Carola Bibiane Schoenlieb, DAMTP University of Cambridge Learning variational regularization models for image denoising by PDE constrained optimization http://www.damtp.cam.ac.uk/user/cbs31/Home.html Mercoledì 17 Giugno 2015, ore 11:00 precise Dipartimento di Matematica del Politecnico - Aula Consiglio 7° piano |
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Abstract
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We review some recent learning approaches in variational image regularisation — in particular for variational image denoising — based on PDE constrained (also called bilevel) optimisation. Optimal solutions are typically parameters determining the type of regularisation and data discrepancy. A general type of regulariser is considered, which encompasses total variation (TV), total generalized variation (TGV) and infimal-convolution total variation (ICTV), as well as general data discrepancies encoding different noise distributions. We analyse those models for existence and structure of minimisers, as well as optimality conditions for their characterisation. Based on this information, Newton type methods are employed to solve the models numerically. The computational verification of the developed techniques will be discussed, covering instances with different type of regularisers, several noise models, spatially dependent weights and large image databases.
This is joint work with Luca Calatroni, Chung Cao, Juan Carlos De los Reyes, and Tuomo Valkonen. |
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Giovanni Gallavotti, Universita' di Roma Gruppo di rinormalizzaione, effetto Kondo e modelli gerarchici Lunedì 15 Giugno 2015, ore 17:00 precise Sala di Rappresentanza, Dipartimento di Matematica, Via Saldini |
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Andrei OKOUNKOV, Columbia University T.B.A. Lunedì 08 Giugno 2015, ore 16:30 precise Dipartimento di Matematica, Via Saldini, Aula Chisini | |
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Rita PARDINI, Università di Pisa Superfici di Godeaux stabili e curve bi-triellittiche di genere 2 Venerdì 22 Maggio 2015, ore 15:00 Sala Rappresentanza Dipartimento di Matematica Via Saldini 50 |
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Alexandru ALEMAN, University of Lund Fock-space models for evolution equations coming from quadratic differential operators Lunedì 18 Maggio 2015, ore 17:00 precise Sala Rappresentanza, Dipartimento di Matematica, Universita' di Milano, Via Saldini, 50 |
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Vieri Benci, Università di Pisa A new notion of generalized solution in PDE's Mercoledì 13 Maggio 2015, ore 17:00 precise Dipartimento di Matematica del Politecnico - Aula Consiglio 7° piano | |
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