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In multi-photon microscopy (MPM), a recent in-vivo fluorescence microscopy system, the task of image restoration can be decomposed into two interlinked inverse problems: firstly, the characterization of the Point Spread Function (PSF) and…

Image and Video Processing · Electrical Eng. & Systems 2024-11-08 Julien Ajdenbaum , Emilie Chouzenoux , Claire Lefort , Ségolène Martin , Jean-Christophe Pesquet

We present a new algorithm for estimating the Point Spread Function (PSF) in wide-field astronomical images with extreme source crowding. Robust and accurate PSF estimation in crowded astronomical images dramatically improves the fidelity…

Image and Video Processing · Electrical Eng. & Systems 2021-02-09 Brendt Wohlberg , Przemek Wozniak

We describe a rapid and direct method for regularizing, post-facto, the point-spread function (PSF) of a telescope or other imaging instrument, across its entire field of view. Imaging instruments in general blur point sources of light by…

Instrumentation and Methods for Astrophysics · Physics 2023-03-20 J. M. Hughes , C. E. DeForest , D. B. Seaton

In this study, we elaborate on the concept of scalable anomalous reflector (AR) to analyze the angular response, frequency response, and spatial scalability of a designed AR across a broad range of angles and frequencies. We utilize…

Signal Processing · Electrical Eng. & Systems 2024-07-25 Le Hao , Sravan K. R. Vuyyuru , Sergei A. Tretyakov , Markus Rupp , Risto Valkonen

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

Compton cameras are radiation detectors that provide spatial information on the origin of the {\gamma}-ray sources based on the Compton scattering effect. Many applications require these detectors to be used at high counting rate. As such,…

Imaging is a crucial sensing function that finds wide applications in environmental reconstruction, autonomous driving, etc. However, the signal processing methods for existing radio imaging techniques, such as millimeter wave (mmWave)…

Signal Processing · Electrical Eng. & Systems 2026-04-02 Yanmo Hu , Shuowen Zhang , Ross Murch , Liang Liu

We investigate the impact of point spread function (PSF) fitting errors on cosmic shear measurements using the concepts of complexity and sparsity. Complexity, introduced in a previous paper, characterizes the number of degrees of freedom…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 S. Paulin-Henriksson , A. Refregier , A. Amara

Raman spectroscopy, a photonic modality based on the inelastic backscattering of coherent light, is a valuable asset to the intraoperative sensing space, offering non-ionizing potential and highly-specific molecular fingerprint-like…

Image and Video Processing · Electrical Eng. & Systems 2024-01-18 Ashutosh Raman , Ren A. Odion , Kent K. Yamamoto , Weston Ross , Tuan Vo-Dinh , Patrick J. Codd

This paper presents two approaches for filter design based on stochastic distances for intensity speckle reduction. A window is defined around each pixel, overlapping samples are compared and only those which pass a goodness-of-fit test are…

Information Theory · Computer Science 2013-08-21 Leonardo Torres , Alejandro C. Frery

The accuracy in the photometry of a point source depends on the point-spread function (PSF), detector pixelization, and observing strategy. The PSF and pixel response describe the spatial blurring of the source, the pixel scale describes…

Instrumentation and Methods for Astrophysics · Physics 2012-02-02 Johan Samsing , Alex G. Kim

The quantization error in a fixed-size Self-Organizing Map (SOM) with unsupervised winner-take-all learning has previously been used successfully to detect, in minimal computation time, highly meaningful changes across images in medical…

Computer Vision and Pattern Recognition · Computer Science 2020-11-10 John M Wandeto , Birgitta Dresp-Langley

The manifestation of the wave nature of light through diffraction imposes limits on the resolution of optical imaging. For over a century, the Abbe-Rayleigh criterion has been utilized to assess the spatial resolution limits of optical…

Adaptive optics (AO) system performance is improved using post-processing techniques, such as point spread function (PSF) deconvolution. The PSF estimation involves characterization of the different wavefront (WF) error sources in the AO…

Instrumentation and Methods for Astrophysics · Physics 2018-08-29 Florian Ferreira , Eric Gendron , Gérard Rousset , Damien Gratadour

Angular differential imaging is a high-contrast imaging technique that reduces quasi-static speckle noise and facilitates the detection of nearby companions. A sequence of images is acquired with an altitude/azimuth telescope while the…

Astrophysics · Physics 2009-11-13 C. Marois , D. Lafreniere , R. Doyon , B. Macintosh , D. Nadeau

This paper investigates the range ambiguity function of near-field systems where bandwidth and near-field beamfocusing jointly determine the resolution. First, the general matched filter ambiguity function is derived and the near-field…

Signal Processing · Electrical Eng. & Systems 2026-01-21 Marcin Wachowiak , André Bourdoux , Sofie Pollin

We propose a Bayesian image super-resolution (SR) method with a causal Gaussian Markov random field (MRF) prior. SR is a technique to estimate a spatially high-resolution image from given multiple low-resolution images. An MRF model with…

Computer Vision and Pattern Recognition · Computer Science 2015-05-30 Takayuki Katsuki , Akira Torii , Masato Inoue

Camera calibration is an essential process in photogrammetry, serving as a crucial link between the 2D image coordinate system and the 3D world coordinate system. However, when observations are conducted through refractive interfaces, the…

Wide-field survey instruments are used to efficiently observe large regions of the sky. To achieve the necessary field of view, and to provide a higher signal-to-noise ratio for faint sources, many modern instruments are undersampled.…

The matched filter (MF) is one of the most popular and reliable techniques to the detect signals of known structure and amplitude smaller than the level of the contaminating noise. Under the assumption of stationary Gaussian noise, MF…

Instrumentation and Methods for Astrophysics · Physics 2017-08-30 Roberto Vio , Clara Verges , Paola Andreani
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