Surface Extraction from Multi-Material Components for Metrology using Dual Energy CT

Christoph Heinzl, Johann Kastner, Meister Eduard Gröller
Surface Extraction from Multi-Material Components for Metrology using Dual Energy CT
TR-186-2-07-06, May 2007 [paper]

Information

Abstract

This paper describes a novel method for creating surface models of multi-material components using dual energy computed tomography (DECT). Application scenario for the presented work is metrology and dimensional measurement of multi-material components in industrial high resolution 3D X-Ray computed tomography (3DCT). The basis of this method is the dual source / dual exposure technology using the different X-Ray imaging modalities of a high precision micro-focus and a high energy macro-focus X-Ray source. The presented work aims at combining the advantages of both X-Ray modalities in order to facilitate dimensional measurement of multi-material components with high density material within low density material. We propose a pipeline model using image fusion and local surface extraction technologies: A prefiltering step reduces data inherent noise. For image fusion purposes the datasets have to be registered to each other. In the fusion step the benefits of each modality are combined. So the structure of the specimen is taken from the low precision, blurry, high energy dataset while the sharp edges are adopted and fused into the resulting image from the high precision, crisp, low energy dataset. In the final step a reliable surface model is calculated of the fused dataset, which locally adapts the surface model by moving surface vertices in the direction of the corresponding point normal to a position with maximum gradient magnitude. The major contribution of this paper is the development of a specific workflow for dimensional measurement of multi-material industrial components from high resolution industrial CT data. Several algorithms are extended to take two data sources with complementary strengths and weaknesses into account. The presented workflow is crucial for the following visual inspection of deviations.

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BibTeX

@techreport{TR-186-2-07-06,
  title =      "Surface Extraction from Multi-Material Components for
               Metrology using Dual Energy CT",
  author =     "Christoph Heinzl and Johann Kastner and Meister Eduard
               Gr\"{o}ller",
  year =       "2007",
  abstract =   "This paper describes a novel method for creating surface
               models of multi-material components using dual energy
               computed tomography (DECT). Application scenario for the
               presented work is metrology and dimensional measurement of
               multi-material components in industrial high resolution 3D
               X-Ray computed tomography (3DCT). The basis of this method
               is the dual source / dual exposure technology using the
               different X-Ray imaging modalities of a high precision
               micro-focus and a high energy macro-focus X-Ray source. The
               presented work aims at combining the advantages of both
               X-Ray modalities in order to facilitate dimensional
               measurement of multi-material components with high density
               material within low density material. We propose a pipeline
               model using image fusion and local surface extraction
               technologies: A prefiltering step reduces data inherent
               noise. For image fusion purposes the datasets have to be
               registered to each other. In the fusion step the benefits of
               each modality are combined. So the structure of the specimen
               is taken from the low precision, blurry, high energy dataset
               while the sharp edges are adopted and fused into the
               resulting image from the high precision, crisp, low energy
               dataset. In the final step a reliable surface model is
               calculated of the fused dataset, which locally adapts the
               surface model by moving surface vertices in the direction of
               the corresponding point normal to a position with maximum
               gradient magnitude. The major contribution of this paper is
               the development of a specific workflow for dimensional
               measurement of multi-material industrial components from
               high resolution industrial CT data. Several algorithms are
               extended to take two data sources with complementary
               strengths and weaknesses into account. The presented
               workflow is crucial for the following visual inspection of
               deviations.",
  month =      may,
  number =     "TR-186-2-07-06",
  address =    "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria",
  institution = "Institute of Computer Graphics and Algorithms, Vienna
               University of Technology ",
  note =       "human contact: technical-report@cg.tuwien.ac.at",
  keywords =   "DECT image fusion, local surface extraction, metrology, Dual
               Energy CT, dimensional measurement, variance comparison",
  URL =        "https://www.cg.tuwien.ac.at/research/publications/2007/TR-186-2-07-06/",
}