English
Related papers

Related papers: Coma Off It: Removing Variable Point Spread Functi…

200 papers

The influence of low-spatial frequency errors of an optical component of an imaging system on the point spread function can be quantified using Zernike polynomials. High-spatial frequency errors cause strong scattering due to which the…

Optics · Physics 2026-04-03 Luuk Zonneveld , Paul Urbach , Aurèle Adam

(abridged) We examine the spatial and temporal stability of the HST ACS Wide Field Camera (WFC) point spread function (PSF) using the two square degree COSMOS survey. We show that stochastic aliasing of the PSF necessarily occurs during…

Astronomical instruments generally possess spatially variant point-spread functions, which determine the amount by which an image pixel is blurred as a function of position. Several techniques have been devised to handle this variability in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Adam Rogers , Jason D. Fiege

Localization microscopy is an imaging technique in which the positions of individual nanoscale point emitters (e.g. fluorescent molecules) are determined at high precision from their images. This is the key ingredient in…

Image and Video Processing · Electrical Eng. & Systems 2020-10-01 Elias Nehme , Daniel Freedman , Racheli Gordon , Boris Ferdman , Lucien E. Weiss , Onit Alalouf , Reut Orange , Tomer Michaeli , Yoav Shechtman

We present a detailed analysis of the point spread function (PSF) of JWST NIRCam imaging in eight filters: F070W, F115W, F150W, F200W, F277W, F356W, F444W, and F480M, using publicly available data. Spatial variations in the PSF FWHM…

Astrophysics of Galaxies · Physics 2023-04-28 Ming-Yang Zhuang , Yue Shen

Application of deconvolution algorithms to astronomical images is often limited by variations in PSF structure over the domain of the images. One major difficulty is that Fourier methods can no longer be used for fast convolutions over the…

Astrophysics · Physics 2009-11-07 Tod R. Lauer

In recent years, there has been a proliferation of wide-field sky surveys to search for a variety of transient objects. Using relatively short focal lengths, the optics of these systems produce undersampled stellar images often marred by a…

Astrophysics · Physics 2009-11-13 Fang Yuan , Carl W. Akerlof

Photometric surveys require precise point spread function (PSF) characterization, as it varies across filters and is crucial for accurate photometry and low surface brightness (LSB) studies. However, the small PSF size provided by default…

Optimal error estimation is key to achieve accurate photometry and astrometry. Stellar fluxes and positions in high angular resolution images are typically measured with PSF fitting routines, such as StarFinder. However, the formal…

Instrumentation and Methods for Astrophysics · Physics 2022-08-12 E. Gallego-Cano , R. Schödel , A. T. Gallego-Calvente , A. M. Ghez

Elongation of the point spread function due to atmospheric dispersion becomes a severe problem for high resolution imaging instruments, if an atmospheric dispersion corrector is not present. In this work we report on a novel technique to…

Instrumentation and Methods for Astrophysics · Physics 2022-04-06 J. A. van den Born , W. Jellema , E. Dijkstra

Propagation of an ultrashort pulse of light through strongly scattering media generates an intricate spatio-spectral speckle that can be described by means of the multi-spectral transmission matrix (MSTM). In conjunction with a spatial…

We study the ubiquitous super-resolution problem, in which one aims at localizing positive point sources in an image, blurred by the point spread function of the imaging device. To recover the point sources, we propose to solve a convex…

Information Theory · Computer Science 2020-09-08 Armin Eftekhari , Tamir Bendory , Gongguo Tang

Field distortion is widespread in imaging systems. If it cannot be measured and corrected well, it will affect the accuracy of photogrammetry. To this end, we proposed a general field distortion model based on Fredholm integration, which…

Image and Video Processing · Electrical Eng. & Systems 2022-05-19 Yunqi Sun , Jianfeng Zhou

In this paper, we propose a novel design of image deblurring in the form of one-shot convolution filtering that can directly convolve with naturally blurred images for restoration. The problem of optical blurring is a common disadvantage to…

Image and Video Processing · Electrical Eng. & Systems 2019-07-22 Mahdi S. Hosseini , Konstantinos N. Plataniotis

Discrete delta functions define the limits of attainable spatial resolution for all imaging systems. Here we construct broad, multi-dimensional discrete functions that replicate closely the action of a Dirac delta function under aperiodic…

Image and Video Processing · Electrical Eng. & Systems 2020-09-01 I. D. Svalbe , D. M. Paganin , T. C. Petersen

In positron emission tomography (PET) imaging, statistical iterative reconstruction (IR) techniques appear particularly promising since they can provide accurate system model. The system model matrix which describes the relationship between…

Hyperspectral images enable precise identification of ground objects by capturing their spectral signatures with fine spectral resolution.While high spatial resolution further enhances this capability, increasing spatial resolution through…

Image and Video Processing · Electrical Eng. & Systems 2024-10-25 Ankur Garg , Meenakshi Sarkar , S. Manthira Moorthi , Debajyoti Dhar

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

Blur in X-ray radiographs not only reduces the sharpness of image edges but also reduces the overall contrast. The effective blur in a radiograph is the combined effect of blur from multiple sources such as the detector panel, X-ray source…

Image and Video Processing · Electrical Eng. & Systems 2020-09-08 K. Aditya Mohan , Robert M. Panas , Jefferson A. Cuadra

Astrophysical images issued from different instruments and/or spectral bands often require to be processed together, either for fitting or comparison purposes. However each image is affected by an instrumental response, also known as PSF,…

Instrumentation and Methods for Astrophysics · Physics 2016-12-07 Alexandre Boucaud , Marco Bocchio , Alain Abergel , François Orieux , Hervé Dole , Mohamed Amine Hadj-Youcef
‹ Prev 1 8 9 10 Next ›