Performance analysis and evaluation of direct phase measuring deflectometry

P Zhao, N Gao, Z Zhang, F Gao, X Jiang - Optics and lasers in engineering, 2018 - Elsevier
Abstract Three-dimensional (3D) shape measurement of specular objects plays an important
role in intelligent manufacturing applications. Phase measuring deflectometry (PMD)-based …

Adaptive pixel-to-pixel projection intensity adjustment for measuring a shiny surface using orthogonal color fringe pattern projection

C Chen, N Gao, X Wang, Z Zhang - Measurement Science and …, 2018 - iopscience.iop.org
Abstract Three-dimensional (3D) shape measurement based on fringe pattern projection
techniques has been commonly used in various fields. One of the remaining challenges in …

An improved stair phase encoding method for absolute phase retrieval

C Zhou, T Liu, S Si, J Xu, Y Liu, Z Lei - Optics and Lasers in Engineering, 2015 - Elsevier
An improved phase unwrapping method is proposed to reduce the projection fringes in three-
dimensional (3D) surface measurement. Color fringe patterns are generated by encoding …

Activity recognition in residential spaces with internet of things devices and thermal imaging

K Naik, T Pandit, N Naik, P Shah - Sensors, 2021 - mdpi.com
In this paper, we design algorithms for indoor activity recognition and 3D thermal model
generation using thermal images, RGB images, captured from external sensors, and the …

3D shape measurement of discontinuous specular objects based on advanced PMD with bi-telecentric lens

Z Niu, N Gao, Z Zhang, F Gao, X Jiang - Optics Express, 2018 - opg.optica.org
This paper presents an advanced phase measuring deflectometry (PMD) method based on
a novel mathematical model to obtain three dimensional (3D) shape of discontinuous …

High-accuracy projector calibration method for fringe projection profilometry considering perspective transformation

J Yu, N Gao, Z Meng, Z Zhang - Optics Express, 2021 - opg.optica.org
Camera and projector are the key components of structured light three-dimensional (3-D)
measurements, and Digital Light Processing (DLP) projector has been widely used for …

Generic exponential fringe model for alleviating phase error in phase measuring profilometry

C Chen, N Gao, X Wang, Z Zhang, F Gao… - Optics and Lasers in …, 2018 - Elsevier
Phase measuring profilometry (PMP) is susceptible to phase error caused by gamma
distortion that leads to the captured fringe patterns deviating from ideal sinusoidal …

3D reconstruction method based on N-step phase unwrapping

L Wang, L Yi, Y Zhang, X Wang, W Wang, X Wang… - The Visual …, 2024 - Springer
Reducing the number of images in fringe projection profilometry has emerged as a
significant research focus. Traditional temporal phase unwrapping algorithms typically …

High sensitivity fringe projection profilometry combining optimal fringe frequency and optimal fringe direction

J Yu, N Gao, Z Zhang, Z Meng - Optics and Lasers in Engineering, 2020 - Elsevier
Phase sensitivity plays a vital role in accurately retrieving three-dimensional (3D) shape of
diffused objects in fringe projection profilometry (FPP). With regard to traditional means that …

An iterative distortion compensation algorithm for camera calibration based on phase target

Y Xu, F Gao, H Ren, Z Zhang, X Jiang - Sensors, 2017 - mdpi.com
Camera distortion is a critical factor affecting the accuracy of camera calibration. A
conventional calibration approach cannot satisfy the requirement of a measurement system …