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In this paper, we consider the problem of feature reconstruction from incomplete x-ray CT data. Such problems occurs, e.g., as a result of dose reduction in the context medical imaging. Since image reconstruction from incomplete data is a…

Image and Video Processing · Electrical Eng. & Systems 2022-02-23 Simon Göppel , Jürgen Frikel , Markus Haltmeier

We propose a new algorithmic approach to the non-smooth and non-convex Potts problem (also called piecewise-constant Mumford-Shah problem) for inverse imaging problems. We derive a suitable splitting into specific subproblems that can all…

Optimization and Control · Mathematics 2015-03-03 Martin Storath , Andreas Weinmann , Jürgen Frikel , Michael Unser

The approximate discrete Radon transform (ADRT) is a hierarchical multiscale approximation of the Radon transform. In this paper, we factor the ADRT into a product of linear transforms that resemble convolutions and derive an explicit…

Numerical Analysis · Mathematics 2026-01-08 Weilin Li , Karl Otness , Kui Ren , Donsub Rim

The inverse source problem for the radiative transfer equation is considered, with partial data. Here it is shown that under certain smoothness conditions on the scattering and absorption coefficients, one can recover sources supported in a…

Analysis of PDEs · Mathematics 2015-05-28 Mark Hubenthal

In this article we present a review of the Radon transform and the instability of the tomographic reconstruction process. We show some new mathematical results in tomography obtained by a variational formulation of the reconstruction…

Mathematical Physics · Physics 2015-06-17 Paolo Facchi , Marilena Ligabò , Sergio Solimini

Tomography can be used to reveal internal properties of a 3D object using any penetrating wave. Advanced tomographic imaging techniques, however, are vulnerable to both systematic and random errors associated with the experimental…

Numerical Analysis · Mathematics 2019-02-08 Anthony P. Austin , Zichao Wendy Di , Sven Leyffer , Stefan M. Wild

We are concerned with the inverse scattering problem of extracting the geometric structures of an unknown/inaccessible inhomogeneous medium by using the corresponding acoustic far-field measurement. Using the intrinsic geometric properties…

Analysis of PDEs · Mathematics 2017-06-15 Jingzhi Li , Xiaofei Li , Hongyu Liu

We consider the two dimensional quantitative imaging problem of recovering a radiative source inside an absorbing and scattering medium from knowledge of the outgoing radiation measured at the boundary. The medium has an anisotropic…

Numerical Analysis · Mathematics 2021-01-21 Hiroshi Fujiwara , Kamran Sadiq , Alexandru Tamasan

Tomographic image reconstruction can be mapped to a problem of finding solutions to a large system of linear equations which maximize a function that includes \textit{a priori} knowledge regarding features of typical images such as…

Image and Video Processing · Electrical Eng. & Systems 2019-10-02 Anna Paola Muntoni , Rafael Díaz Hernández Rojas , Alfredo Braunstein , Andrea Pagnani , Isaac Pérez Castillo

This paper proves a novel analytical inversion formula for the so-called modulo Radon transform (MRT), which models a recently proposed approach to one-shot high dynamic range tomography. It is based on the solution of a Poisson problem…

Numerical Analysis · Mathematics 2024-12-10 Matthias Beckmann , Carla Dittert

We obtain new inversion formulas for the Funk type transforms of two kinds associated to spherical sections by hyperplanes passing through a common point $A$ which lies inside the n-dimensional unit sphere or on the sphere itself.…

Functional Analysis · Mathematics 2018-10-23 B. Rubin

We study integral transforms mapping a function on the Euclidean space to the family of its integration on some hypersurfaces, that is, a function of hypersurfaces. The hypersurfaces are given by the graphs of functions with fixed axes of…

Classical Analysis and ODEs · Mathematics 2020-06-08 Hiroyuki Chihara

A variational model for learning convolutional image atoms from corrupted and/or incomplete data is introduced and analyzed both in function space and numerically. Building on lifting and relaxation strategies, the proposed approach is…

Optimization and Control · Mathematics 2018-12-10 Antonin Chambolle , Martin Holler Thomas Pock

A new numerical method to solve an inverse source problem for the radiative transfer equation involving the absorption and scattering terms, with incomplete data, is proposed. No restrictive assumption on those absorption and scattering…

Numerical Analysis · Mathematics 2019-04-02 Alexey V. Smirnov , Michael V. Klibanov , Loc H. Nguyen

Radon Transformation is generally used to construct optical image (like CT image) from the projection data in biomedical imaging. In this paper, the concept of Radon Transformation is implemented to reconstruct Electrical Impedance…

Computer Vision and Pattern Recognition · Computer Science 2012-11-07 Md. Ali Hossain , Ahsan-Ul-Ambia , Md. Aktaruzzaman , Md. Ahaduzzaman Khan

Speckle Imaging based on triple correlation is a very efficient image reconstruction technique which is used to retrieve Fourier phase information of the object in presence of atmospheric turbulence. We have developed both Direct Bispectrum…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha

We study the spherical slice transform which assigns to a function on the $n$-dimensional unit sphere the integrals of that function over cross-sections of the sphere by $k$-dimensional affine planes passing through the north pole. These…

Functional Analysis · Mathematics 2021-08-03 Boris Rubin

We consider an inverse source problem in the stationary radiative transport through an absorbing and scattering medium in two dimensions. Using the angularly resolved radiation measured on an arc of the boundary, we propose a numerical…

Numerical Analysis · Mathematics 2023-06-08 Hiroshi Fujiwara , Kamran Sadiq , Alexandru Tamasan

The paper contains a simple proof of the Finch-Patch-Rakesh inversion formula for the spherical mean Radon transform in odd dimensions. This transform arises in thermoacoustic tomography. Applications are given to the Cauchy problem for the…

Functional Analysis · Mathematics 2007-11-14 Boris Rubin

We present a novel method for reconstructing the shape of an object from measured gradient data. A certain class of optical sensors does not measure the shape of an object, but its local slope. These sensors display several advantages,…

Optics · Physics 2009-11-13 Svenja Ettl , Jürgen Kaminski , Markus C. Knauer , Gerd Häusler