j4

Assessment of Thermal Environment in a Kitchen with a New Ventilation System

Sumei Liu, Xiaojie Zhou, Xuan Liu, Xiaorui Lin, Ke Qing, Weizhen Zhang, Jian Li, Jiankai Dong, Dayi Lai, Qingyan Chen, S.I Tanabe, H. Zhang (+7 others)
2019 E3S Web of Conferences  
TSV was improved with the new ventilation system.  ...  This investigation developed a new ventilation system for Chinese kitchens to improve thermal comfort level.  ...  [10] were interested in using the geometric constraints between multiple cameras and projectors to overcome the obstacle of wrapped phase periodicity.  ... 
doi:10.1051/e3sconf/201911102034 fatcat:jzzmswx545gtjhabfewqupsdu4
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