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• 245 Articles de conférence

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245 Articles de conférence

41 - High resolution SAR-image classification by Markov random fields and finite mixtures. G. Moser et V. Krylov et S.B. Serpico et J. Zerubia. Dans Proc. of SPIE (IS&T/SPIE Electronic Imaging 2010), Vol. 7533, pages 753308, San Jose, USA, janvier 2010. Mots-clés : SAR image classification, Dictionnaire, amplitude probability density, EM Stochastique (SEM), Markov random field, copula. Copyright : SPIE @INPROCEEDINGS{moserSPIE2010a, author = {Moser, G. and Krylov, V. and Serpico, S.B. and Zerubia, J.}, title = {High resolution SAR-image classification by Markov random fields and finite mixtures}, year = {2010}, month = {janvier}, booktitle = {Proc. of SPIE (IS&T/SPIE Electronic Imaging 2010)}, volume = {7533}, pages = {753308}, address = {San Jose, USA}, url = {http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=776565}, pdf = {http://hal.archives-ouvertes.fr/inria-00442348/en/}, keyword = {SAR image classification, Dictionnaire, amplitude probability density, EM Stochastique (SEM), Markov random field, copula} } Abstract : In this paper we develop a novel classification approach for high and very high resolution polarimetric synthetic aperture radar (SAR) amplitude images. This approach combines the Markov random field model to Bayesian image classification and a finite mixture technique for probability density function estimation. The finite mixture modeling is done via a recently proposed dictionary-based stochastic expectation maximization approach for SAR amplitude probability density function estimation. For modeling the joint distribution from marginals corresponding to single polarimetric channels we employ copulas. The accuracy of the developed semiautomatic supervised algorithm is validated in the application of wet soil classification on several high resolution SAR images acquired by TerraSAR-X and COSMO-SkyMed.

42 - A marked point process model with strong prior shape information for extraction of multiple, arbitrarily-shaped objects. M. S. Kulikova et I. H. Jermyn et X. Descombes et E. Zhizhina et J. Zerubia. Dans Proc. IEEE SITIS, Publ. IEEE Computer Society, Marrakech, Maroc, décembre 2009. Mots-clés : Extraction d'objets, Processus ponctuels marques, Shape prior, Contour actif, multiple birth-and-death dynamics. @INPROCEEDINGS{Kulikova09a, author = {Kulikova, M. S. and Jermyn, I. H. and Descombes, X. and Zhizhina, E. and Zerubia, J.}, title = {A marked point process model with strong prior shape information for extraction of multiple, arbitrarily-shaped objects}, year = {2009}, month = {décembre}, booktitle = {Proc. IEEE SITIS}, publisher = {IEEE Computer Society}, address = {Marrakech, Maroc}, pdf = {http://hal.inria.fr/docs/00/43/63/20/PDF/PID1054029.pdf}, keyword = {Extraction d'objets, Processus ponctuels marques, Shape prior, Contour actif, multiple birth-and-death dynamics} } Abstract : We define a method for incorporating strong prior shape information into a recently extended Markov point process model for the extraction of arbitrarily-shaped objects from images. To estimate the optimal configuration of objects, the process is sampled using a Markov chain based on a stochastic birth-and-death process defined in a space of multiple objects. The single objects considered are defined by both the image data and the prior information in a way that controls the computational complexity of the estimation problem. The method is tested via experiments on a very high resolution aerial image of a scene composed of tree crowns.

