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Ultrasound is widely used in medical diagnostics allowing for accessible and powerful imaging but suffers from resolution limitations due to diffraction and the finite aperture of the imaging system, which restricts diagnostic use. The…

Computer Vision and Pattern Recognition · Computer Science 2024-08-08 Felix Duelmer , Walter Simson , Mohammad Farid Azampour , Magdalena Wysocki , Angelos Karlas , Nassir Navab

We present a method for speckle holography that is optimised for crowded fields. Its two key features are an iterativ improvement of the instantaneous Point Spread Functions (PSFs) extracted from each speckle frame and the (optional)…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 R. Schoedel , S. Yelda , A. Ghez , J. H. V. Girard , L. Labadie , R. Rebolo , A. Perez-Garrido , M. R. Morris

High quality, repeatable point-spread functions are important for science cases like direct exoplanet imaging, high-precision astrometry, and high-resolution spectroscopy of exoplanets. For such demanding applications, the initial on-sky…

Instrumentation and Methods for Astrophysics · Physics 2021-07-19 Steven P. Bos , Michael Bottom , Sam Ragland , Jacques-Robert Delorme , Sylvain Cetre , Laurent Pueyo

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

The study of astronomical phenomena through ground-based observations is always challenged by the distorting effects of Earth's atmosphere. Traditional methods of post-facto image correction, essential for correcting these distortions,…

Instrumentation and Methods for Astrophysics · Physics 2024-08-14 A. Asensio Ramos

The ill-posed problem of phase retrieval in optics, using one or more intensity measurements, has a multitude of applications using electromagnetic or matter waves. Many phase retrieval algorithms are computed on pixel arrays using discrete…

Image and Video Processing · Electrical Eng. & Systems 2022-09-21 J. A. Pollock , K. S. Morgan , L. C. P. Croton , M. K. Croughan , G. Ruben , N. Yagi , H. Sekiguchi , M. J. Kitchen

A Semi-supervised Segmentation Fusion algorithm is proposed using consensus and distributed learning. The aim of Unsupervised Segmentation Fusion (USF) is to achieve a consensus among different segmentation outputs obtained from different…

Computer Vision and Pattern Recognition · Computer Science 2015-02-27 Mete Ozay

Neural posterior estimation (NPE), a type of amortized variational inference, is a computationally efficient means of constructing probabilistic catalogs of light sources from astronomical images. To date, NPE has not been used to perform…

Instrumentation and Methods for Astrophysics · Physics 2025-08-26 Aakash Patel , Tianqing Zhang , Camille Avestruz , Jeffrey Regier , the LSST Dark Energy Science Collaboration

In the case of ground-based telescopes equipped with adaptive optics systems, the point spread function (PSF) is only poorly known or completely unknown. Moreover, an accurate modeling of the PSF is in general not available. Therefore in…

Numerical Analysis · Mathematics 2015-06-09 M. Prato , A. La Camera , S. Bonettini , S. Rebegoldi , M. Bertero , P. Boccacci

We have developed a novel method for co-adding multiple under-sampled images that combines the iteratively reweighted least squares and divide-and-conquer algorithms. Our approach not only allows for the anti-aliasing of the images but also…

Instrumentation and Methods for Astrophysics · Physics 2024-02-29 Lei Wang , Huanyuan Shan , Lin Nie , Dezi Liu , Zhaojun Yan , Guoliang Li , Cheng Cheng , Yushan Xie , Han Qu , Wenwen Zheng , Xi Kang

We study the problem of deconvolution for light-sheet microscopy, where the data is corrupted by spatially varying blur and a combination of Poisson and Gaussian noise. The spatial variation of the point spread function (PSF) of a…

Point spread function (PSF) reconstruction (PSF-R) is a well established technique to determine reliably and accurately the PSF from Adaptive Optics (AO) control loop data. We have successfully applied this technique to improve the…

Instrumentation and Methods for Astrophysics · Physics 2020-04-15 Olivier Beltramo-Martin , Antonino Marasco , Thierry Fusco , Davide Massari , Julien Milli , Giuliana Fiorentino , B. Neichel

A main science goal for the Large Synoptic Survey Telescope (LSST) is to measure the cosmic shear signal from weak lensing to extreme accuracy. One difficulty, however, is that with the short exposure time ($\simeq$15 seconds) proposed, the…

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

We investigate the utility of meta-optical encoders for generalizable image compression by leveraging their intrinsic shift-invariant point spread functions (PSFs). Compared with purely digital approaches, such optical encoders offer…

Optics · Physics 2026-02-23 Yubo Zhang , Rui Chen , Zhihao Zhou , Arka Majumdar

An undersampled point spread function may interact with the microstructure of a solid-state detector such that the total flux detected can depend sensitively on where the PSF center falls within a pixel. Such intra-pixel sensitivity…

Astrophysics · Physics 2009-10-31 Tod R. Lauer

A robust and extended characterization of the point spread function (PSF) is crucial to extract the photometric information produced by deep imaging surveys. Here, we present the extended PSFs of the Sloan Digital Sky Survey (SDSS), one of…

Instrumentation and Methods for Astrophysics · Physics 2020-01-28 Raúl Infante-Sainz , Ignacio Trujillo , Javier Román

The point spread function (PSF) of a translation invariant imaging system is its impulse response, which cannot always be measured directly. This is the case in high energy X-ray radiography, and it must be estimated from images of…

Numerical Analysis · Mathematics 2017-09-27 Kevin T. Joyce , Johnathan M. Bardsley , Aaron Luttman

The optics of any camera degrades the sharpness of photographs, which is a key visual quality criterion. This degradation is characterized by the point-spread function (PSF), which depends on the wavelengths of light and is variable across…

Image and Video Processing · Electrical Eng. & Systems 2022-08-02 Thomas Eboli , Jean-Michel Morel , Gabriele Facciolo

We explore the impact of aperture size and shape on automotive camera systems for deep-learning-based tasks like traffic sign recognition and light state detection. A method is proposed to simulate optical effects using the point spread…

Computer Vision and Pattern Recognition · Computer Science 2025-01-17 Ofer Bar-Shalom , Tzvi Philipp , Eran Kishon
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