Single-Shot Three-Dimensional Measurement by Fringe Analysis Network

Fringe projection profilometry (FPP) has been broadly applied in three-dimensional (3D) measurements, but the existing multi-shot methods, which mostly utilize phase-shifting techniques, are heavily affected by the disturbance of vibration and cannot be used in dynamic scenes. In this work, a single...

Full description

Bibliographic Details
Main Authors: Mingzhu Wan, Lingbao Kong, Xing Peng
Format: Article
Language:English
Published: MDPI AG 2023-04-01
Series:Photonics
Subjects:
Online Access:https://www.mdpi.com/2304-6732/10/4/417
_version_ 1797603836364324864
author Mingzhu Wan
Lingbao Kong
Xing Peng
author_facet Mingzhu Wan
Lingbao Kong
Xing Peng
author_sort Mingzhu Wan
collection DOAJ
description Fringe projection profilometry (FPP) has been broadly applied in three-dimensional (3D) measurements, but the existing multi-shot methods, which mostly utilize phase-shifting techniques, are heavily affected by the disturbance of vibration and cannot be used in dynamic scenes. In this work, a single-shot 3D measurement method using a deep neural network named the Fringe Analysis Network (FrANet) is proposed. The FrANet is composed of a phase retrieval subnetwork, phase unwrapping subnetwork, and refinement subnetwork. The combination of multiple subnetworks can help to recover long-range information that is missing for a single U-Net. A two-stage training strategy in which the FrANet network is pre-trained using fringe pattern reprojection and fine-tuned using ground truth phase maps is designed. Such a training strategy lowers the number of ground truth phase maps in the data set, saves time during data collection, and maintains the accuracy of supervised methods in real-world setups. Experimental studies were carried out on a setup FPP system. In the test set, the mean absolute error (MAE) of the refined absolute phase maps was 0.0114 rad, and the root mean square error (RMSE) of the 3D reconstruction results was 0.67 mm. The accuracy of the proposed method in dynamic scenes was evaluated by measuring moving standard spheres. The measurement of the sphere diameter maintained a high accuracy of 84 μm at a speed of 0.759 m/s. Two-stage training only requires 8800 fringe images in data acquisition, while supervised methods require 96,000 fringe images for the same number of iterations. Ablation studies verified the effectiveness of two training stages and three subnetworks. The proposed method achieved accurate single-shot 3D measurements comparable to those obtained using supervised methods and has a high data efficiency. This enables the accurate 3D shape measurement of moving or vibrating objects in industrial manufacturing and allows for further exploration of network architecture and training strategy with few training samples for single-shot 3D measurement.
first_indexed 2024-03-11T04:37:43Z
format Article
id doaj.art-d93cd9c0c9614b8da43a8fc08ea6ea5b
institution Directory Open Access Journal
issn 2304-6732
language English
last_indexed 2024-03-11T04:37:43Z
publishDate 2023-04-01
publisher MDPI AG
record_format Article
series Photonics
spelling doaj.art-d93cd9c0c9614b8da43a8fc08ea6ea5b2023-11-17T20:57:45ZengMDPI AGPhotonics2304-67322023-04-0110441710.3390/photonics10040417Single-Shot Three-Dimensional Measurement by Fringe Analysis NetworkMingzhu Wan0Lingbao Kong1Xing Peng2Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, School of Information Science and Technology, Fudan University, Shanghai 200438, ChinaShanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, School of Information Science and Technology, Fudan University, Shanghai 200438, ChinaCollege of Intelligent Science and Technology, National University of Defense Technology, Changsha 410073, ChinaFringe projection profilometry (FPP) has been broadly applied in three-dimensional (3D) measurements, but the existing multi-shot methods, which mostly utilize phase-shifting techniques, are heavily affected by the disturbance of vibration and cannot be used in dynamic scenes. In this work, a single-shot 3D measurement method using a deep neural network named the Fringe Analysis Network (FrANet) is proposed. The FrANet is composed of a phase retrieval subnetwork, phase unwrapping subnetwork, and refinement subnetwork. The combination of multiple subnetworks can help to recover long-range information that is missing for a single U-Net. A two-stage training strategy in which the FrANet network is pre-trained using fringe pattern reprojection and fine-tuned using ground truth phase maps is designed. Such a training strategy lowers the number of ground truth phase maps in the data set, saves time during data collection, and maintains the accuracy of supervised methods in real-world setups. Experimental studies were carried out on a setup FPP system. In the test set, the mean absolute error (MAE) of the refined absolute phase maps was 0.0114 rad, and the root mean square error (RMSE) of the 3D reconstruction results was 0.67 mm. The accuracy of the proposed method in dynamic scenes was evaluated by measuring moving standard spheres. The measurement of the sphere diameter maintained a high accuracy of 84 μm at a speed of 0.759 m/s. Two-stage training only requires 8800 fringe images in data acquisition, while supervised methods require 96,000 fringe images for the same number of iterations. Ablation studies verified the effectiveness of two training stages and three subnetworks. The proposed method achieved accurate single-shot 3D measurements comparable to those obtained using supervised methods and has a high data efficiency. This enables the accurate 3D shape measurement of moving or vibrating objects in industrial manufacturing and allows for further exploration of network architecture and training strategy with few training samples for single-shot 3D measurement.https://www.mdpi.com/2304-6732/10/4/4173D measurementfringe projectionstructured lightdeep learningsingle-shot
spellingShingle Mingzhu Wan
Lingbao Kong
Xing Peng
Single-Shot Three-Dimensional Measurement by Fringe Analysis Network
Photonics
3D measurement
fringe projection
structured light
deep learning
single-shot
title Single-Shot Three-Dimensional Measurement by Fringe Analysis Network
title_full Single-Shot Three-Dimensional Measurement by Fringe Analysis Network
title_fullStr Single-Shot Three-Dimensional Measurement by Fringe Analysis Network
title_full_unstemmed Single-Shot Three-Dimensional Measurement by Fringe Analysis Network
title_short Single-Shot Three-Dimensional Measurement by Fringe Analysis Network
title_sort single shot three dimensional measurement by fringe analysis network
topic 3D measurement
fringe projection
structured light
deep learning
single-shot
url https://www.mdpi.com/2304-6732/10/4/417
work_keys_str_mv AT mingzhuwan singleshotthreedimensionalmeasurementbyfringeanalysisnetwork
AT lingbaokong singleshotthreedimensionalmeasurementbyfringeanalysisnetwork
AT xingpeng singleshotthreedimensionalmeasurementbyfringeanalysisnetwork