no code implementations • 10 Mar 2024 • Carlo Santambrogio, Monica Pragliola, Alessandro Lanza, Marco Donatelli, Luca Calatroni
We consider an unsupervised bilevel optimization strategy for learning regularization parameters in the context of imaging inverse problems in the presence of additive white Gaussian noise.
1 code implementation • 25 Jun 2023 • Fabio Merizzi, Perrine Saillard, Oceane Acquier, Elena Morotti, Elena Loli Piccolomini, Luca Calatroni, Rosa Maria Dessì
The unprecedented success of image reconstruction approaches based on deep neural networks has revolutionised both the processing and the analysis paradigms in several applied disciplines.
no code implementations • 20 Mar 2023 • Vasiliki Stergiopoulou, Subhadip Mukherjee, Luca Calatroni, Laure Blanc-Féraud
The spatial resolution of images of living samples obtained by fluorescence microscopes is physically limited due to the diffraction of visible light, which makes the study of entities of size less than the diffraction barrier (around 200 nm in the x-y plane) very challenging.
no code implementations • 24 Jan 2023 • Ilias Rentzeperis, Luca Calatroni, Laurent Perrinet, Dario Prandi
Compared to other methods, soft thresholding achieves this level of sparsity at the expense of much degraded reconstruction performance, that more likely than not is not acceptable in biological vision.
no code implementations • 11 Jan 2021 • Simone Rebegoldi, Luca Calatroni
The proposed algorithm is combined with an adaptive (non-monotone) backtracking strategy, which allows for the adjustment of the algorithmic step-size along the iterations in order to improve the convergence speed.
Deblurring Image Denoising Optimization and Control
1 code implementation • 28 Dec 2020 • Emre Baspinar, Luca Calatroni, Valentina Franceschi, Dario Prandi
We consider Wilson-Cowan-type models for the mathematical description of orientation-dependent Poggendorff-like illusions.
no code implementations • 22 Oct 2020 • Gabriele Scrivanti, Luca Calatroni, Serena Morigi, Lindsay Nicholson, Alin Achim
We propose a non-convex variational model for the super-resolution of Optical Coherence Tomography (OCT) images of the murine eye, by enforcing sparsity with respect to suitable dictionaries learnt from high-resolution OCT data.
1 code implementation • 19 Aug 2020 • Pasquale Cascarano, Luca Calatroni, Elena Loli Piccolomini
We consider a variational model for single-image super-resolution based on the assumption that the image gradient of the target image is sparse.
Image and Video Processing Numerical Analysis Numerical Analysis 65F22, 65K10 G.1.6; G.1.10; I.4.3; I.4.4; I.4.5; I.4.6
no code implementations • 15 Oct 2019 • Marcelo Bertalmío, Luca Calatroni, Valentina Franceschi, Benedetta Franceschiello, Dario Prandi
We consider the evolution model proposed in [9, 6] to describe illusory contrast perception phenomena induced by surrounding orientations.
no code implementations • 4 Oct 2019 • Simone Parisotto, Luca Calatroni, Aurélie Bugeau, Nicolas Papadakis, Carola-Bibiane Schönlieb
We propose a new variational model for non-linear image fusion.
no code implementations • 2 Aug 2019 • Luca Calatroni, Alessandro Lanza, Monica Pragliola, Fiorella Sgallari
In this paper we present a new regularization term for variational image restoration which can be regarded as a space-variant anisotropic extension of the classical isotropic Total Variation (TV) regularizer.
no code implementations • 18 Dec 2018 • Marcelo Bertalmío, Luca Calatroni, Valentina Franceschi, Benedetta Franceschiello, Dario Prandi
We consider a differential model describing neuro-physiological contrast perception phenomena induced by surrounding orientations.
1 code implementation • 17 Sep 2018 • Simone Parisotto, Luca Calatroni, Marco Caliari, Carola-Bibiane Schönlieb, Joachim Weickert
We present an anisotropic extension of the isotropic osmosis model that has been introduced by Weickert et al.~(Weickert, 2013) for visual computing applications, and we adapt it specifically to shadow removal applications.
Analysis of PDEs 68U10, 94A08, 49K20, 65M06,
1 code implementation • 19 Mar 2018 • Luca Calatroni, Marie d'Autume, Rob Hocking, Stella Panayotova, Simone Parisotto, Paola Ricciardi, Carola-Bibiane Schönlieb
The last fifty years have seen an impressive development of mathematical methods for the analysis and processing of digital images, mostly in the context of photography, biomedical imaging and various forms of engineering.
no code implementations • 27 Feb 2016 • Luca Calatroni, Yves van Gennip, Carola-Bibiane Schönlieb, Hannah Rowland, Arjuna Flenner
We consider the problem of scale detection in images where a region of interest is present together with a measurement tool (e. g. a ruler).
1 code implementation • 8 May 2015 • Luca Calatroni, Cao Chung, Juan Carlos De Los Reyes, Carola-Bibiane Schönlieb, Tuomo Valkonen
We review some recent learning approaches in variational imaging, based on bilevel optimisation, and emphasize the importance of their treatment in function space.