43 - Building Extraction and Change Detection in Multitemporal Remotely Sensed Images with Multiple Birth and Death Dynamics. C. Benedek et X. Descombes et J. Zerubia. Dans IEEE Workshop on Applications of Computer Vision (WACV), pages 100-105, Snowbird, Utah, USA, décembre 2009. Mots-clés : Processus ponctuels marques, Change detection, Aerial images, Building extraction, Imagerie satellitaire. @INPROCEEDINGS{benedekWacv09, author = {Benedek, C. and Descombes, X. and Zerubia, J.}, title = {Building Extraction and Change Detection in Multitemporal Remotely Sensed Images with Multiple Birth and Death Dynamics}, year = {2009}, month = {décembre}, booktitle = {IEEE Workshop on Applications of Computer Vision (WACV)}, pages = {100-105}, address = {Snowbird, Utah, USA}, pdf = {http://hal.archives-ouvertes.fr/docs/00/42/66/18/PDF/benedekWACV09.pdf}, keyword = {Processus ponctuels marques, Change detection, Aerial images, Building extraction, Imagerie satellitaire} } Abstract : In this paper we introduce a new probabilistic method which integrates building extraction with change detection in remotely sensed image pairs. A global optimization process attempts to find the optimal configuration of buildings, considering the observed data, prior knowledge, and interactions between the neighboring building parts. The accuracy is ensured by a Bayesian object model verification, meanwhile the computational cost is significantly decreased by a non-uniform stochastic object birth process, which proposes relevant objects with higher probability based on low-level image features.

44 - Reconstruction 3D du bâti par la technique des ombres chinoises. P. Lukashevish et A. Kraushonak et X. Descombes et J.D. Durou et B. Zalessky et E. Zhizhina. Dans GRETSI Dijon, Dijon, France, novembre 2009. Mots-clés : Reconstruction en 3D. @INPROCEEDINGS{luka09, author = {Lukashevish, P. and Kraushonak, A. and Descombes, X. and Durou, J.D. and Zalessky, B. and Zhizhina, E.}, title = {Reconstruction 3D du bâti par la technique des ombres chinoises}, year = {2009}, month = {novembre}, booktitle = {GRETSI Dijon}, address = {Dijon, France}, url = {http://hal.inria.fr/inria-00399208/fr/}, keyword = {Reconstruction en 3D} }

45 - Combining meshes and geometric primitives for accurate and semantic modeling. F. Lafarge et R. Keriven et M. Brédif. Dans Proc. British Machine Vision Conference (BMVC), London, U.K., novembre 2009. @INPROCEEDINGS{lafarge_bmvc09, author = {Lafarge, F. and Keriven, R. and Brédif, M.}, title = {Combining meshes and geometric primitives for accurate and semantic modeling}, year = {2009}, month = {novembre}, booktitle = {Proc. British Machine Vision Conference (BMVC)}, address = {London, U.K.}, url = {http://recherche.ign.fr/labos/matis/pdf/articles_conf/2009/bmvc_final_09.pdf}, keyword = {} }

46 - A markov random field model for extracting near-circular shapes. T. Blaskovics et Z. Kato et I. H. Jermyn. Dans Proc. IEEE International Conference on Image Processing (ICIP), Cairo, Egypt, novembre 2009. Mots-clés : Segmentation, Markov Random Fields, Shape prior. @INPROCEEDINGS{Blaskovics09, author = {Blaskovics, T. and Kato, Z. and Jermyn, I. H.}, title = {A markov random field model for extracting near-circular shapes}, year = {2009}, month = {novembre}, booktitle = {Proc. IEEE International Conference on Image Processing (ICIP)}, address = {Cairo, Egypt}, pdf = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5413472}, keyword = {Segmentation, Markov Random Fields, Shape prior} }

47 - Object extraction from high resolution SAR images using a birth and death dynamics. F. Arslan et X. Descombes et J. Zerubia. Dans Proc. IEEE International Conference on Image Processing (ICIP), Cairo, Egypt, novembre 2009. Mots-clés : High resolution SAR images, Extraction d'objets, Processus ponctuels marques, birth and death process. @INPROCEEDINGS{Fatih09, author = {Arslan, F. and Descombes, X. and Zerubia, J.}, title = {Object extraction from high resolution SAR images using a birth and death dynamics}, year = {2009}, month = {novembre}, booktitle = {Proc. IEEE International Conference on Image Processing (ICIP)}, address = {Cairo, Egypt}, url = {http://dx.doi.org/10.1109/ICIP.2009.5413907}, keyword = {High resolution SAR images, Extraction d'objets, Processus ponctuels marques, birth and death process} } Abstract : We present a new approach to extract predefined objects, such as trees and oil tanks for instance, from high resolution SAR images. We consider a stochastic approach based on an object process also called marked point process. The objects represent trees or oil tanks which are modeled by disks in the image. We first define a Gibbs density that takes into account both prior information and the data. The energy we define is composed of two terms, one is a prior, penalizing overlaps between objects, and the other is a data term, which measures the suitability of an object in the SAR image. The problem is then reduced to an energy minimization problem. We sample the process to extract the configuration of objects minimizing the energy by a fast birth-and-death dynamics, leading to the total number of objects (trees or oil tanks in our case). This approach is much faster than manual counts and does not need any preprocessing or supervision of a user.

