| 61. |
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| 62. |
- Wernersson, Erik, 1984-, et al.
(författare)
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Generating synthetic μCT images of wood fibre materials
- 2009
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Ingår i: Proc. 6th International Symposium on Image and Signal Processing and Analysis. - Piscataway, NJ : IEEE. - 9789531841351 ; , s. 365-370
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Konferensbidrag (refereegranskat)abstract
- X-ray Computerized Tomography at micrometer resolution (μCT) is an important tool for understanding the properties of wood fibre materials such as paper, carton and wood fibre composites. While many image analysis methods have been developed for μCT images in wood science, the evaluation of these methods if often not thorough enough because of the lack of a dataset with ground truth. This paper describes the generation of synthetic μCT volumes of wood fibre materials. Fibres with a high degree of morphological variations are modeled and densely packed into a volume of the material. Using a simulation of the μCT image acquisition process, realistic synthetic images are obtained. This simulation uses noise characterized from a set of μCT images. The synthetic images have a known ground truth, and can therefore be used when evaluating image analysis methods.
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| 63. |
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| 64. |
- Wernersson, Erik L. G., et al.
(författare)
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Postprocessing method for reducing phase effects in reconstructed microcomputed-tomography data
- 2013
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Ingår i: Optical Society of America. Journal A. - 1084-7529 .- 1520-8532. ; 30:3, s. 455-461
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Tidskriftsartikel (refereegranskat)abstract
- With increased resolution in x-ray computed tomography, refraction adds increasingly to the attenuation signal. Though potentially beneficial, the artifacts caused by refraction often need to be removed from the image. In this paper, we propose a postprocessing method, based on deconvolution, that is able to remove these artifacts after conventional reconstruction. This method poses two advantages over existing projection-based (preprocessing) phase-retrieval or phase-removal algorithms. First, evaluation of the parameters can be done very quickly, improving the overall speed of the method. Second, postprocessing methods can be applied when projection data is not available, which occurs in several commercial systems with closed software or when projection data has been deleted. It is shown that the proposed method performs comparably to state-of-the-art methods in terms of image quality.
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| 65. |
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| 66. |
- Wernersson, Erik, 1984-, et al.
(författare)
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Segmentation of Wood Fibres in 3D CT Images Using Graph Cuts
- 2009
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Ingår i: Image Analysis and Processing – ICIAP 2009. - Berlin : Springer-Verlag. - 9783642041457 ; 5716, s. 92-102
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Konferensbidrag (refereegranskat)abstract
- To completely segment all individual wood fibres in volume images of fibrous materials presents a challenging problem but is important in understanding the micro mechanical properties of composite materials. This paper presents a filter that identifies and closes pores in wood fibre walls, simplifying the shape of the fibres. After this filter, a novel segmentation method based on graph cuts identifies individual fibres. The methods are validated on a realistic synthetic fibre data set and then applied on μCT images of wood fibre composites.
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| 67. |
- Wernersson, Erik, et al.
(författare)
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Swelling of cellulose fibres in composite materials: Constraint effects of the surrounding matrix
- 2013
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Ingår i: Composites Science and Technology. - : Elsevier BV. - 0266-3538 .- 1879-1050. ; 74, s. 52-59
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Tidskriftsartikel (refereegranskat)abstract
- Wood fibres have several highly desirable properties as reinforcement in composite materials for structural applications, e.g. high specific stiffness and strength, renewability and low cost. However, one of the main drawbacks is the swelling of these hydrophilic fibres due to moisture uptake. Since the fibres in the composite are generally embedded in a relatively hydrophobic matrix, the surrounding matrix should restrain the swelling of the fibres. The present study investigates this constraint effect and establishes a micromechanical model to predict the swelling of embedded fibres based on experimentally characterised microstructural parameters and hygroelastic properties of the constituents. The predicted swelling is in concert with direct measurement of various wood-pulp fibre composites by means of three-dimensional X-ray microtomographic images. (c) 2012 Elsevier Ltd. All rights reserved.
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