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Related papers: Geometry parameter estimation for sparse X-ray log…

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This work applies Bayesian experimental design to selecting optimal projection geometries in (discretized) parallel beam X-ray tomography assuming the prior and the additive noise are Gaussian. The introduced greedy exhaustive optimization…

Numerical Analysis · Mathematics 2021-08-11 Martin Burger , Andreas Hauptmann , Tapio Helin , Nuutti Hyvönen , Juha-Pekka Puska

Within the calibration of material models, often the numerical results of a simulation model $y$ are compared with the experimental measurements $y^*$. Usually, the differences between measurements and simulation are minimized using least…

Materials Science · Physics 2024-08-14 Thomas Most

Precise calibration is a must for high reliance 3D computer vision algorithms. A challenging case is when the camera is behind a protective glass or transparent object: due to refraction, the image is heavily distorted; the pinhole camera…

Computer Vision and Pattern Recognition · Computer Science 2019-09-25 Szabolcs Pável , Csanád Sándor , Lehel Csató

Computer simulation models are widely used to study complex physical systems. A related fundamental topic is the inverse problem, also called calibration, which aims at learning about the values of parameters in the model based on…

Methodology · Statistics 2024-01-03 Yang Li , Shifeng Xiong

We investigate the problem of estimating the 3D shape of an object defined by a set of 3D landmarks, given their 2D correspondences in a single image. A successful approach to alleviating the reconstruction ambiguity is the 3D deformable…

Computer Vision and Pattern Recognition · Computer Science 2017-01-12 Xiaowei Zhou , Menglong Zhu , Spyridon Leonardos , Kostas Daniilidis

The diagnostic quality of computed tomography (CT) scans is usually restricted by the induced patient dose, scan speed, and image quality. Sparse-angle tomographic scans reduce radiation exposure and accelerate data acquisition, but suffer…

Computer Vision and Pattern Recognition · Computer Science 2023-08-10 Fabian Wagner , Mareike Thies , Noah Maul , Laura Pfaff , Oliver Aust , Sabrina Pechmann , Christopher Syben , Andreas Maier

The parameter fit from a model grid is limited by our capability to reduce the number of models, taking into account the number of parameters and the non linear variation of the models with the parameters. The Local MultiLinear Regression…

Astrophysics · Physics 2009-11-13 A. Bijaoui , A. Recio-Blanco , P. de Laverny

Gaussian graphical models are used for determining conditional relationships between variables. This is accomplished by identifying off-diagonal elements in the inverse-covariance matrix that are non-zero. When the ratio of variables (p) to…

Applications · Statistics 2018-08-07 Donald R. Williams , Juho Piironen , Aki Vehtari , Philippe Rast

A convex optimization based method is proposed for quantum process tomography, in the case of known channel model structure, but unknown channel parameters. The main idea is to select an affine parametrization of the Choi matrix as a set of…

Quantum Physics · Physics 2010-04-30 Gábor Balló , Katalin M. Hangos

Surface roughness is an important quantity to many engineering and precision manufacturing disciplines. In this paper we investigate the problem of estimating the root-mean-square roughness of a sample by passive linear optical methods. By…

We propose new compressive parameter estimation algorithms that make use of polar interpolation to improve the estimator precision. Our work extends previous approaches involving polar interpolation for compressive parameter estimation in…

Information Theory · Computer Science 2016-11-17 Karsten Fyhn , Marco F. Duarte , Søren Holdt Jensen

We tackle the problem of automatic calibration of radially distorted cameras in challenging conditions. Accurately determining distortion parameters typically requires either 1) solving the full Structure from Motion (SfM) problem involving…

Computer Vision and Pattern Recognition · Computer Science 2025-09-16 Daniil Sinitsyn , Linus Härenstam-Nielsen , Daniel Cremers

In this paper we analyze several strategies for the estimation of the roughness parameter of the $\mathcal G_I^0$ distribution. It has been shown that this distribution is able to characterize a large number of targets in monopolarized SAR…

Information Theory · Computer Science 2016-11-17 Juliana Gambini , Julia Cassetti , María Magdalena Lucini , Alejandro C. Frery

We consider an important class of signal processing problems where the signal of interest is known to be sparse, and can be recovered from data given auxiliary information about how the data was generated. For example, a sparse Green's…

Optimization and Control · Mathematics 2012-12-06 Aleksandr Y. Aravkin , Tristan van Leeuwen , Ning Tu

Linear inverse problems are very common in signal and image processing. Many algorithms that aim at solving such problems include unknown parameters that need tuning. In this work we focus on optimally selecting such parameters in iterative…

Computer Vision and Pattern Recognition · Computer Science 2010-03-23 Raja Giryes , Michael Elad , Yonina C Eldar

Different technical and physical factors may affect the image quality reconstructed using a Computed Tomography system. We have developed and designed a 2D Gamma Computed Tomography set up to study the effect of some physical parameters.…

Instrumentation and Detectors · Physics 2022-08-19 Kajal Kumari , Mayank Goswami

Planar homography, with eight degrees of freedom (DOFs), is fundamental in numerous computer vision tasks. While the positional offsets of four corners are widely adopted (especially in neural network predictions), this parameterization…

Computer Vision and Pattern Recognition · Computer Science 2025-05-26 Yao Huang , Si-Yuan Cao , Yaqing Ding , Hao Yin , Shibin Xie , Shuting Wang , Zhijun Fang , Jiachun Wang , Shen Cai , Junchi Yan , Shuhan Shen

Scatterometry is a fast, indirect and nondestructive optical method for the quality control in the production of lithography masks. Geometry parameters of line gratings are obtained from diffracted light intensities by solving an inverse…

Data Analysis, Statistics and Probability · Physics 2019-11-01 Nando Farchmin , Martin Hammerschmidt , Philipp-Immanuel Schneider , Matthias Wurm , Bernd Bodermann , Markus Bär , Sebastian Heidenreich

Iterative methods for fitting a Gaussian Random Field (GRF) model via maximum likelihood (ML) estimation requires solving a nonconvex optimization problem. The problem is aggravated for anisotropic GRFs where the number of covariance…

Machine Learning · Statistics 2021-01-12 Sam Davanloo Tajbakhsh , Necdet Serhat Aybat , Enrique Del Castillo

The ability to obtain reliable point estimates of model parameters is of crucial importance in many fields of physics. This is often a difficult task given that the observed data can have a very high number of dimensions. In order to…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Janis Fluri , Aurelien Lucchi , Tomasz Kacprzak , Alexandre Refregier , Thomas Hofmann