48 - Multi-class SVM for forestry classification. N. Hajj Chehade et JG. Boureau et C. Vidal et J. Zerubia. Dans Proc. IEEE International Conference on Image Processing (ICIP), Cairo, Egypt, novembre 2009. Mots-clés : Support Vector Machines, texture segmentation, Haralick feature, remote sensing, Forest vegetation. @INPROCEEDINGS{Nabil09, author = {Hajj Chehade, N. and Boureau, JG. and Vidal, C. and Zerubia, J.}, title = {Multi-class SVM for forestry classification}, year = {2009}, month = {novembre}, booktitle = {Proc. IEEE International Conference on Image Processing (ICIP)}, address = {Cairo, Egypt}, url = {http://dx.doi.org/10.1109/ICIP.2009.5413395}, keyword = {Support Vector Machines, texture segmentation, Haralick feature, remote sensing, Forest vegetation} } Abstract : In this paper we propose a method for classifying the vegetation types in an aerial color infra-red (CIR) image. Different vegetation types do not only differ in color, but also in texture. We study the use of four Haralick features (energy, contrast, entropy, homogeneity) for texture analysis, and then perform the classification using the one-against-all (OAA) multi-class support vector machine (SVM), which is a popular supervised learning technique for classification. The choice of features (along with their corresponding parameters), the choice of the training set, and the choice of the SVM kernel highly affect the performance of the classification. The study was done on several CIR aerial images provided by the French National Forest Inventory (IFN). In this paper, we will show one example on a national forest near Sedan (in France), and compare our result with the IFN map.

49 - Estimation des paramètres de processus ponctuels marqués dans le cadre de l'extraction d’objets en imagerie de télédétection. F. Chatelain et X. Descombes et J. Zerubia. Dans Proc. Symposium on Signal and Image Processing (GRETSI), Dijon, France, novembre 2009. @INPROCEEDINGS{cha09a, author = {Chatelain, F. and Descombes, X. and Zerubia, J.}, title = {Estimation des paramètres de processus ponctuels marqués dans le cadre de l'extraction d’objets en imagerie de télédétection}, year = {2009}, month = {novembre}, booktitle = {Proc. Symposium on Signal and Image Processing (GRETSI)}, address = {Dijon, France}, url = {http://hal.inria.fr/inria-00399258/fr/}, keyword = {} }

50 - Lidar Waveform Modeling using a Marked Point Process. C. Mallet et F. Lafarge et F. Bretar et U. Soergel et C. Heipke. Dans Proc. IEEE International Conference on Image Processing (ICIP), Cairo, Egypt, novembre 2009. Mots-clés : 3D point cloud, Lidar, Marked point process, RJMCMC. @INPROCEEDINGS{mallet_icip09, author = {Mallet, C. and Lafarge, F. and Bretar, F. and Soergel, U. and Heipke, C.}, title = {Lidar Waveform Modeling using a Marked Point Process}, year = {2009}, month = {novembre}, booktitle = {Proc. IEEE International Conference on Image Processing (ICIP)}, address = {Cairo, Egypt}, url = {http://dx.doi.org/10.1109/ICIP.2009.5413380}, keyword = {3D point cloud, Lidar, Marked point process, RJMCMC} } Abstract : Lidar waveforms are 1D signal consisting of a train of echoes where each of them correspond to a scattering target of the Earth surface. Modeling these echoes with the appropriate parametric function is necessary to retrieve physical information about these objects and characterize their properties. This paper presents a marked point process based model to reconstruct a lidar signal in terms of a set of parametric functions. The model takes into account both a data term which measures the coherence between the models and the waveforms, and a regularizing term which introduces physical knowledge on the reconstructed signal. We search for the best configuration of functions by performing a Reversible Jump Markov Chain Monte Carlo sampler coupled with a simulated annealing. Results are finally presented on different kinds of signals in urban areas.

