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Norell, Kristin
##### Publications (8 of 8) Show all publications
Norell, K. (2011). Automatic counting of annual rings on Pinus sylvestris end faces in sawmill industry. Computers and Electronics in Agriculture, 75(2), 231-237
Open this publication in new window or tab >>Automatic counting of annual rings on Pinus sylvestris end faces in sawmill industry
2011 (English)In: Computers and Electronics in Agriculture, ISSN 0168-1699, E-ISSN 1872-7107, Vol. 75, no 2, p. 231-237Article in journal (Refereed) Published
##### National Category
Computer Vision and Robotics (Autonomous Systems)
##### Identifiers
urn:nbn:se:uu:diva-125242 (URN)10.1016/j.compag.2010.11.005 (DOI)000287952500002 ()
Available from: 2010-05-12 Created: 2010-05-12 Last updated: 2018-01-12Bibliographically approved
Norell, K. (2009). An automatic method for counting annual rings in noisy sawmill images. In: Image Analysis and Processing – ICIAP 2009 (pp. 307-316). Springer Berlin / Heidelberg
Open this publication in new window or tab >>An automatic method for counting annual rings in noisy sawmill images
2009 (English)In: Image Analysis and Processing – ICIAP 2009, Springer Berlin / Heidelberg , 2009, p. 307-316Conference paper, Published paper (Refereed)
##### Abstract [en]

The annual ring pattern of a log end face is related to the quality of the wood. We propose a method for computing the number of annual rings on a log end face depicted in sawmill production. The method is based on the grey-weighted polar distance transform and registration of detected rings from two different directions. The method is developed and evaluated on noisy images captured in on-line sawmill production at a Swedish sawmill during 2008, using an industrial colour camera. We have also evaluated the method using synthetic data with different ring widths, ring eccentricity, and noise levels.

##### Place, publisher, year, edition, pages
Springer Berlin / Heidelberg, 2009
##### Series
Lecture Notes in Computer Science, ISSN 0302-9743 ; 5716
##### National Category
Computer Vision and Robotics (Autonomous Systems)
##### Research subject
Computerized Image Analysis
##### Identifiers
urn:nbn:se:uu:diva-108590 (URN)10.1007/978-3-642-04146-4_34 (DOI)978-3-642-04145-7 (ISBN)
Available from: 2009-09-23 Created: 2009-09-23 Last updated: 2018-01-13Bibliographically approved
Norell, K. (2009). Creating synthetic log end face images. In: P. Zinterhof; S. Loncaric; A. Uhl; A.Carini (Ed.), Proceedings of 6th International Symposium on Image and Signal Processing and Analysis, 2009.: ISPA 2009.. Paper presented at 6th International Symposium on Image and Signal Processing and Analysis (pp. 353-358).
Open this publication in new window or tab >>Creating synthetic log end face images
2009 (English)In: Proceedings of 6th International Symposium on Image and Signal Processing and Analysis, 2009.: ISPA 2009. / [ed] P. Zinterhof; S. Loncaric; A. Uhl; A.Carini, 2009, p. 353-358Conference paper, Published paper (Refereed)
##### Abstract [en]

In this paper we present the design and creation of synthetic images of log end faces. The images are constructed to resemble images of Scots pine taken in on-line sawmill production. Wood features such as knots, heartwood, and annual rings, as well as the sawing procedure, storage, and imaging, including camera position, are simulated. A dataset of 100 images is provided, together with code for generating new synthetic data.

##### National Category
Computer Vision and Robotics (Autonomous Systems)
##### Research subject
Computerized Image Analysis
##### Identifiers
urn:nbn:se:uu:diva-111218 (URN)978-953-184-135-1 (ISBN)
##### Conference
6th International Symposium on Image and Signal Processing and Analysis
Available from: 2009-12-07 Created: 2009-12-07 Last updated: 2018-01-12Bibliographically approved
Bengtsson, E., Norell, K., Nyström, I., Strand, R. & Wadelius, L. (2008). Annual Report 2007.
Open this publication in new window or tab >>Annual Report 2007
2008 (English)Report (Other (popular science, discussion, etc.))
p. 77
##### National Category
Engineering and Technology
##### Identifiers
urn:nbn:se:uu:diva-16167 (URN)
Available from: 2008-05-08 Created: 2008-05-08 Last updated: 2017-02-08Bibliographically approved
Norell, K. & Borgefors, G. (2008). Estimation of pith position in untreated log ends in sawmill environments. Computers and Electronics in Agriculture, 63(2), 155-167
Open this publication in new window or tab >>Estimation of pith position in untreated log ends in sawmill environments
2008 (English)In: Computers and Electronics in Agriculture, ISSN 0168-1699, E-ISSN 1872-7107, Vol. 63, no 2, p. 155-167Article in journal (Refereed) Published
##### Abstract [en]

Two related methods for automatic estimation of the pith position, i.e., the centre of the annual rings, in wood log end face images are presented. We use images that depict untreated log end faces that are deliberately chosen to include difficulties such as rot, non-circular shape, uncentered pith and dirt. The images are taken with a regular digital camera in sawmill environments. Both presented methods use local orientation and Hough transform to detect the pith position, but two different ways to compute the local orientation are used. The results are promising for both methods. At least one of the methods is fast enough to use on-line at a sawmill.

