Distance Calibration between Reference Plane and Screen in Direct Phase Measuring Deflectometry
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2018-01-06 |
| Journal | Sensors |
| Authors | Shujun Huang, Yue Liu, Nan Gao, Zonghua Zhang, Feng Gao |
| Institutions | University of Huddersfield, Hebei University of Technology |
| Citations | 14 |
Abstract
Section titled âAbstractâThe recently developed direct phase measuring deflectometry (DPMD) method can directly measure the three-dimensional (3D) shape of specular objects with discontinuous surfaces, but requires a calibrated distance between a reference plane and liquid crystal display screen. Because the plane and screen are different distances from the imaging device, they cannot be clearly captured given the limited depth of field (DOF) of the lens. Therefore, existing machine vision-based methods cannot be used to effectively calibrate a DPMD system. In this paper, a new distance calibration method that uses a mirror with a hollow ring matrix pattern and a mobile stage is presented. The direction of the mobile stage in the camera coordinate system is determined by the mirrorâs pattern at several positions in the cameraâs DOF so that the reference position outside of the DOF can be calculated. The screenâs position can also be calibrated by displaying patterns at a known scale. Therefore, the required distance is accurately obtained in the camera coordinate system. Evaluation results show that the maximum value of the absolute error is less than 0.031 mm. The experimental results on an artificial stepped mirror and a reflected diamond distribution surface demonstrate the accuracy and practicality of the proposed method.
Tech Support
Section titled âTech SupportâOriginal Source
Section titled âOriginal SourceâReferences
Section titled âReferencesâ- 2012 - An absolute phase technique for 3D profile measurement using four-step structured light pattern [Crossref]
- 2012 - High-speed three-dimensional profilometry for multiple objects with complex shapes [Crossref]
- 2016 - Structured light field 3D imaging [Crossref]
- 2016 - Temporal phase unwrapping algorithms for fringe projection profilometry: A comparative review [Crossref]
- 2012 - Strategy for automatic and complete three-dimensional optical digitization [Crossref]
- 2004 - Phase measuring deflectometry: A new approach to measure specular free-form surfaces [Crossref]
- 2016 - Modal phase measuring deflectometry [Crossref]
- 2008 - Reflective fringe pattern technique for subsurface crack detection [Crossref]
- 2008 - MicrodeflectometryâA novel tool to acquire three-dimensional microtopography with nanometer height resolution [Crossref]
- 2012 - 3D shape reconstruction of large specular surface [Crossref]