51 - A phase field higher-order active contour model of directed networks. A. El Ghoul et I. H. Jermyn et J. Zerubia. Dans 2nd IEEE Workshop on Non-Rigid Shape Analysis and Deformable Image Alignment, at ICCV, Kyoto, Japan, septembre 2009. Mots-clés : Geometric prior, Forme, Higher-order actif contours, Champ de Phase, Directed networks. Copyright : ©2009 IEEE. @INPROCEEDINGS{ElGhoul09b, author = {El Ghoul, A. and Jermyn, I. H. and Zerubia, J.}, title = {A phase field higher-order active contour model of directed networks}, year = {2009}, month = {septembre}, booktitle = {2nd IEEE Workshop on Non-Rigid Shape Analysis and Deformable Image Alignment, at ICCV}, address = {Kyoto, Japan}, url = {https://hal.inria.fr/inria-00409910}, pdf = {http://hal.inria.fr/docs/00/40/99/10/PDF/nordia09aymenelghoul.pdf}, keyword = {Geometric prior, Forme, Higher-order actif contours, Champ de Phase, Directed networks} } Abstract : The segmentation of directed networks is an important problem in many domains, e.g. medical imaging (vascular networks) and remote sensing (river networks). Directed networks carry a unidirectional flow in each branch, which leads to characteristic geometric properties. In this paper, we present a nonlocal phase field model of directed networks. In addition to a scalar field representing a region by its smoothed characteristic function and interacting nonlocally so as to favour network configurations, the model contains a vector field representing the ‘flow’ through the network branches. The vector field is strongly encouraged to be zero outside, and of unit magnitude inside the region; and to have zero divergence. This prolongs network branches; controls width variation along a branch; and produces asymmetric junctions for which total incoming branch width approximately equals total outgoing branch width. In conjunction with a new interaction function, it also allows a broad range of stable branch widths. We analyse the energy to constrain the parameters, and show geometric experiments confirming the above behaviour. We also show a segmentation result on a synthetic river image.

52 - Algorithme rapide pour la restauration d'image régularisée sur les coefficients d'ondelettes. M. Carlavan et P. Weiss et L. Blanc-Féraud et J. Zerubia. Dans Proc. Symposium on Signal and Image Processing (GRETSI), Dijon, France, septembre 2009. Mots-clés : Deconvolution, nesterov scheme, Ondelettes, l1 norm. @INPROCEEDINGS{GRETSICarlavan09, author = {Carlavan, M. and Weiss, P. and Blanc-Féraud, L. and Zerubia, J.}, title = {Algorithme rapide pour la restauration d'image régularisée sur les coefficients d'ondelettes}, year = {2009}, month = {septembre}, booktitle = {Proc. Symposium on Signal and Image Processing (GRETSI)}, address = {Dijon, France}, url = {http://www.math.univ-toulouse.fr/~weiss/Publis/Conferences/CarlavanGretsi09.pdf}, pdf = {http://www.math.univ-toulouse.fr/~weiss/Publis/Conferences/CarlavanGretsi09.pdf}, keyword = {Deconvolution, nesterov scheme, Ondelettes, l1 norm} } Résumé : De nombreuses méthodes de restauration d'images consistent à minimiser une énergie convexe. Nous nous focalisons sur l'utilisation de ces méthodes et considérons la minimisation de deux critères contenant une norme l1 des coefficients en ondelettes. La plupart des travaux publiés récemment proposent un critère à minimiser dans le domaine des coefficients en ondelettes, utilisant ainsi un a priori de parcimonie. Nous proposons un algorithme rapide et des résultats de déconvolution par minimisation d'un critère dans le domaine image, avec un a priori de régularité exprimé dans le domaine image utilisant une décomposition redondante sur une trame. L'algorithme et le modèle proposés semblent originaux pour ce problème en traitement d'images et sont performants en terme de temps de calculs et de qualité de restauration. Nous montrons des comparaisons entre les deux types d' a priori. Abstract : Many image restoration techniques are based on convex energy minimization. We focus on the use of these techniques and consider the minimization of two criteria holding a l1-norm of wavelet coefficients. Most of the recent research works are based on the minimization of a criterion in the wavelet coefficients domain, namely as a sparse prior. We propose a fast algorithm and deconvolution results obtained by minimizing a criterion in the image domain using a redundant decomposition on a frame. The algorithm and model proposed are unusual for this problem and very efficient in term of computing time and quality of restoration results. We show comparisons between the two different priors.

