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Fitting concentric geometric objects to digitized data is an important problem in many areas such as iris detection, autonomous navigation, and industrial robotics operations. There are two common approaches to fitting geometric shapes to…

Computer Vision and Pattern Recognition · Computer Science 2021-03-10 Ali A. Al-Sharadqah , Lorenzo Rull

The study of parameter-dependent partial differential equations (parametric PDEs) with countably many parameters has been actively studied for the last few decades. In particular, it has been well known that a certain type of parametric…

Numerical Analysis · Mathematics 2025-02-10 Byeong-Ho Bahn

A new variational approach to solve the problem of estimating the (possibly discontinuous) coefficient functions $p$, $q$ and $f$ in elliptic equations of the form $-\nabla \cdot (p(x)\nabla u) + \lambda q(x) u = f$, $x \in \Omega \subset…

Numerical Analysis · Mathematics 2020-08-07 Abinash Nayak

Over the years many ellipse detection algorithms spring up and are studied broadly, while the critical issue of detecting ellipses accurately and efficiently in real-world images remains a challenge. In this paper, we propose a valuable…

Computer Vision and Pattern Recognition · Computer Science 2019-08-06 Changsheng Lu , Siyu Xia , Ming Shao , Yun Fu

Problems in differentiable rendering often involve optimizing scene parameters that cause motion in image space. The gradients for such parameters tend to be sparse, leading to poor convergence. While existing methods address this sparsity…

Graphics · Computer Science 2025-03-31 Ishit Mehta , Manmohan Chandraker , Ravi Ramamoorthi

Many man-made objects are characterised by a shape that is symmetric along one or more planar directions. Estimating the location and orientation of such symmetry planes can aid many tasks such as estimating the overall orientation of an…

Computer Vision and Pattern Recognition · Computer Science 2021-07-01 Mihaela Cătălina Stoian , Tommaso Cavallari

Few-shot image classification learns to recognize new categories from limited labelled data. Metric learning based approaches have been widely investigated, where a query sample is classified by finding the nearest prototype from the…

Computer Vision and Pattern Recognition · Computer Science 2021-06-04 Zhizheng Zhang , Cuiling Lan , Wenjun Zeng , Zhibo Chen , Shih-Fu Chang

We demonstrate how one can choose the smoothing parameter in image denoising by a statistical multiresolution criterion, both globally and locally. Using inhomogeneous diffusion and total variation regularization as examples for localized…

Methodology · Statistics 2010-02-01 Thomas Hotz , Philipp Marnitz , Rahel Stichtenoth , Laurie Davies , Zakhar Kabluchko , Axel Munk

We consider finite element approximations of ill-posed elliptic problems with conditional stability. The notion of {\emph{optimal error estimates}} is defined including both convergence with respect to mesh parameter and perturbations in…

Numerical Analysis · Mathematics 2024-03-25 Erik Burman , Mihai Nechita , Lauri Oksanen

This paper studies the problems of identifiability and estimation in high-dimensional nonparametric latent structure models. We introduce an identifiability theorem that generalizes existing conditions, establishing a unified framework…

Statistics Theory · Mathematics 2025-08-06 Yichen Lyu , Pengkun Yang

As one of the most commonly seen data challenges, missing data, in particular, multiple, non-monotone missing patterns, complicates estimation and inference due to the fact that missingness mechanisms are often not missing at random, and…

Methodology · Statistics 2025-04-21 Jianing Dong , Raymond K. W. Wong , Kwun Chuen Gary Chan

Crucial information barely visible to the human eye is often embedded in a series of low-resolution images taken of the same scene. Super-resolution enables the extraction of this information by reconstructing a single image, at a high…

Computer Vision and Pattern Recognition · Computer Science 2011-12-08 S. S. Panda , M. S. R. S Prasad , G. Jena

To produce images that are suitable for display, tone-mapping is widely used in digital cameras to map linear color measurements into narrow gamuts with limited dynamic range. This introduces non-linear distortion that must be undone,…

Computer Vision and Pattern Recognition · Computer Science 2014-11-11 Ayan Chakrabarti , Ying Xiong , Baochen Sun , Trevor Darrell , Daniel Scharstein , Todd Zickler , Kate Saenko

In this paper, we observe a fixed number of unknown $2\pi$-periodic functions differing from each other by both phases and amplitude. This semiparametric model appears in literature under the name "shape invariant model." While the common…

Statistics Theory · Mathematics 2010-10-06 Myriam Vimond

This article is a review on basic concepts and tools devoted to a posteriori error estimation for problems solved with the Finite Element Method. For the sake of simplicity and clarity, we mostly focus on linear elliptic diffusion problems,…

Numerical Analysis · Mathematics 2021-10-06 Ludovic Chamoin , Frederic Legoll

Parameter inference with an estimated covariance matrix systematically loses information due to the remaining uncertainty of the covariance matrix. Here, we quantify this loss of precision and develop a framework to hypothetically restore…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-16 Elena Sellentin , Alan F. Heavens

Calibration of devices with different modalities is a key problem in robotic vision. Regular spatial objects, such as planes, are frequently used for this task. This paper deals with the automatic detection of ellipses in camera images, as…

Computer Vision and Pattern Recognition · Computer Science 2020-02-25 Levente Hajder , Tekla Tóth , Zoltán Pusztai

In the context of unfitted finite element discretizations the realization of high order methods is challenging due to the fact that the geometry approximation has to be sufficiently accurate. We consider a new unfitted finite element method…

Numerical Analysis · Mathematics 2017-06-27 Christoph Lehrenfeld , Arnold Reusken

We present a method to estimate lighting from a single image of an indoor scene. Previous work has used an environment map representation that does not account for the localized nature of indoor lighting. Instead, we represent lighting as a…

Computer Vision and Pattern Recognition · Computer Science 2019-10-22 Marc-André Gardner , Yannick Hold-Geoffroy , Kalyan Sunkavalli , Christian Gagné , Jean-François Lalonde

Reactive sputtering is a plasma-based technique to deposit a thin film on a substrate. This contribution presents a novel parameter-interval estimation method for a well-established model that describes the uncertain and nonlinear reactive…

Systems and Control · Electrical Eng. & Systems 2026-03-27 Fabian Schneider , Christian Wölfel