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Related papers: Geometric Invariants for Sparse Unknown View Tomog…

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In computed tomography, data consist of measurements of the attenuation of X-rays passing through an object. The goal is to reconstruct the linear attenuation coefficient of the object's interior. For each position of the X-ray source,…

In this paper, we present an algorithm for effectively reconstructing an object from a set of its tomographic projections without any knowledge of the viewing directions or any prior structural information, in the presence of pathological…

Image and Video Processing · Electrical Eng. & Systems 2018-11-13 Ritwick Chaudhry , Arunabh Ghosh , Ajit Rajwade

We present a means of formulating and solving the well known structure-and-motion problem in computer vision with probabilistic graphical models. We model the unknown camera poses and 3D feature coordinates as well as the observed 2D…

Computer Vision and Pattern Recognition · Computer Science 2021-10-11 Simon Streicher , Willie Brink , Johan du Preez

Estimating positions of world points from features observed in images is a key problem in 3D reconstruction, image mosaicking,simultaneous localization and mapping and structure from motion. We consider a special instance in which there is…

Computer Vision and Pattern Recognition · Computer Science 2018-02-27 Cheng Peng , Volkan Isler

We consider geometry parameter estimation in industrial sawmill fan-beam X-ray tomography. In such industrial settings, scanners do not always allow identification of the location of the source-detector pair, which creates the issue of…

Computational Engineering, Finance, and Science · Computer Science 2023-12-11 Angelina Senchukova , Jarkko Suuronen , Jere Heikkinen , Lassi Roininen

The reconstruction of an object's shape or surface from a set of 3D points plays an important role in medical image analysis, e.g. in anatomy reconstruction from tomographic measurements or in the process of aligning intra-operative…

Computer Vision and Pattern Recognition · Computer Science 2017-02-16 Florian Bernard , Luis Salamanca , Johan Thunberg , Alexander Tack , Dennis Jentsch , Hans Lamecker , Stefan Zachow , Frank Hertel , Jorge Goncalves , Peter Gemmar

This paper considers the inverse problem of identifying the source term of parabolic equations from sparse boundary measurements. We used data from moving sensors to locate the unknown source term. This work first proves the uniqueness of…

Analysis of PDEs · Mathematics 2026-04-14 Qiling Gu , Wenlong Zhang , Zhidong Zhang

In tomographic reconstruction, the goal is to reconstruct an unknown object from a collection of line integrals. Given a complete sampling of such line integrals for various angles and directions, explicit inverse formulas exist to…

Numerical Analysis · Mathematics 2018-01-18 Tristan van Leeuwen , Simon Maretzke , K. Joost Batenburg

The inverse problem of identifying the unknown spacewise dependent source F(x) in 1D wave equation is considered. Measured data are taken in the form g(t) := u(0; t). The relationship between that problem and Ground Penetrating Radar (GRR)…

Numerical Analysis · Mathematics 2016-09-14 Balgaisha Mukanova , Vladimir G. Romanov

We propose a method for predicting the 3D shape of a deformable surface from a single view. By contrast with previous approaches, we do not need a pre-registered template of the surface, and our method is robust to the lack of texture and…

Computer Vision and Pattern Recognition · Computer Science 2018-09-28 Albert Pumarola , Antonio Agudo , Lorenzo Porzi , Alberto Sanfeliu , Vincent Lepetit , Francesc Moreno-Noguer

Blind inverse problems in imaging arise from uncertainties in the system used to collect (noisy) measurements of images. Recovering clean images from these measurements typically requires identifying the imaging system, either implicitly or…

Image and Video Processing · Electrical Eng. & Systems 2025-03-28 Brett Levac , Ajil Jalal , Kannan Ramchandran , Jonathan I. Tamir

In this paper, we introduce a novel numerical method for reconstructing the trajectory within three-dimensional space, where both the emission moment and spatial location of the point source are unknown. Our approach relies solely on…

Numerical Analysis · Mathematics 2025-07-29 Guanqiu Ma , Haonan Zhang , Hongxia Guo

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

In this work, we present and investigate the novel blind inverse problem of position-blind ptychography, i.e., ptychographic phase retrieval without any knowledge of scan positions, which then must be recovered jointly with the image. The…

Image and Video Processing · Electrical Eng. & Systems 2026-03-18 Simon Welker , Lorenz Kuger , Tim Roith , Berthy Feng , Martin Burger , Timo Gerkmann , Henry Chapman

A two-dimensional tomographic problem is studied. The target is assumed to be a homogeneous object bounded by a smooth curve. A Non Uniform Rational Basis Splines (NURBS) curve is used as computational representation of the boundary. This…

Numerical Analysis · Mathematics 2017-08-08 Heikki Haario , Aki Kallonen , Marko Laine , Esa Niemi , Zenith Purisha , Samuli Siltanen

Computational image reconstruction algorithms generally produce a single image without any measure of uncertainty or confidence. Regularized Maximum Likelihood (RML) and feed-forward deep learning approaches for inverse problems typically…

Machine Learning · Computer Science 2020-12-18 He Sun , Katherine L. Bouman

The reconstruction of X-rays CT images from sparse or limited-angle geometries is a highly challenging task. The lack of data typically results in artifacts in the reconstructed image and may even lead to object distortions. For this…

Computer Vision and Pattern Recognition · Computer Science 2026-02-12 Davide Evangelista , Pasquale Cascarano , Elena Loli Piccolomini

In this work, we derive a model for the covariance of the visual residuals in multi-view SfM, odometry and SLAM setups. The core of our approach is the formulation of the residual covariances as a combination of geometric and photometric…

Computer Vision and Pattern Recognition · Computer Science 2022-02-03 Alejandro Fontan , Laura Oliva , Javier Civera , Rudolph Triebel

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

In this paper we investigate the problem of inducing a distribution over three-dimensional structures given two-dimensional views of multiple objects taken from unknown viewpoints. Our approach called "projective generative adversarial…

Computer Vision and Pattern Recognition · Computer Science 2016-12-20 Matheus Gadelha , Subhransu Maji , Rui Wang