Méthodes proximales pour la résolution de problèmes inverses : application à la tomographie par émission de positrons

Abstract : The objective of this work is to propose reliable, efficient and fast methods for minimizing convex criteria, that are found in inverse problems for imagery. We focus on restoration/reconstruction problems when data is degraded with both a linear operator and noise, where the latter is not assumed to be necessarily additive.The methods reliability is ensured through the use of proximal algorithms, the convergence of which is guaranteed when a convex criterion is considered. Efficiency is sought through the choice of criteria adapted to the noise characteristics, the linear operators and the image specificities. Of particular interest are regularization terms based on total variation and/or sparsity of signal frame coefficients. As a consequence of the use of frames, two approaches are investigated, depending on whether the analysis or the synthesis formulation is chosen. Fast processing requirements lead us to consider proximal algorithms with a parallel structure. Theoretical results are illustrated on several large size inverse problems arising in image restoration, stereoscopy, multi-spectral imagery and decomposition into texture and geometry components. We focus on a particular application, namely Positron Emission Tomography (PET), which is particularly difficult because of the presence of a projection operator combined with Poisson noise, leading to highly corrupted data. To optimize the quality of the reconstruction, we make use of the spatio-temporal characteristics of brain tissue activity
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Contributor : Nelly Pustelnik <>
Submitted on : Friday, December 14, 2012 - 12:45:05 AM
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  • HAL Id : tel-00559126, version 5

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Nelly Pustelnik. Méthodes proximales pour la résolution de problèmes inverses : application à la tomographie par émission de positrons. Autre [cs.OH]. Université Paris-Est, 2010. Français. ⟨NNT : 2010PEST1037⟩. ⟨tel-00559126v5⟩

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