TY  - JOUR
AV  - public
SP  - 1101
EP  - 1117
A1  - Chadebecq, F
A1  - Vasconcelos, F
A1  - Lacher, R
A1  - Maneas, E
A1  - Desjardins, A
A1  - Ourselin, S
A1  - Vercauteren, T
A1  - Stoyanov, D
KW  - Underwater imaging · Two-view Refractive Structure-from-Motion · Flat refractive geometry
N2  - Recovering 3D geometry from cameras in underwater applications involves the Refractive Structure-from-Motion problem
where the non-linear distortion of light induced by a change of medium density invalidates the single viewpoint assumption.
The pinhole-plus-distortion camera projection model suffers from a systematic geometric bias since refractive distortion
depends on object distance. This leads to inaccurate camera pose and 3D shape estimation. To account for refraction, it is
possible to use the axial camera model or to explicitly consider one or multiple parallel refractive interfaces whose orientations
and positions with respect to the camera can be calibrated. Although it has been demonstrated that the refractive camera model
is well-suited for underwater imaging, Refractive Structure-from-Motion remains particularly difficult to use in practice when
considering the seldom studied case of a camera with a flat refractive interface. Our method applies to the case of underwater
imaging systems whose entrance lens is in direct contact with the external medium. By adopting the refractive camera model,
we provide a succinct derivation and expression for the refractive fundamental matrix and use this as the basis for a novel twoview reconstruction method for underwater imaging. For validation we use synthetic data to show the numerical properties
of our method and we provide results on real data to demonstrate its practical application within laboratory settings and for
medical applications in fluid-immersed endoscopy. We demonstrate our approach outperforms classic two-view Structurefrom-Motion method relying on the pinhole-plus-distortion camera model.
JF  - International Journal of Computer Vision
VL  - 128
TI  - Refractive Two-View Reconstruction for Underwater 3D Vision
N1  - This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
ID  - discovery10087819
UR  - https://doi.org/10.1007/s11263-019-01218-9
Y1  - 2020///
ER  -