| 1. |
- Bigun, Josef, 1961-, et al.
(författare)
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Multimodal biometric authentication using quality signals in mobile communications
- 2003
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Ingår i: Proceedings - 12th International Conference on Image Analysis and Processing, ICIAP 2003. - Los Alamitos, USA : IEEE Computer Society. - 0769519482 ; , s. 2-11
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The elements of multimodal authentication along with system models are presented. These include the machine experts as well as machine supervisors. In particular fingerprint and speech based systems will serve as illustration of a mobile authentication application. A novel signal adaptive supervisor, based on the input biometric signal quality is evaluated. Experimental results on data collected from mobile telephones are reported demonstrating the benefits of the proposed scheme. © 2003 IEEE.
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| 2. |
- Bigun, Josef, et al.
(författare)
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Orientation fields filtering by derivates of a Gaussian
- 2003
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Ingår i: Image Analysis. - Berlin : Springer. - 3540406018 ; , s. 307-313, s. 19-27
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Bokkapitel (refereegranskat)abstract
- We suggest a set of complex differential operators, symmetry derivatives, that can be used for matching and pattern recognition. We present results on the invariance properties of these. These show that all orders of symmetry derivatives of Gaussians yield a remarkable invariance : they are obtained by replacing the original differential polynomial with the same polynomial but using ordinary scalars. Moreover, these functions are closed under convolution and they are invariant to the Fourier transform. The revealed properties have practical consequences for local orientation based feature extraction. This is shown by two applications: i) tracking markers in vehicle tests ii) alignment of fingerprints.
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| 3. |
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| 4. |
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Image analysis : 13th Scandinavian Conference, SCIA 2003, Halmstad, Sweden, June 29-July 2, 2003, Proceedings
- 2003
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Proceedings (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- This book constitutes the refeered proceedings of the 13th Scandinavian Conference on Image Analysis, SCIA 2003, held in Halmstad, Sweden in June/July 2003.The 148 revised full papers presented together with 6 invited contributions were carefully reviewed and selected for presentation. The papers are organized in topical sections on feature extraction, depth and surface, shape analysis, coding and representation, motion analysis, medical image processing, color analysis, texture analysis, indexing and categorization, and segmentation and spatial grouping.
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| 5. |
- Nilsson, Kenneth, 1951-, et al.
(författare)
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Localization of corresponding points in fingerprints by complex filtering
- 2003
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Ingår i: Pattern Recognition Letters. - Amsterdam : Elsevier. - 0167-8655 .- 1872-7344. ; 24:13, s. 2135-2144
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Tidskriftsartikel (refereegranskat)abstract
- For the alignment of two fingerprints certain landmark points are needed. These should be automaticaly extracted with low misidentification rate. As landmarks we suggest the prominent symmetry points (singular points, SPs) in the fingerprints. We identify an SP by its symmetry properties. SPs are extracted from the complex orientation field estimated from the global structure of the fingerprint, i.e. the overall pattern of the ridges and valleys. Complex filters, applied to the orientation field in multiple resolution scales, are used to detect the symmetry and the type of symmetry. Experimental results are reported.
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| 6. |
- Persson, Martin, et al.
(författare)
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Protein spot detection by symmetry derivatives of Gaussians
- 2003
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Ingår i: Image analysis, 13th Scandinavian Conference, SCIA 2003, Halmstad, Sweden, June 29 - July 2, 2003, Proceedings. - : Springer. - 9783540406013 ; , s. 520-525
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Konferensbidrag (refereegranskat)abstract
- Two-dimensional gel electrophoresis is the preferred method for simultaneously separating and visualising thousands of proteins. An important part of the computer aided analysis of the proteome is the ability to automatically detect, identify, and quantify the proteins by means of automatic Image processing. We present a fast and sensitive method for protein spot detection using the Circular Symmetry Tensor. It is based upon the work of Bigun on Symmetry derivatives of Gaussians.
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| 7. |
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| 8. |
- Thärnå, Johan, et al.
(författare)
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Orientation scanning to improve lossless compression of fingerprint images
- 2003
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Ingår i: Audio-and video-based biometric person authentication. - Berlin. - 3540403027 ; , s. 343-350
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- While standard compression methods available include complex source encoding schemes, the scanning of the image is often performed by a horizontal (row-by-row) or vertical scanning. In this work a new scanning method, called ridge scanning, for lossless compression of fingerprint images is presented. By using ridge scanning our goal is to increase the redundancy in data and thereby increase the compression rate. By using orientations, estimated from the linear symmetry property of local neighbourhoods in the fingerprint, a scanning algorithm which follows the ridges and valleys is developed. The properties of linear symmetry are also used for a segmentation of the fingerprint into two parts, one part which lacks orientation and one that has it. We demonstrate that ridge scanning increases the compression ratio for Lempel-Ziv coding as well as recursive Huffman coding with approximately 3% in average. Compared to JPEG-LS, using ridge scanning and recursive Huffman the gain is 10% in average.
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