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Generalized Abel equations have been employed in the recent literature to invert Radon transforms which arise in a number of important imaging applications, including Compton Scatter Tomography (CST), Ultrasound Reflection Tomography (URT),…

Functional Analysis · Mathematics 2023-06-16 James W. Webber

We study numerical methods of tomography in domains with a reflecting obstacle. It will be shown that tomography with sets containing both broken rays, i.e. rays reflecting at the obstacle, as well as unbroken rays, has a smaller error…

Numerical Analysis · Mathematics 2012-02-14 Kamen Lozev

Two algorithms are introduced for the computation of discrete integral transforms with a multiscale approach operating in discrete three-dimensional (3D) volumes while considering its real-time implementation. The first algorithm, referred…

The recent application of Fourier Based Iterative Reconstruction Method (FIRM) has made it possible to achieve high-quality 2D images from a fan beam Computed Tomography (CT) scan with a limited number of projections in a fast manner. The…

Image and Video Processing · Electrical Eng. & Systems 2020-06-24 N. Teyfouri , H. Rabbani , R. Kafieh , Iraj Jabbari

Inverse problems, such as accelerated MRI reconstruction, are ill-posed and an infinite amount of possible and plausible solutions exist. This may not only lead to uncertainty in the reconstructed image but also in downstream tasks such as…

Image and Video Processing · Electrical Eng. & Systems 2024-07-26 Jan Nikolas Morshuis , Matthias Hein , Christian F. Baumgartner

Recently, experiments have been reported where researchers were able to perform high dynamic range (HDR) tomography in a heuristic fashion, by fusing multiple tomographic projections. This approach to HDR tomography has been inspired by HDR…

Information Theory · Computer Science 2021-05-11 Matthias Beckmann , Ayush Bhandari , Felix Krahmer

We study a new class of Radon transforms defined on circular cones called the conical Radon transform. In $\mathbb{R}^3$ it maps a function to its surface integrals over circular cones, and in $\mathbb{R}^2$ it maps a function to its…

Numerical Analysis · Mathematics 2015-06-17 Rim Gouia-Zarrad , Gaik Ambartsoumian

Digital array orthogonal transformations that can be presented as a decomposition over basis items or basis images are considered. The orthogonal transform provides digital data scattering, a process of pixel energy redistributing, that is…

Multimedia · Computer Science 2019-01-24 V. N. Gorbachev , L. A. Denisov , E. M. Kaynarova , I. K. Metelev , E. S. Yakovleva

Ray tracing algorithms, that can simulate multipath radio propagation in presence of geometric obstacles such as buildings, objects or vehicles, are becoming quite popular, due to the increasing availability of digital environment databases…

Signal Processing · Electrical Eng. & Systems 2023-06-14 Denis Bilibashi , Enrico M. Vitucci , Vittorio Degli-Esposti

Using integral transforms to the end of lines detection in images with complex background, makes the detection a hard task needing additional processing to manage the detection. As an integral transform, the Scale Space Radon Transform…

Computer Vision and Pattern Recognition · Computer Science 2023-11-16 Aicha Baya Goumeidane , Djemel Ziou , Nafaa Nacereddine

Consider the incidence of a time-harmonic electromagnetic plane wave onto a biperiodic dielectric grating, where the surface is assumed to be a small and smooth perturbation of a plane. The diffraction is modeled as a transmission problem…

Numerical Analysis · Mathematics 2017-08-02 Xue Jiang , Peijun Li

The graph fractional Fourier transform (GFRFT) for unitary graph Fourier transform (GFT) matrices can be interpreted through the scalar function $e^{j\alpha\theta}$ on the unit circle. Under the principal branch, its Fourier-series…

Signal Processing · Electrical Eng. & Systems 2026-05-19 Ziqi Yan , Mingzhi Wang , Sen Shi , Feiyue Zhao , Manjun Cui , Yangfan He , Zhichao Zhang

An exact inversion formula for the Lorentz integral transform (LIT) is provided together with the spectrum of the LIT kernel. The exponential increase of the inverse Fourier transform of the LIT kernel entering the inversion formula…

Nuclear Theory · Physics 2009-11-13 W. Gloeckle , M. Schwamb

In many physical systems, inputs related by intrinsic system symmetries are mapped to the same output. When inverting such systems, i.e., solving the associated inverse problems, there is no unique solution. This causes fundamental…

Machine Learning · Computer Science 2020-03-23 Kshitij Tayal , Chieh-Hsin Lai , Vipin Kumar , Ju Sun

A ray-tracing (RT) enhanced back-projection algorithm (RT-BPA) for microwave imaging in multipath environments is presented. By tightly incorporating the concept of ray-tracing into a generalized version of traditional BPA, this method…

Image and Video Processing · Electrical Eng. & Systems 2026-05-12 Han Na , Quanfeng Wang , Matthias Saurer , Meisong Tong , Thomas F. Eibert

The bispectral problem is motivated by an effort to understand and extend a remarkable phenomenon in Fourier analysis on the real line: the operator of time-and-band limiting is an integral operator admitting a second-order differential…

Functional Analysis · Mathematics 2022-02-02 F. Alberto Grünbaum , Brian D. Vasquez , Jorge P. Zubelli

Moment methods to reconstruct images from their Radon transforms are both natural and useful. They can be used to suppress noise or other spurious effects and can lead to highly efficient reconstructions from relatively few projections. We…

Functional Analysis · Mathematics 2019-03-08 H. Choi , V. Ginting , F. Jafari , R. Mnatsakanov

Blind ptychography is a phase retrieval method using multiple coded diffraction patterns from different, overlapping parts of the unknown extended object illuminated with an unknown window function. The window function is also known as the…

Image and Video Processing · Electrical Eng. & Systems 2018-12-04 Albert Fannjiang

For a general complex scattering potential defined on a real line, we show that the equations governing invisibility of the potential are invariant under the combined action of parity and time-reversal (PT) transformation. We determine the…

Mathematical Physics · Physics 2013-03-12 Ali Mostafazadeh

Given a bounded $C^1$ domain $\Omega\subset\R^n$ and a nonempty subset $E$ of its boundary (set of tomography), we consider broken rays which start and end at points of $E$. We ask: If the integrals of a function over all such broken rays…

Mathematical Physics · Physics 2013-03-07 Joonas Ilmavirta
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