53 - Estimation d'hyperparamètres pour la résolution de problèmes inverses à l'aide d'ondelettes. C. Chaux et L. Blanc-Féraud. Dans Proc. Symposium on Signal and Image Processing (GRETSI), Dijon, France, septembre 2009. @INPROCEEDINGS{ChauxGRETSI09, author = {Chaux, C. and Blanc-Féraud, L.}, title = {Estimation d'hyperparamètres pour la résolution de problèmes inverses à l'aide d'ondelettes}, year = {2009}, month = {septembre}, booktitle = {Proc. Symposium on Signal and Image Processing (GRETSI)}, address = {Dijon, France}, url = {http://hdl.handle.net/2042/28911}, keyword = {} } Résumé : Nous nous intéressons à l'estimation des paramètres de régularisation pour la restauration d'image floue et bruitée. Dans l'approche variationnelle, la restauration consiste à minimiser un critère convexe composé d'un terme de rappel aux données (quadratique) et d'un terme de régularisation (norme I1) opérant dans le domaine ondelettes. Nous proposons une méthode d'estimation des paramètres de régularisation (hyperparamètres, un par sous-bande) par maximum de vraisemblance, à partir de la seule image observée. La difficulté de l'estimation en données incomplètes est de pouvoir échantillonner des lois sur des champs de variables aléatoires dont les interactions entre voisins sont étendues, du fait de l'opérateur linéaire de flou. Nous proposons une méthode qui permet de calculer ces échantillons par MCMC (échantillonnage de Gibbs et Metropolis-Hastings). Pour l'estimation, nous utilisons une méthode de gradient. Les résultats de simulation obtenus montrent la faisabilité de la méthode et ses bonnes performances en terme d'estimation.

54 - Inflection point model under phase field higher-order active contours for network extraction from VHR satellite images. A. El Ghoul et I. H. Jermyn et J. Zerubia. Dans Proc. European Signal Processing Conference (EUSIPCO), Glasgow, Scotland, août 2009. Mots-clés : Geometric prior, Forme, Contour actif d'ordre supérieur, Champ de Phase, remote sensing. Copyright : EURASIP @INPROCEEDINGS{ElGhoul09a, author = {El Ghoul, A. and Jermyn, I. H. and Zerubia, J.}, title = {Inflection point model under phase field higher-order active contours for network extraction from VHR satellite images}, year = {2009}, month = {août}, booktitle = {Proc. European Signal Processing Conference (EUSIPCO)}, address = {Glasgow, Scotland}, url = {http://hal.inria.fr/inria-00390446/fr/}, pdf = {http://hal.inria.fr/docs/00/39/04/46/PDF/eusipco09aymenelghoul.pdf}, keyword = {Geometric prior, Forme, Contour actif d'ordre supérieur, Champ de Phase, remote sensing} } Abstract : The segmentation of networks is important in several imaging domains, and models incorporating prior shape knowledge are often essential for the automatic performance of this task. We incorporate such knowledge via phase fields and higher-order active contours (HOACs). In this paper: we introduce an improved prior model, the phase field HOAC ‘inflection point’ model of a network; we present an improved data term for the segmentation of road networks; we confirm the robustness of the resulting model to choice of gradient descent initialization; and we illustrate these points via road network extraction results on VHR satellite images.

