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Related papers: Point Spread Function Estimation of Defocus

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Based on point spread function (PSF) engineering and astigmatism due to a pair of cylindrical lenses, a novel compressed imaging mechanism is proposed to achieve single-shot incoherent 3D imaging. The speckle-like PSF of the imaging system…

Optics · Physics 2021-05-24 Qiong Gao , Weidong Qu , Ming Shao , Wei Liu , Xiangzheng Cheng

Due to limited size and imperfect of the optical components in a spectrometer, aberration has inevitably been brought into two-dimensional multi-fiber spectrum image in LAMOST, which leads to obvious spacial variation of the point spread…

Instrumentation and Methods for Astrophysics · Physics 2020-10-28 Jiali Xu , Qian Yin , Ping Guo , Xin Zheng

Instrumental aberrations strongly limit high-contrast imaging of exoplanets, especially when they produce quasistatic speckles in the science images. With the help of recent advances in deep learning, we have developed in previous works an…

Instrumentation and Methods for Astrophysics · Physics 2022-11-14 Maxime Quesnel , Gilles Orban de Xivry , Olivier Absil , Gilles Louppe

Continuous wavefront sensing on future space telescopes allows relaxation of stability requirements while still allowing on-orbit diffraction-limited optical performance. We consider the suitability of phase retrieval to continuously…

Instrumentation and Methods for Astrophysics · Physics 2023-09-14 Hyukmo Kang , Kyle Van Gorkom , Jess Johnson , Ole Singlestad , Aaron Goldtooth , Daewook Kim , Ewan S. Douglas

Shape from Focus (SFF) is a depth reconstruction technique that estimates scene structure from focus variations observed across a focal stack, that is, a sequence of images captured at different focus settings. A key limitation of SFF…

Computer Vision and Pattern Recognition · Computer Science 2026-04-03 Khurram Ashfaq , Muhammad Tariq Mahmood

Image resolvability is the primary concern in imaging. This paper reports an estimation of the full width at half maximum of the point spread function from a Fourier domain plot of real sample images by neither using test objects, nor…

Context. Future weak lensing surveys, such as the Euclid mission, will attempt to measure the shapes of billions of galaxies in order to derive cosmological information. These surveys will attain very low levels of statistical error, and…

An accurate model of the point spread function is required in order to estimate positions and brightnesses of stars in digitized images. The PSF of the Gaia space telescope is unusual due to the use of drift-scan mode and time-delayed…

Instrumentation and Methods for Astrophysics · Physics 2026-04-08 Nicholas Rowell , Michael Davidson , Nigel C. Hambly , Lennart Lindegren , Javier Castañeda , Claus Fabricius , Jose Hernández , Dafydd W. Evans

The problem of image blurring is one of the most studied topics in the field of image processing. Image blurring is caused by various factors such as hand or camera shake. To restore the blurred image, it is necessary to know information…

Computer Vision and Pattern Recognition · Computer Science 2023-10-03 M. Zarebnia , R. Parvaz

In this second paper in a series dedicated to developing efficient numerical techniques for the deblurring Cosmic Microwave Background (CMB) maps, we consider the case of asymmetric point spread functions (PSF). Although conceptually this…

Astrophysics · Physics 2009-11-10 R. Vio , J. G. Nagy , L. Tenorio , P. Andreani , C. Baccigalupi , W. Wamsteker

We propose a new point-spread function (PSF) deconvolution algorithm for images of galaxies hosting an active galactic nucleus (AGN), designed to simultaneously enhance the spatial resolution of the host galaxy and remove the bright central…

Astrophysics of Galaxies · Physics 2026-05-15 Ren Kawase , Takatoshi Shibuya , Kazunori Matsuda

We present a theoretical analysis of the measuring algorithm we use when applying the Diffracto-Astrometry technique to Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) saturated stellar images. Theoretical Point Spread…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 A. Ruelas-Mayorga , L. J. Sanchez , J. Olivares , C. Allen , A. Poveda , R. Costero , A. Nigoche-Netro

Modern Giant Segmented Mirror Telescopes (GSMTs) like the Extremely Large Telescope, which is currently under construction, depend heavily on Adaptive Optics (AO) systems to correct for atmospheric distortions. However, a residual blur…

Instrumentation and Methods for Astrophysics · Physics 2023-07-05 Roland Wagner , Jenny Niebsch , Ronny Ramlau

Single-shot volumetric fluorescence (SVF) imaging offers a significant advantage over traditional imaging methods that require scanning across multiple axial planes as it can capture biological processes with high temporal resolution. The…

The Mid Infra Red Instrument (MIRI) is one of the four instruments onboard the James Webb Space Telescope (JWST), providing imaging, coronagraphy and spectroscopy over the 5-28 microns band. To verify the optical performance of the…

The ability to accurately measure the shapes of faint objects in images taken with the Advanced Camera for Surveys(ACS) on the Hubble Space Telescope (HST) depends upon detailed knowledge of the Point Spread Function (PSF). We show that…

We propose a learning-based depth from focus/defocus (DFF), which takes a focal stack as input for estimating scene depth. Defocus blur is a useful cue for depth estimation. However, the size of the blur depends on not only scene depth but…

Computer Vision and Pattern Recognition · Computer Science 2022-03-01 Yuki Fujimura , Masaaki Iiyama , Takuya Funatomi , Yasuhiro Mukaigawa

In this paper we study the high-dimensional super-resolution imaging problem. Here we are given an image of a number of point sources of light whose locations and intensities are unknown. The image is pixelized and is blurred by a known…

Optimization and Control · Mathematics 2022-10-19 Bakytzhan Kurmanbek , Elina Robeva

Multi-focus image fusion is a technique for obtaining an all-in-focus image in which all objects are in focus to extend the limited depth of field (DoF) of an imaging system. Different from traditional RGB-based methods, this paper presents…

Computer Vision and Pattern Recognition · Computer Science 2018-06-06 Hang Liu , Hengyu Li , Jun Luo , Shaorong Xie , Yu Sun

The imaging sharpness of an X-ray telescope is chiefly determined by the optical quality of its focusing optics, which in turn mostly depends on the shape accuracy and the surface finishing of the grazing-incidence X-ray mirrors that…

Instrumentation and Methods for Astrophysics · Physics 2014-12-10 Lorenzo Raimondi , Daniele Spiga