University of Twente Student Theses
Solving ambiguity problems in phase based profilometry
Schippers, E. (2010) Solving ambiguity problems in phase based profilometry.
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Abstract: | This report is the result of a master thesis assignment at the Signals and Systems Group, University of Twente. Half of this project focuses on the creation of a development platform, which can be used for research on structured light systems. In the other half the platform is used to experimentally test a structured light approach called phase based profilometry. The platform hardware was already available at the start of the project and consists of a digital projector, a digital photo camera and a stable rig. In this assignment, software was developed to enable accurate calibration of the devices, both geometrically and radiometrically. The software is created as a Matlab toolbox. In phase based profilometry a projector is used to spatially modulate a light source with a periodic function. This light is used to illuminate an object of interest of which the 3D structure is required. Depending on the nature of the projected function, the phase of the function can be estimated by observing the object with a camera and analysing the deformed and shifted patterns. This project concludes with the unambiguous 3D reconstruction of a scene at a distance of 1 meter with a 2mm standard deviation in depth, using two projections of a high frequency sine wave. The frequency has a low component in the phase direction (comparable with the epipolar line in stereo imaging). Due to this component, the distance between ambiguous solutions can be kept large. Thanks to fact that the component in the orthogonal direction is high, basic phase estimation schemes can still function properly. |
Item Type: | Essay (Master) |
Faculty: | EEMCS: Electrical Engineering, Mathematics and Computer Science |
Subject: | 53 electrotechnology |
Programme: | Electrical Engineering MSc (60353) |
Link to this item: | https://purl.utwente.nl/essays/68944 |
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