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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. The proposed regularizer comes…

Image and Video Processing · Electrical Eng. & Systems 2019-08-05 Luca Calatroni , Alessandro Lanza , Monica Pragliola , Fiorella Sgallari

We propose a new space-variant regularization term for variational image restoration based on the assumption that the gradient magnitudes of the target image distribute locally according to a half-Generalized Gaussian distribution. This…

Image and Video Processing · Electrical Eng. & Systems 2019-06-27 Alessandro Lanza , Serena Morigi , Monica Pragliola , Fiorella Sgallari

We propose an efficient estimation technique for the automatic selection of locally-adaptive Total Variation regularisation parameters based on an hybrid strategy which combines a local maximum-likelihood approach estimating space-variant…

Optimization and Control · Mathematics 2020-05-20 Luca Calatroni , Alessandro Lanza , Monica Pragliola , Fiorella Sgallari

In this paper we propose a new approach for tomographic reconstruction with spatially varying regularization parameter. Our work is based on the SA-TV image restoration model proposed in [3] where an automated parameter selection rule for…

Numerical Analysis · Mathematics 2018-11-27 Yiqiu Dong , Carola-Bibiane Schönlieb

We propose an adaptive regularization scheme in a variational framework where a convex composite energy functional is optimized. We consider a number of imaging problems including denoising, segmentation and motion estimation, which are…

Computer Vision and Pattern Recognition · Computer Science 2017-03-01 Byung-Woo Hong , Ja-Keoung Koo , Hendrik Dirks , Martin Burger

We propose a new fast algorithm for solving one of the standard formulations of image restoration and reconstruction which consists of an unconstrained optimization problem where the objective includes an $\ell_2$ data-fidelity term and a…

Optimization and Control · Mathematics 2015-05-14 Manya V. Afonso , José M. Bioucas-Dias , Mário A. T. Figueiredo

Algorithms for automatically selecting a scalar or locally varying regularization parameter for total variation models with an $L^{\tau}$-data fidelity term, $\tau\in \{1,2\}$, are presented. The automated selection of the regularization…

Numerical Analysis · Mathematics 2017-01-02 Andreas Langer

Image segmentation is an inherently ill-posed problem and thus requires regularization in order to limit the search space to reasonable solutions. A majority of segmentation methods integrates these regularization terms in one way or the…

Numerical Analysis · Mathematics 2018-10-31 Uri Nahum , Philippe C. Cattin

The aim of this paper is to establish a nonlinear variational approach to the reconstruction of moving density images from indirect dynamic measurements. Our approach is to model the dynamics as a hyperelastic deformation of an initial…

Numerical Analysis · Mathematics 2015-12-01 Martin Burger , Jan Modersitzki , Sebastian Suhr

We propose two new variational models aimed to outperform the popular total variation (TV) model for image restoration with L$_2$ and L$_1$ fidelity terms. In particular, we introduce a space-variant generalization of the TV regularizer,…

Image and Video Processing · Electrical Eng. & Systems 2019-06-28 Alessandro Lanza , Serena Morigi , Monica Pragliola , Fiorella Sgallari

The curvature regularities are well-known for providing strong priors in the continuity of edges, which have been applied to a wide range of applications in image processing and computer vision. However, these models are usually non-convex,…

Numerical Analysis · Mathematics 2019-12-03 Qiuxiang Zhong , Ke Yin , Yuping Duan

Regularization approaches have demonstrated their effectiveness for solving ill-posed problems. However, in the context of variational restoration methods, a challenging question remains, which is how to find a good regularizer. While total…

Optimization and Control · Mathematics 2011-10-25 Nelly Pustelnik , Caroline Chaux , Jean-Christophe Pesquet

In this paper, we propose a new variational model for image reconstruction by minimizing the $L^1$ norm of the \emph{Weingarten map} of image surface $(x,y,f(x,y))$ for a given image $f:{\mathrm{\Omega}}\rightarrow \mathbb R$. We…

Numerical Analysis · Mathematics 2022-04-07 Qiuxiang Zhong , Ryan Wen Liu , Yuping Duan

In the last decades, unsupervised deep learning based methods have caught researchers attention, since in many real applications, such as medical imaging, collecting a great amount of training examples is not always feasible. Moreover, the…

Image and Video Processing · Electrical Eng. & Systems 2022-05-24 Pasquale Cascarano , Andrea Sebastiani , Maria Colomba Comes , Giorgia Franchini , Federica Porta

Image segmentation techniques are predominately based on parameter-laden optimization. The objective function typically involves weights for balancing competing image fidelity and segmentation regularization cost terms. Setting these…

Computer Vision and Pattern Recognition · Computer Science 2009-06-24 Josna Rao , Ghassan Hamarneh , Rafeef Abugharbieh

We present an adaptive regularization scheme for optimizing composite energy functionals arising in image analysis problems. The scheme automatically trades off data fidelity and regularization depending on the current data fit during the…

Computer Vision and Pattern Recognition · Computer Science 2017-05-10 Byung-Woo Hong , Ja-Keoung Koo , Martin Burger , Stefano Soatto

Owing to the edge preserving ability and low computational cost of the total variation (TV), variational models with the TV regularization have been widely investigated in the field of multiplicative noise removal. The key points of the…

Computer Vision and Pattern Recognition · Computer Science 2015-03-18 Dai-Qiang Chen , Li-Zhi Cheng

Much research has been devoted to the problem of restoring Poissonian images, namely for medical and astronomical applications. However, the restoration of these images using state-of-the-art regularizers (such as those based on multiscale…

Optimization and Control · Mathematics 2012-10-10 Mário A. T. Figueiredo , José M. Bioucas-Dias

In multiband fusion, an image with a high spatial and low spectral resolution is combined with an image with a low spatial but high spectral resolution to produce a single multiband image having high spatial and spectral resolutions. This…

Image and Video Processing · Electrical Eng. & Systems 2022-10-11 Unni V. S. , Pravin Nair , Kunal N. Chaudhury

We modify the total-variation-regularized image segmentation model proposed by Chan, Esedoglu and Nikolova [SIAM Journal on Applied Mathematics 66, 2006] by introducing local regularization that takes into account spatial image information.…

Numerical Analysis · Mathematics 2020-08-06 Laura Antonelli , Valentina De Simone , Daniela di Serafino
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