Spatio-temporal image-based water surface reconstruction: Application to sloshing in navigation lock filling
Engelen, L. (2016). Spatio-temporal image-based water surface reconstruction: Application to sloshing in navigation lock filling. MSc Thesis. Ghent University, Department of Civil Engineering: Ghent. 170 pp.
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| Beschikbaar in | Auteur |
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Documenttype: Doctoraat/Thesis/Eindwerk
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| Author keywords |
Image-based reconstruction; Shape from refractive distortion; 3D shape acquisition of water; Surface parameterization; Feature tracking |
| Abstract |
During this master dissertation, we present a novel, image-based methodology to obtain a spatiotemporal description of a dynamically changing water surface. The method combines a shape from refractive distortion approach with prior knowledge about the expected surface shape. To that end, we derive a parameterized model that for each time instance is fitted to describe the instantaneous surface shape.The developed algorithm is validated by means of experimental tests as well as with numerical simulations. The results prove that we are able to reconstruct the three-dimensional shape of the water surface with sub-millimeter accuracy. Additionally, we conducted an extensive error assessment to obtain insight in how the accuracy and robustness of the algorithm can be maximized. The method is finally extended with an optical flow method to track distinctive features across images, which allows highly time-efficient processing of image sequences or videos. A first test case is presented, consisting of the filling process of a rectangular basin, which shows that the time-dependent three-dimensional shape of a fluctuating water surface can be reconstructed. The temporal resolution was however too small to obtain accurate quantitative results. Provided that the experimental setup is improved, it can be assumed that the developed algorithm can be used to study numerous hydrodynamic phenomena. |
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