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X-ray imaging is indispensable in medical diagnostics, yet its use is tightly regulated due to potential health risks. To mitigate radiation exposure, recent research focuses on generating novel views from sparse inputs and reconstructing…

Computer Vision and Pattern Recognition · Computer Science 2025-03-12 Feiran Wang , Jiachen Tao , Junyi Wu , Haoxuan Wang , Bin Duan , Kai Wang , Zongxin Yang , Yan Yan

Under a convexity assumption on the boundary we solve a local inverse problem, namely we show that the geodesic X-ray transform can be inverted locally in a stable manner; one even has a reconstruction formula. We also show that under an…

Differential Geometry · Mathematics 2012-10-09 Gunther Uhlmann , András Vasy

A recent generalization of the Central Limit Theorem consistent with nonextensive statistical mechanics has been recently achieved through a generalized Fourier transform, noted $q$-Fourier transform. A representation formula for the…

Statistical Mechanics · Physics 2009-11-13 Sabir Umarov , Constantino Tsallis

The translation of an early (1957), Russian article on the development of x-ray computed tomography is provided. The article demonstrates a principle possibility of determining the local attenuation coefficient in every element of a…

History and Philosophy of Physics · Physics 2020-01-14 Alex Gustschin

A new approach is proposed for reconstruction of images from Radon projections. Based on Fourier expansions in orthogonal polynomials of two and three variables, instead of Fourier transforms, the approach provides a new algorithm for the…

Classical Analysis and ODEs · Mathematics 2007-05-23 Yuan Xu

In certain three-dimensional (3D) applications of photoacoustic computed tomography (PACT), including \textit{in vivo} breast imaging, hemispherical measurement apertures that enclose the object within their convex hull are employed for…

This paper presents a novel approach on solving the phase problem in nuclear magnetic resonance (NMR) diffusion pore imaging, a method, which allows imaging the shape of arbitrary closed pores filled with an NMR-detectable medium for…

Talbot-Lau X-ray phase-contrast imaging is a novel imaging modality, which provides not only an X-ray absorption image, but also additionally a differential phase image and a dark-field image. The dark-field image is related to small angle…

Medical Physics · Physics 2019-03-05 Shiyang Hu , Lina Felsner , Andreas Maier , Veronika Ludwig , Gisela Anton , Christian Riess

We introduce visual deprojection: the task of recovering an image or video that has been collapsed along a dimension. Projections arise in various contexts, such as long-exposure photography, where a dynamic scene is collapsed in time to…

Computer Vision and Pattern Recognition · Computer Science 2019-09-04 Guha Balakrishnan , Adrian V. Dalca , Amy Zhao , John V. Guttag , Fredo Durand , William T. Freeman

We propose a new approach to constructing globally strictly convex objective functional in a 1-D inverse medium scattering problem using multi-frequency backscattering data. The global convexity of the proposed objective functional is…

Numerical Analysis · Mathematics 2024-12-20 Thanh T. Nguyen , Michael V. Klibanov

This paper uses the convolution theorem of the Laplace transform to derive new inverse Laplace transforms for the product of two parabolic cylinder functions in which the arguments may have opposite sign. These transforms are subsequently…

Classical Analysis and ODEs · Mathematics 2019-08-02 Dirk Veestraeten

We have developed an algorithm for transferring radiation in three-dimensional space. The algorithm computes radiation source and sink terms using the Fast Fourier Transform (FFT) method, based on a formulation in which the integral of any…

Astrophysics · Physics 2009-11-07 Renyue Cen

Computed tomography is a method for synthesizing volumetric or cross-sectional images of an object from a collection of projections. Popular reconstruction methods for computed tomography are based on idealized models and assumptions that…

Numerical Analysis · Mathematics 2022-03-03 Frederik H. Pedersen , Jakob S. Jørgensen , Martin S. Andersen

Current deep learning-based solutions for image analysis tasks are commonly incapable of handling problems to which multiple different plausible solutions exist. In response, posterior-based methods such as conditional Diffusion Models and…

X-Ray imaging is quick, cheap and useful for front-line care assessment and intra-operative real-time imaging (e.g., C-Arm Fluoroscopy). However, it suffers from projective information loss and lacks vital volumetric information on which…

Image and Video Processing · Electrical Eng. & Systems 2020-06-24 Athanasios Vlontzos , Samuel Budd , Benjamin Hou , Daniel Rueckert , Bernhard Kainz

In this paper we study the performance of image reconstruction methods from incomplete samples of the 2D discrete Fourier transform. Inspired by requirements in parallel MRI, we focus on a special sampling pattern with a small number of…

Numerical Analysis · Mathematics 2025-10-22 Gerlind Plonka , Anahita Riahi

We construct examples of two convex bodies $K,L$ in $\mathbb{R}^n$, such that every projection of $K$ onto a $(n-1)$-dimensional subspace can be rotated to be contained in the corresponding projection of $L$, but $K$ itself cannot be…

Metric Geometry · Mathematics 2015-05-22 M. Angeles Alfonseca , Michelle Cordier

In this work, we describe examples for calculating the 1-D circular convolution of signals represented by 3-qubit superpositions. The case is considered, when the discrete Fourier transform of one of the signals is known and calculated in…

Quantum Physics · Physics 2022-05-13 Artyom M. Grigoryan , Sos S. Agaian

In this paper, we address the problem of recovering point sources from two dimensional low-pass measurements, which is known as super-resolution problem. This is the fundamental concern of many applications such as electronic imaging,…

Information Theory · Computer Science 2019-05-17 Iman Valiulahi , Sajad Daei , Farzan Haddadi , Farzad Parvaresh

The Fourier transforms of polyhedral cones can be used, via Brion's theorem, to compute various geometric quantities of polytopes, such as volumes, moments, and lattice-point counts. We present a novel method of computing these conic…

Combinatorics · Mathematics 2018-08-02 Quang-Nhat Le