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X-ray ptychography is one of the versatile techniques for nanometer resolution imaging. The magnitude of the diffraction patterns is recorded on a detector and the phase of the diffraction patterns is estimated using phase retrieval…

Image and Video Processing · Electrical Eng. & Systems 2021-05-21 Prasan Shedligeri , Florian Schiffers , Semih Barutcu , Pablo Ruiz , Aggelos K Katsaggelos , Oliver Cossairt

Plasma diagnostics often employ computerized tomography to estimate emissivity profiles from a finite, and often limited, number of line-integrated measurements. Decades of algorithmic refinement have brought considerable improvements, and…

Plasma Physics · Physics 2026-03-12 D. Hamm , C. Theiler , M. Simeoni , B. P. Duval , T. Debarre , L. Simons , J. R. Queralt

We study full Bayesian procedures for high-dimensional linear regression under sparsity constraints. The prior is a mixture of point masses at zero and continuous distributions. Under compatibility conditions on the design matrix, the…

Statistics Theory · Mathematics 2015-10-15 Ismaël Castillo , Johannes Schmidt-Hieber , Aad van der Vaart

Recent literature provides many computational and modeling approaches for covariance matrices estimation in a penalized Gaussian graphical models but relatively little study has been carried out on the choice of the tuning parameter. This…

Methodology · Statistics 2009-09-08 Heng Lian

We consider the iterative reconstruction of both the internal geometry and the values of an inhomogeneous acoustic refraction index through a piecewise constant approximation. In this context, we propose two enhancements intended to reduce…

Numerical Analysis · Mathematics 2015-06-15 Yann Grisel , Jean-Pierre Raymond , Pierre-Alain Mazet , Vincent Mouysset

The parameters of a linear compartment model are usually estimated from experimental input-output data. A problem arises when infinitely many parameter values can yield the same result; such a model is called unidentifiable. In this case,…

Combinatorics · Mathematics 2016-03-08 Jasmijn A. Baaijens , Jan Draisma

We use tools from geometric statistics to analyze the usual estimation procedure of a template shape. This applies to shapes from landmarks, curves, surfaces, images etc. We demonstrate the asymptotic bias of the template shape estimation…

Computer Vision and Pattern Recognition · Computer Science 2017-02-03 Nina Miolane , Susan Holmes , Xavier Pennec

A new method is proposed to get image features' geometric information. Using Gaussian as an input signal, a theoretical optimal solution to calculate feature's affine shape is proposed. Based on analytic result of a feature model, the…

Computer Vision and Pattern Recognition · Computer Science 2015-03-19 Xiaopeng Xu , Xiaochun Zhang

Geometric calibration of cameras and projectors is an essential step that must be performed before any imaging system can be used. There are many well-known geometric calibration methods for calibrating systems comprised of multiple…

Computer Vision and Pattern Recognition · Computer Science 2024-10-25 Tomislav Petkovic , Simone Gasparini , Tomislav Pribanic

The statistical properties of Synthetic Aperture Radar (SAR) image texture reveals useful target characteristics. It is well-known that these images are affected by speckle, and prone to contamination as double bounce and corner reflectors.…

Applications · Statistics 2018-10-02 Débora Chan , Andrea Rey , Juliana Gambini , Alejandro C. Frery

Predicting 3D shapes and poses of static objects from a single RGB image is an important research area in modern computer vision. Its applications range from augmented reality to robotics and digital content creation. Typically this task is…

Computer Vision and Pattern Recognition · Computer Science 2021-11-11 Florian Langer , Ignas Budvytis , Roberto Cipolla

This paper investigates the detection and estimation of a single change in high-dimensional linear models. We derive minimax lower bounds for the detection boundary and the estimation rate, which uncover a phase transition governed by the…

Statistics Theory · Mathematics 2026-02-11 Haeran Cho , Housen Li

The convergence rate is analyzed for the SpaSRA algorithm (Sparse Reconstruction by Separable Approximation) for minimizing a sum $f (\m{x}) + \psi (\m{x})$ where $f$ is smooth and $\psi$ is convex, but possibly nonsmooth. It is shown that…

Optimization and Control · Mathematics 2009-12-10 William Hager , Dzung Phan , Hongchao Zhang

Creating virtual models of real spaces and objects is cumbersome and time consuming. This paper focuses on the problem of geometric reconstruction from sparse data obtained from certain image-based modeling approaches. A number of elegant…

Computational Geometry · Computer Science 2010-03-19 Eleanor G. Rieffel , Don Kimber , Jim Vaughan

Determining the adsorption isotherms is an issue of significant importance in preparative chromatography. A modern technique for estimating adsorption isotherms is to solve an inverse problem so that the simulated batch separation coincides…

Applications · Statistics 2022-11-24 Jiaji Su , Zhigang Yao , Cheng Li , Ye Zhang

This paper addresses the problem of estimating the shape of objects that exhibit spatially-varying reflectance. We assume that multiple images of the object are obtained under a fixed view-point and varying illumination, i.e., the setting…

Computer Vision and Pattern Recognition · Computer Science 2016-09-22 Zhuo Hui , Aswin C Sankaranarayanan

Interferometers require accurate determination of the array configuration in order to produce reliable observations. A method is presented for finding the maximum-likelihood estimate of the telescope geometry, and of other instrumental…

Astrophysics · Physics 2009-11-07 Klaus Maisinger , M. P. Hobson , Richard D. E. Saunders , Keith J. B. Grainge

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

Parameter estimation is crucial for modeling, tracking, and control of complex dynamical systems. However, parameter uncertainties can compromise system performance under a controller relying on nominal parameter values. Typically,…

Robotics · Computer Science 2020-02-20 Mouhyemen Khan , Abhijit Chatterjee

Asymptotic lower bounds for estimation play a fundamental role in assessing the quality of statistical procedures. In this paper we propose a framework for obtaining semi-parametric efficiency bounds for sparse high-dimensional models,…

Statistics Theory · Mathematics 2017-10-16 Jana Jankova , Sara van de Geer