| 1. |
- Aanaes, H, et al.
(författare)
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Robust factorization
- 2002
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Ingår i: IEEE Transactions on Pattern Analysis and Machine Intelligence. - 1939-3539. ; 24:9, s. 1215-1225
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Tidskriftsartikel (refereegranskat)abstract
- Factorization algorithms for recovering structure and motion from an image stream have many advantages, but they usually require a set of well-tracked features. Such a set is in generally not available in practical applications. There is thus a need for making factorization algorithms deal effectively with errors in the tracked features. We propose a new and computationally efficient algorithm for applying an arbitrary errorfunction in the factorization scheme. This algorithm enables the use of robust statistical techniques and arbitrary noise models for the individual features. These techniques and models enable the factorization scheme to deal effectively with mismatched features, missing features, and noise on the individual features. The proposed approach further includes a new method for Euclidean reconstruction that significantly improves convergence of the factorization algorithms. The proposed algorithm has been implemented as a modification of the Christy-Horaud factorization scheme, which yields a perspective reconstruction. Based on this implementation, a considerable increase in error tolerance is demonstrated on real and synthetic data. The proposed scheme can, however, be applied to most other factorization algorithms.
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| 2. |
- Aanaes, K, et al.
(författare)
-
Extensive Endoscopic Image-Guided Sinus Surgery Decreases BPI-ANCA in Patients with Cystic Fibrosis
- 2012
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Ingår i: Scandinavian Journal of Immunology. - : Blackwell Publishing. - 0300-9475 .- 1365-3083. ; 76:6, s. 573-579
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Tidskriftsartikel (refereegranskat)abstract
- Antineutrophil cytoplasm autoantibodies (ANCA) directed against bactericidal/permeability-increasing protein (BPI) are common in patients with cystic fibrosis (CF), and serum levels are correlated with lung colonization by Pseudomonas aeruginosa and the severity of lung damage. The production of BPI-ANCA may be due to the costimulation of BPI when mounting an immune response against P. aeruginosa. The effect of surgery aiming to eradicate bacteria and infected tissue on BPI-ANCA levels is sparsely described. A cohort of patients with CF were included: 53 patients having extensive image-guided sinus surgery (EIGSS) with topical postoperative antibiotic treatment, 131 non-operated controls and 36 who had double lung transplantation (LTX). In all 219 patients, serum samples before and after surgery or at similar intervals were analysed for IgG and IgA BPI-ANCA. The EIGSS group showed a highly significant decrease in both IgA and IgG BPI-ANCA levels compared with their own preoperative values and control group values (P andlt; 0.0010.02). The LTX patients also showed a highly significant decrease in both IgA and IgG BPI-ANCA levels (P andlt; 0.001). EIGSS and LTX decrease IgA and IgG BPI-ANCA levels in patients with CF, indicating that extensive removal of infected tissue influences the pathogenic process of autoantibody production. The results shown herein are in favour of applying EIGSS in selected patients with CF and for using BPI-ANCA as a surrogate marker for guiding further therapeutic interventions.
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| 3. |
- Svensson, Charlotte, et al.
(författare)
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Structure estimation and surface triangulation of deformable objects
- 2003
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Ingår i: Lecture Notes in Computer Science (Image Analysis, Proceedings). - 0302-9743 .- 1611-3349. - 9783540406013 ; 2749, s. 709-716
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Konferensbidrag (refereegranskat)abstract
- A system is developed that from an image sequence of a deformable object automatically extracts features and tracks them through the sequence, estimates the non-rigid 3D structure and finally computes a surface triangulation. Also the camera motion is acquired. The object is supposed to deform according to a linear model, while the motion of the camera can be arbitrary. No domain specific prior of the object is required. For the structure estimation a two-step approach is used, where we first obtain an initial estimate of the structure and motion, and then obtain an optimal solution via a non-linear optimization scheme. The triangulation is optimized to yield a non-rigid faceted surface that well approximates the true 3D surface.
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