55 - Parameter estimation for marked point processes. Application to object extraction from remote sensing images. (poster). F. Chatelain et X. Descombes et J. Zerubia. Dans Proc. Energy Minimization Methods in Computer Vision and Pattern Recognition (EMMCVPR), Bonn, Germany, août 2009. @INPROCEEDINGS{ChatelainEMMCVPR09, author = {Chatelain, F. and Descombes, X. and Zerubia, J.}, title = {Parameter estimation for marked point processes. Application to object extraction from remote sensing images. (poster)}, year = {2009}, month = {août}, booktitle = {Proc. Energy Minimization Methods in Computer Vision and Pattern Recognition (EMMCVPR)}, address = {Bonn, Germany}, url = {http://link.springer.com/chapter/10.1007%2F978-3-642-03641-5_17}, keyword = {} }

56 - A proximal method for inverse problems in image processing. P. Weiss et L. Blanc-Féraud. Dans Proc. European Signal Processing Conference (EUSIPCO), Glasgow, Scotland, août 2009. Mots-clés : Extragradient method, proximal method, Decomposition d'images, Meyer's model, convergence rate. @INPROCEEDINGS{PWEISS_Eusipco, author = {Weiss, P. and Blanc-Féraud, L.}, title = {A proximal method for inverse problems in image processing}, year = {2009}, month = {août}, booktitle = {Proc. European Signal Processing Conference (EUSIPCO)}, address = {Glasgow, Scotland}, url = {http://www.math.univ-toulouse.fr/~weiss/Publis/Conferences/Eusipco09.pdf}, pdf = {http://www.math.univ-toulouse.fr/~weiss/Publis/Conferences/Eusipco09.pdf}, keyword = {Extragradient method, proximal method, Decomposition d'images, Meyer's model, convergence rate} } Abstract : In this paper, we present a new algorithm to solve some inverse problems coming from the field of image processing. The models we study consist in minimizing a regularizing, convex criterion under a convex and compact set. The main idea of our scheme consists in solving the underlying variational inequality with a proximal method rather than the initial convex problem. Using recent results of A. Nemirovski [13], we show that the scheme converges at least as O(1/k) (where k is the iteration counter). This is in some sense an optimal rate of convergence. Finally, we compare this approach to some others on a problem of image cartoon+texture decomposition.

57 - Complex wavelet regularization for solving inverse problems in remote sensing. M. Carlavan et P. Weiss et L. Blanc-Féraud et J. Zerubia. Dans Proc. IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Cape Town, South Africa, juillet 2009. Mots-clés : Deconvolution, Dual smoothing, nesterov scheme, remote sensing, wavelet. @INPROCEEDINGS{IGARSSCarlavan09, author = {Carlavan, M. and Weiss, P. and Blanc-Féraud, L. and Zerubia, J.}, title = {Complex wavelet regularization for solving inverse problems in remote sensing}, year = {2009}, month = {juillet}, booktitle = {Proc. IEEE International Geoscience and Remote Sensing Symposium (IGARSS)}, address = {Cape Town, South Africa}, url = {http://www.math.univ-toulouse.fr/~weiss/Publis/Conferences/IGARSS09.pdf}, pdf = {http://www.math.univ-toulouse.fr/~weiss/Publis/Conferences/IGARSS09.pdf}, keyword = {Deconvolution, Dual smoothing, nesterov scheme, remote sensing, wavelet} } Abstract : Many problems in remote sensing can be modeled as the minimization of the sum of a data term and a prior term. We propose to use a new complex wavelet based prior and an efficient scheme to solve these problems. We show some results on a problem of image reconstruction with noise, irregular sampling and blur. We also show a comparison between two widely used priors in image processing: sparsity and regularity priors.

58 - Conditional mixed-state model for structural change analysis from very high resolution optical images. B. Belmudez et V. Prinet et J.F. Yao et P. Bouthemy et X. Descombes. Dans Proc. IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Cape Town, South Africa, juillet 2009. Mots-clés : Change detection, mixed Markov models. @INPROCEEDINGS{bel09, author = {Belmudez, B. and Prinet, V. and Yao, J.F. and Bouthemy, P. and Descombes, X.}, title = {Conditional mixed-state model for structural change analysis from very high resolution optical images}, year = {2009}, month = {juillet}, booktitle = {IGARSS}, address = {Cape Town, South Africa}, url = {http://hal.archives-ouvertes.fr/inria-00398062/}, keyword = {Change detection, mixed Markov models} } Abstract : The present work concerns the analysis of dynamic scenes from earth observation images. We are interested in building a map which, on one hand locates places of change, on the other hand, reconstructs a unique visual information of the non-change areas. We show in this paper that such a problem can naturally be takled with conditional mixed-state random field modeling (mixed-state CRF), where the ”mixed state” refers to the symbolic or continous nature of the unknown variable. The maximum a posteriori (MAP) estimation of the CRF is, through the Hammersley-Clifford theorem, turned into an energy minimisation problem. We tested the model on several Quickbird images and illustrate the quality of the results.

