English
Related papers

Related papers: Fourier-based Inversion of Partial X-ray Transform…

200 papers

Waveform inversion is concerned with estimating a heterogeneous medium, modeled by variable coefficients of wave equations, using sources that emit probing signals and receivers that record the generated waves. It is an old and intensively…

Numerical Analysis · Mathematics 2024-10-29 Liliana Borcea , Josselin Garnier , Alexander V. Mamonov , Jörn Zimmerling

In this paper we couple Synchrotron Radiation (SR) theory with a branch of physical optics, namely laser beam optics. We show that the theory of laser beams is successful in characterizing radiation fields associated with any SR source.…

In the field of quantitative imaging, the image information at a pixel or voxel in an underlying domain entails crucial information about the imaged matter. This is particularly important in medical imaging applications, such as…

Optimization and Control · Mathematics 2024-04-12 Guozhi Dong , Moritz Flaschel , Michael Hintermüller , Kostas Papafitsoros , Clemens Sirotenko , Karsten Tabelow

This article studies the inverse problem of recovering a vector field supported in $\mathbb{D}_R$, the disk of radius $R$ centered at the origin, through a set of generalized broken ray/V-line transforms, namely longitudinal and transverse…

Classical Analysis and ODEs · Mathematics 2024-04-22 Rahul Bhardwaj , Rohit Kumar Mishra , Manmohan Vashisth

Traditional sampling schemes often assume that the sampling locations are known. Motivated by the recent bioimaging technique known as cryogenic electron microscopy (cryoEM), we consider the problem of reconstructing an unknown 3D structure…

Signal Processing · Electrical Eng. & Systems 2024-04-16 Renke Wang , Francien G. Bossema , Thierry Blu , Pier Luigi Dragotti

Many minimally invasive interventional procedures still rely on 2D fluoroscopic imaging. Generating a patient-specific 3D model from these X-ray projection data would allow to improve the procedural workflow, e.g. by providing assistance…

Image and Video Processing · Electrical Eng. & Systems 2021-02-08 Karthik Shetty , Annette Birkhold , Norbert Strobel , Bernhard Egger , Srikrishna Jaganathan , Markus Kowarschik , Andreas Maier

Diffusion models have become a popular approach for image generation and reconstruction due to their numerous advantages. However, most diffusion-based inverse problem-solving methods only deal with 2D images, and even recently published 3D…

Image and Video Processing · Electrical Eng. & Systems 2023-09-04 Suhyeon Lee , Hyungjin Chung , Minyoung Park , Jonghyuk Park , Wi-Sun Ryu , Jong Chul Ye

We consider the one-dimensional Schr\"odinger equation with a potential satisfying the standard assumptions of the inverse scattering theory and supported on the half-line $x\ge 0$. For this equation at fixed positive energy we give…

Mathematical Physics · Physics 2015-03-10 Roman Novikov

Interferometric closure invariants, constructed from triangular loops of mixed Fourier components, capture calibration-independent information on source morphology. While a complete set of closure invariants is directly obtainable from…

Instrumentation and Methods for Astrophysics · Physics 2024-11-20 Samuel Lai , Nithyanandan Thyagarajan , O. Ivy Wong , Foivos Diakogiannis , Lucas Hoefs

We derive a formula connecting the derivatives of parallel section functions of an origin-symmetric star body in R^n with the Fourier transform of powers of the radial function of the body. A parallel section function (or (n-1)-dimensional…

Metric Geometry · Mathematics 2016-09-07 Richard J. Gardner , Alexander Koldobsky , Thomas Schlumprecht

Fix $n \geq 2$ an integer, and $F$ be a totally real number field. We reduce the shifted convolution problem for $L$-function coefficients of $\operatorname{GL}_n({\bf{A}}_F)$-automorphic forms to the better-understood setting of…

Number Theory · Mathematics 2023-11-14 Jeanine Van Order

Generative models based on diffusion have become the state of the art in the last few years, notably for image generation. Here, we analyse them in the high-dimensional limit, where data are formed by a very large number of variables. We…

Disordered Systems and Neural Networks · Physics 2023-10-31 Giulio Biroli , Marc Mézard

Analytic expressions for the Fourier transforms of the Chebyshev and Legendre polynomials are derived, and the latter is used to find a new representation for the half-order Bessel functions. The numerical implementation of the so-called…

Numerical Analysis · Mathematics 2012-11-22 A. S. Fokas , S. A. Smitheman

Novel types of convolution operators for quaternion linear canonical transform (QLCT) are proposed. Type one and two are defined in the spatial and QLCT spectral domains, respectively. They are distinct in the quaternion space and are…

Classical Analysis and ODEs · Mathematics 2022-12-13 Xiaoxiao Hu , Dong Cheng , Kit Ian Kou

We derive new singular value decompositions and range characterizations for the X-ray transform on the Poincar\'e disk, intertwining relations with distinguished differential operators of wedge type, and a surjectivity result for the…

Analysis of PDEs · Mathematics 2025-08-20 Nikolas Eptaminitakis , François Monard , Yuzhou Zou

Inspired by the multiple-exposure fusion approach in computational photography, recently, several practitioners have explored the idea of high dynamic range (HDR) X-ray imaging and tomography. While establishing promising results, these…

Numerical Analysis · Mathematics 2024-04-10 Matthias Beckmann , Ayush Bhandari , Meira Iske

We prove conditions for the existence of a continuous linear right inverse for a surjective convolution operator in spaces of germs of analytic functions on convex subsets of the complex plane. Considered convex sets have a countable…

Functional Analysis · Mathematics 2018-10-22 S. N. Melikhov , L. V. Khanina

We study random variables of the form $f(X)$, when $f$ is a degree $d$ polynomial, and $X$ is a random vector on $\mathbb{R}^{n}$, motivated towards a deeper understanding of the covariance structure of $X^{\otimes d}$. For applications,…

Probability · Mathematics 2022-07-15 Itay Glazer , Dan Mikulincer

This PhD thesis studies the broken ray transform, a generalization of the geodesic X-ray transform where geodesics are replaced with broken rays that reflect on a part of the boundary. The fundamental question is whether this transform is…

Differential Geometry · Mathematics 2014-09-29 Joonas Ilmavirta

Computed Tomography (CT) is an essential non-destructive three dimensional imaging modality used in medicine, security screening, and inspection of manufactured components. Typical CT data acquisition entails the collection of a thousand or…

Medical Physics · Physics 2024-10-11 Kyle M. Champley , Michael B. Zellner , Joseph W. Tringe , Harry E. Martz
‹ Prev 1 8 9 10 Next ›