Assessing Geometric Calibration Algorithms for the ODIN X-ray Setup at the European Spallation Source
(2025) In TFHF-5000 FHLM01 20251Solid Mechanics
Department of Construction Sciences
- Abstract
- ODIN (Optical and Diffraction Imaging with Neutrons) is a general purpose imaging in-
strument under construction at the European Spallation Source (ESS). The instrument
will provide the scientific community with a wide array of neutron imaging techniques,
including neutron tomography. Coupled with an integrated X-ray source, the instrument
will feature multi-modal capabilities. The complementary nature of X-rays and neutrons
enables the capture of a wider range of physical phenomena than the separate techniques
can provide independently, such as both structure and moisture concentration.
Cone-beam X-ray sources, the type of source planned for use in ODIN, require calibration
to account for the diverging beam geometry produced by... (More) - ODIN (Optical and Diffraction Imaging with Neutrons) is a general purpose imaging in-
strument under construction at the European Spallation Source (ESS). The instrument
will provide the scientific community with a wide array of neutron imaging techniques,
including neutron tomography. Coupled with an integrated X-ray source, the instrument
will feature multi-modal capabilities. The complementary nature of X-rays and neutrons
enables the capture of a wider range of physical phenomena than the separate techniques
can provide independently, such as both structure and moisture concentration.
Cone-beam X-ray sources, the type of source planned for use in ODIN, require calibration
to account for the diverging beam geometry produced by a point source. Lack of proper
geometric calibration of the X-ray tomography setup can deteriorate the quality of the to-
mographic reconstruction, introducing artifacts and lowering the image contrast. Multiple
calibration approaches have been put forward, primarily from the medical CT community,
to perform geometric calibration aided by a well-defined calibration “phantom”.
This thesis evaluates two common approaches for geometric calibration found in the lit-
erature, nonlinear optimization and elliptical fitting, as well as presenting a novel im-
plementation of the former based on genetic algorithms. The evaluation was performed
on calibration and sample datasets scanned with an off-the-shelf X-ray tomography sys-
tem, which served as the reference. Furthermore, three pieces of reconstruction software,
Muhrec, CIL and XAct were coupled with the produced geometric calibration sets to fur-
ther evaluate the algorithms, based on the reconstruction results of the scanned samples.
Each implementation was capable of producing accurate estimates of the parameters, with
the elliptical fitting approach yielding the most precise and robust. However, the methods
utilizing numerical optimization fared better in terms of reconstruction quality. Each of
the evaluated reconstruction software packages were able to produce high quality recon-
structions, but XAct and CIL exhibited increased consistency in terms of performance.
The robustness of the elliptical fitting approach would make it suitable for the instrument
environment of ODIN, but each approach has its strengths and there is no clear choice based
on the results achieved. This thesis has laid the groundwork for further evaluation of the
proposed methods, as well as studies into potential two-step and end-to-end reconstruction-
coupled calibration techniques. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9212673
- author
- Linder, Joelle LU
- supervisor
- organization
- course
- FHLM01 20251
- year
- 2025
- type
- H3 - Professional qualifications (4 Years - )
- subject
- keywords
- european spallation source, neutron science, tomography, geometric calibration, cbct, xray-tomography, dual-modality imaging, ODIN, genetic algorithms, levenberg marquardt
- publication/series
- TFHF-5000
- report number
- TFHF-5270
- other publication id
- LUTFD2/TFHF-25/5270-SE(1-63)
- language
- English
- id
- 9212673
- date added to LUP
- 2025-10-14 09:54:16
- date last changed
- 2025-10-14 09:54:16
@misc{9212673,
abstract = {{ODIN (Optical and Diffraction Imaging with Neutrons) is a general purpose imaging in-
strument under construction at the European Spallation Source (ESS). The instrument
will provide the scientific community with a wide array of neutron imaging techniques,
including neutron tomography. Coupled with an integrated X-ray source, the instrument
will feature multi-modal capabilities. The complementary nature of X-rays and neutrons
enables the capture of a wider range of physical phenomena than the separate techniques
can provide independently, such as both structure and moisture concentration.
Cone-beam X-ray sources, the type of source planned for use in ODIN, require calibration
to account for the diverging beam geometry produced by a point source. Lack of proper
geometric calibration of the X-ray tomography setup can deteriorate the quality of the to-
mographic reconstruction, introducing artifacts and lowering the image contrast. Multiple
calibration approaches have been put forward, primarily from the medical CT community,
to perform geometric calibration aided by a well-defined calibration “phantom”.
This thesis evaluates two common approaches for geometric calibration found in the lit-
erature, nonlinear optimization and elliptical fitting, as well as presenting a novel im-
plementation of the former based on genetic algorithms. The evaluation was performed
on calibration and sample datasets scanned with an off-the-shelf X-ray tomography sys-
tem, which served as the reference. Furthermore, three pieces of reconstruction software,
Muhrec, CIL and XAct were coupled with the produced geometric calibration sets to fur-
ther evaluate the algorithms, based on the reconstruction results of the scanned samples.
Each implementation was capable of producing accurate estimates of the parameters, with
the elliptical fitting approach yielding the most precise and robust. However, the methods
utilizing numerical optimization fared better in terms of reconstruction quality. Each of
the evaluated reconstruction software packages were able to produce high quality recon-
structions, but XAct and CIL exhibited increased consistency in terms of performance.
The robustness of the elliptical fitting approach would make it suitable for the instrument
environment of ODIN, but each approach has its strengths and there is no clear choice based
on the results achieved. This thesis has laid the groundwork for further evaluation of the
proposed methods, as well as studies into potential two-step and end-to-end reconstruction-
coupled calibration techniques.}},
author = {{Linder, Joelle}},
language = {{eng}},
note = {{Student Paper}},
series = {{TFHF-5000}},
title = {{Assessing Geometric Calibration Algorithms for the ODIN X-ray Setup at the European Spallation Source}},
year = {{2025}},
}