English
Related papers

Related papers: Stable radial distortion calibration by polynomial…

200 papers

Uncalibrated photometric stereo is proposed to estimate the detailed surface normal from images under varying and unknown lightings. Recently, deep learning brings powerful data priors to this underdetermined problem. This paper presents a…

Computer Vision and Pattern Recognition · Computer Science 2022-08-09 Fangzhou Gao , Meng Wang , Lianghao Zhang , Li Wang , Jiawan Zhang

Aims: To propose a method for the polarimetric calibration of large astronomical mirrors that does not require use of special optical devices nor knowledge of the exact polarization properties of the calibration target. Methods: We study…

Instrumentation and Methods for Astrophysics · Physics 2015-11-11 A. Lopez Ariste

Neural Radiance Fields (NeRF) can be optimized to obtain high-fidelity 3D scene reconstructions of objects and large-scale scenes. However, NeRFs require accurate camera parameters as input -- inaccurate camera parameters result in blurry…

Computer Vision and Pattern Recognition · Computer Science 2023-09-01 Keunhong Park , Philipp Henzler , Ben Mildenhall , Jonathan T. Barron , Ricardo Martin-Brualla

From the optimization point of view, a difficulty with parallel MRI with simultaneous coil sensitivity estimation is the multiplicative nature of the non-linear forward operator: the image being reconstructed and the coil sensitivities…

Numerical Analysis · Mathematics 2018-02-06 Yonggui Zhu , Tuomo Valkonen

In this paper we generalize the Interior Point-Proximal Method of Multipliers (IP-PMM) presented in [An Interior Point-Proximal Method of Multipliers for Convex Quadratic Programming, Computational Optimization and Applications, 78,…

Optimization and Control · Mathematics 2021-09-09 Spyridon Pougkakiotis , Jacek Gondzio

We introduce Sieve-SDP, a simple facial reduction algorithm to preprocess semidefinite programs (SDPs). Sieve-SDP inspects the constraints of the problem to detect lack of strict feasibility, deletes redundant rows and columns, and reduces…

Optimization and Control · Mathematics 2021-03-02 Yuzixuan , Zhu , Gabor Pataki , Quoc Tran-Dinh

Accurate measurement of images produced by electronic displays is critical for the evaluation of both traditional and computational displays. Traditional display measurement methods based on sparse radiometric sampling and fitting a model…

Graphics · Computer Science 2025-09-23 Yancheng Cai , Robert Wanat , Rafal Mantiuk

Non-stationary blind super-resolution is an extension of the traditional super-resolution problem, which deals with the problem of recovering fine details from coarse measurements. The non-stationary blind super-resolution problem appears…

Information Theory · Computer Science 2019-10-09 Shuang Li , Michael B. Wakin , Gongguo Tang

Radial correction distortion, applied by in-camera or out-camera software/firmware alters the supporting grid of the image so as to hamper PRNU-based camera attribution. Existing solutions to deal with this problem try to invert/estimate…

Computer Vision and Pattern Recognition · Computer Science 2024-04-15 Andrea Montibeller , Fernando Pérez-González

The task of camera calibration is to estimate the intrinsic and extrinsic parameters of a camera model. Though there are some restricted techniques to infer the 3-D information about the scene from uncalibrated cameras, effective camera…

Computer Vision and Pattern Recognition · Computer Science 2016-08-31 Lili Ma , YangQuan Chen , Kevin L. Moore

This paper tackles the task of uncalibrated photometric stereo for 3D object reconstruction, where both the object shape, object reflectance, and lighting directions are unknown. This is an extremely difficult task, and the challenge is…

Computer Vision and Pattern Recognition · Computer Science 2022-07-19 Junxuan Li , Hongdong Li

We introduce a new, integrated approach to uncalibrated photometric stereo. We perform 3D reconstruction of Lambertian objects using multiple images produced by unknown, directional light sources. We show how to formulate a single…

Computer Vision and Pattern Recognition · Computer Science 2017-02-03 Soumyadip Sengupta , Hao Zhou , Walter Forkel , Ronen Basri , Tom Goldstein , David W. Jacobs

Motion planning under uncertainty is essential for reliable robot operation. Despite substantial advances over the past decade, the problem remains difficult for systems with complex dynamics. Most state-of-the-art methods perform search…

Robotics · Computer Science 2020-06-01 Marcus Hoerger , Hanna Kurniawati , Alberto Elfes

Perspective distortion (PD) leads to substantial alterations in the shape, size, orientation, angles, and spatial relationships of visual elements in images. Accurately determining camera intrinsic and extrinsic parameters is challenging,…

Computer Vision and Pattern Recognition · Computer Science 2024-10-10 Meenakshi Subhash Chippa , Prakash Chandra Chhipa , Kanjar De , Marcus Liwicki , Rajkumar Saini

The non-orthogonality of algebraic polynomials of field coordinates traditionally used to model field-dependent corrections to astrometric measurements, gives rise to subtle adverse effects. In particular, certain field dependent…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Valeri V. Makarov , Daniel R. Veillette , Gregory S. Hennessy , Benjamin F. Lane

This Letter presents a novel structured light system model that effectively considers local lens distortion by pixel-wise rational functions. We leverage the stereo method for initial calibration and then estimate the rational model for…

Optics · Physics 2023-05-15 Raúl Vargas , Lenny A. Romero , Song Zhang , Andres G. Marrugo

We discuss how semidefinite programming can be used to determine the second-order density matrix directly through a variational optimization. We show how the problem of characterizing a physical or N -representable density matrix leads to…

Computational Physics · Physics 2011-10-27 Brecht Verstichel , Helen van Aggelen , Dimitri Van Neck , Paul W. Ayers , Patrick Bultinck

Polarimetric imaging has been applied in a growing number of applications in robotic vision (ex. underwater navigation, glare removal, de-hazing, object classification, and depth estimation). One can find on the market RGB Polarization…

Computer Vision and Pattern Recognition · Computer Science 2022-08-30 Joaquin Rodriguez , Lew Lew-Yan-Voon , Renato Martins , Olivier Morel

We present a highly efficient blind restoration method to remove mild blur in natural images. Contrary to the mainstream, we focus on removing slight blur that is often present, damaging image quality and commonly generated by small…

Computer Vision and Pattern Recognition · Computer Science 2021-05-18 Mauricio Delbracio , Ignacio Garcia-Dorado , Sungjoon Choi , Damien Kelly , Peyman Milanfar

Modern reconstruction methods for magnetic resonance imaging (MRI) exploit the spatially varying sensitivity profiles of receive-coil arrays as additional source of information. This allows to reduce the number of time-consuming…

Medical Physics · Physics 2017-09-12 Martin Uecker