##### Keywords
Image processing, Orientation estimation, Rotation filter, Quadrature filters, Laplacian pyramid, Annual rings
##### National Category
Agricultural Sciences
##### Research subject
Computerized Image Analysis
##### Identifiers
urn:nbn:se:uu:diva-88064 (URN)10.1016/j.compag.2008.02.006 (DOI)000258367600008 ()
Available from: 2009-01-19 Created: 2009-01-19 Last updated: 2017-12-14Bibliographically approved
Norell, K. & Lindblad, J. (2008). Spatially-variant morphological operations on binary images based on the polar distance transform. In: ICPR 2008: . Paper presented at Proceedings of 19th International Conference on Pattern Recognition (ICPR 2008), Tampa, Florida, December 2008. IEEE computer society
Open this publication in new window or tab >>Spatially-variant morphological operations on binary images based on the polar distance transform
2008 (English)In: ICPR 2008, IEEE computer society , 2008Conference paper, Published paper (Refereed)
##### Abstract [en]

Binary mathematical morphology can be computed by thresholding a distance transform, provided that the distance transform is a metric. Here we show that the polar distance transform is a metric and use it for morphological operations. The polar distance transform varies with the spatial coordinates of the image, resulting in spatially-variant morphology. In this distance transform each pixel is related to an image origin. We prefer angular propagation over radial, thus we construct structuring elements that are elongated in the angular direction, which is useful when circular segments are handled. We show an example where segments of annual rings on a log end face are connected using mathematical morphology based on the polar distance transform.

##### Place, publisher, year, edition, pages
IEEE computer society, 2008
##### Series
IEEE Proceedings, ISSN 1051-4651 ; CFP08182
##### National Category
Discrete Mathematics
##### Research subject
Computerized Image Analysis
##### Identifiers
urn:nbn:se:uu:diva-88066 (URN)978-1-4244-2175-6 (ISBN)
##### Conference
Proceedings of 19th International Conference on Pattern Recognition (ICPR 2008), Tampa, Florida, December 2008
Available from: 2009-01-19 Created: 2009-01-19 Last updated: 2018-12-18
Norell, K., Lindblad, J. & Svensson, S. (2008). The polar distance transform. In: Proceedings SSBA 2008, Symposium on image analysis, Lund.
Open this publication in new window or tab >>The polar distance transform
2008 (English)In: Proceedings SSBA 2008, Symposium on image analysis, Lund, 2008Conference paper, Published paper (Other academic)
##### Research subject
Computerized Image Analysis
##### Identifiers
urn:nbn:se:uu:diva-88065 (URN)
Available from: 2009-01-19 Created: 2009-01-19 Last updated: 2018-12-02Bibliographically approved
Norell, K., Lindblad, J. & Svensson, S. (2007). Grey Weighted Polar Distance Transform for Outlining Circular and Approximately Circular Objects. In: 14th International Conference on Image Analysis and Processing: ICIAP 2007 (pp. 647-652).
Open this publication in new window or tab >>Grey Weighted Polar Distance Transform for Outlining Circular and Approximately Circular Objects
2007 (English)In: 14th International Conference on Image Analysis and Processing: ICIAP 2007, 2007, p. 647-652Conference paper, Published paper (Refereed)
##### Abstract [en]

We introduce the polar distance transform and the grey weighted polar distance transform for computation of minimum cost paths preferring circular shape, as well as give algorithms for implementations in a digital setting. An alternative to the polar distance transform is to transform the image to polar coordinates, and then apply a Cartesian distance transform. By using the polar distance transform, re-sampling of the image and interpolation of new pixel values are avoided. We also handle the case of grey weighted distance transform in a $5\times 5$ neighbourhood, which, to our knowledge, is new. Initial results of using the grey weighted polar distance transform to outline annual rings in images of log end faces are presented.

##### National Category
Computer Vision and Robotics (Autonomous Systems)
##### Identifiers
urn:nbn:se:uu:diva-12282 (URN)10.1109/ICIAP.2007.74 (DOI)0-7695-2877-5 (ISBN)
Available from: 2007-12-10 Created: 2007-12-10 Last updated: 2018-08-24Bibliographically approved

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