59 - Point-spread function retrieval for fluorescence microscopy. P. Pankajakshan et L. Blanc-Féraud et Z. Kam et J. Zerubia. Dans Proc. IEEE International Symposium on Biomedical Imaging (ISBI), Publ. IEEE, Org. IEEE, Boston, USA, juin 2009. Mots-clés : fluorescence microscopy, point spread function, Algorithme EM, Deconvolution. Copyright : Copyright 2009 IEEE. Published in the 2009 International Symposium on Biomedical Imaging: From Nano to Macro (ISBI 2009), scheduled for June 28 - July 1, 2009 in Boston, Massachusetts, U.S.A. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works, must be obtained from the IEEE. Contact: Manager, Copyrights and Permissions / IEEE Service Center / 445 Hoes Lane / P.O. Box 1331 / Piscataway, NJ 08855-1331, USA. Telephone: + Intl. 908-562-3966. @INPROCEEDINGS{ppankajakshan09a, author = {Pankajakshan, P. and Blanc-Féraud, L. and Kam, Z. and Zerubia, J.}, title = {Point-spread function retrieval for fluorescence microscopy}, year = {2009}, month = {juin}, booktitle = {Proc. IEEE International Symposium on Biomedical Imaging (ISBI)}, publisher = {IEEE}, organization = {IEEE}, address = {Boston, USA}, pdf = {http://hal.inria.fr/docs/00/39/55/34/PDF/pankajakshan.pdf}, keyword = {fluorescence microscopy, point spread function, Algorithme EM, Deconvolution} } Abstract : In this paper we propose a method for retrieving the Point-Spread Function (PSF) of an imaging system given the observed images of fluorescent microspheres. Theoretically calculated PSFs often lack the experimental or microscope specific signatures while empirically obtained data are either over sized or (and) too noisy. The effect of noise and the influence of the microsphere size can be mitigated from the experimental data by using a Maximum Likelihood Expectation Maximization (MLEM) algorithm. The true experimental parameters can then be estimated by fitting the result to a model based on the scalar diffraction theory. The algorithm was tested on some simulated data and the results obtained validate the usefulness of the approach for retrieving the PSF from measured data.

60 - A new variational method to detect points in biological images. D. Graziani et L. Blanc-Féraud et G. Aubert. Dans ISBI'09, Org. IEEE International Symposium on Biomedical Imaging, Boston, USA, juin 2009. Mots-clés : Images biologiques, points detection, Gamma-convergence. @INPROCEEDINGS{GRAZIANI_ISBI2009, author = {Graziani, D. and Blanc-Féraud, L. and Aubert, G.}, title = {A new variational method to detect points in biological images}, year = {2009}, month = {juin}, booktitle = {ISBI'09}, organization = {IEEE International Symposium on Biomedical Imaging}, address = {Boston, USA}, url = {http://dx.doi.org/10.1109/ISBI.2009.5193301}, keyword = {Images biologiques, points detection, Gamma-convergence} } Abstract : We propose a new variational method to isolate points in biological images. As points are fine structures they are difficult to detect by derivative operators computed in the noisy image. In this paper we propose to compute a vector field from the observed intensity so that its divergence explodes at points. As the image could contains spots but also noise and curves where the divergence also blows up, we propose to capture spots by introducing suitable energy whose minimizers are given by the points we want to detect. In order to provide numerical experiments we approximate this energy by means of a sequence of more treatable functionals by a Gamma-convergence approach. Results are shown on synthetic and biological images.

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