Authors:	Khan, F. Enzmann, Frieder Kersten, Michael
Title:	Beam-hardening correction by a surface fitting and phase classification by a least square support vector machine approach for tomography images of geological samples
Online publication date:	12-Jul-2022
Year of first publication:	2015
Language:	english
Abstract:	In X-ray computed microtomography (μXCT) image processing is the most important operation prior to image analysis. Such processing mainly involves artefact reduction and image segmentation. We propose a new two-stage post-reconstruction procedure of an image of a geological rock core obtained by polychromatic cone-beam μXCT technology. In the first stage, the beam-hardening (BH) is removed applying a best-fit quadratic surface algorithm to a given image data set (reconstructed slice), which minimizes the BH offsets of the attenuation data points from that surface. The final BH-corrected image is extracted from the residual data, or the difference between the surface elevation values and the original grey-scale values. For the second stage, we propose using a least square support vector machine (a non-linear classifier algorithm) to segment the BH-corrected data as a pixel-based multi-classification task. A combination of the two approaches was used to classify a complex multi-mineral rock sample. The Matlab code for this approach is provided in the Appendix. A minor drawback is that the proposed segmentation algorithm may become computationally demanding in the case of a high dimensional training data set.
DDC:	550 Geowissenschaften 550 Earth sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 09 Chemie, Pharmazie u. Geowissensch.
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-7371
Version:	Published version
Publication type:	Zeitschriftenaufsatz
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/3.0/
Journal:	Solid earth discussions 7 4
Pages or article number:	3383 3408
Publisher:	Copernicus Publ.
Publisher place:	Göttingen
Issue date:	2015
ISSN:	1869-9537
Publisher URL:	http://dx.doi.org/10.5194/sed-7-3383-2015
Publisher DOI:	10.5194/sed-7-3383-2015
Appears in collections:	DFG-OA-Publizieren (2012 - 2017)