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Fourier ptychography is a recently explored imaging method for overcoming the diffraction limit of conventional cameras with applications in microscopy and yielding high-resolution images. In order to splice together low-resolution images…

Image and Video Processing · Electrical Eng. & Systems 2020-03-18 Yican Chen , Zhi Luo , Xia Wu , Huidong Yang , Bo Huang

Modern interferometric imaging relies on advanced calibration that incorporates direction-dependent effects. Their increasing number of antennas (e.g. in LOFAR, VLA, MeerKAT/SKA) and sensitivity are often tempered with the accuracy of their…

Instrumentation and Methods for Astrophysics · Physics 2019-03-20 K. Iheanetu , J. N. Girard , O. Smirnov , K. M. B. Asad , M. de Villiers , K. Thorat , S. Makhathini , R. A. Perley

We discuss the technique of Wide-field imaging as it applies to Very Long Baseline Interferometry (VLBI). In the past VLBI data sets were usually averaged so severely that the field-of-view was typically restricted to regions extending a…

Astrophysics · Physics 2009-10-31 M. A. Garrett , R. W. Porcas , A. Pedlar , T. W. B. Muxlow , S. T. Garrington

Integrated optic beam combiners offer many advantages over conventional bulk optic implementations for astronomical imaging. To date, integrated optic beam combiners have only been demonstrated at operating wavelengths below 4 microns.…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 Hsien-kai Hsiao , Kim A. Winick , John D. Monnier

Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances, and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light,…

Instrumentation and Methods for Astrophysics · Physics 2015-04-21 Dainis Dravins , Tiphaine Lagadec , Paul D. Nuñez

We present computer simulations of interferometric imaging with the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory (ESO) and the Astronomical MultiBEam Recombiner (AMBER) phase-closure instrument. These…

Astrophysics · Physics 2015-06-24 F. Przygodda , T. Bloecker , K. -H. Hofmann , G. Weigelt

Linear optical elements are pivotal instruments in the manipulation of classical and quantum states of light. The vast progress in integrated quantum photonic technology enables the implementation of large numbers of such elements on chip…

Quantum Physics · Physics 2016-10-10 Max Tillmann , Christian Schmidt , Philip Walther

Diffusion priors have been used for blind face restoration (BFR) by fine-tuning diffusion models (DMs) on restoration datasets to recover low-quality images. However, the naive application of DMs presents several key limitations. (i) The…

Computer Vision and Pattern Recognition · Computer Science 2025-03-25 Senmao Li , Kai Wang , Joost van de Weijer , Fahad Shahbaz Khan , Chun-Le Guo , Shiqi Yang , Yaxing Wang , Jian Yang , Ming-Ming Cheng

Optical stellar interferometers have demonstrated milli-arcsecond resolution with few apertures spaced hundreds of meters apart. To obtain rich direct images, many apertures will be needed, for a better sampling of the incoming wavefront.…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha , Antoine Labeyrie

Interferometry provides one of the possible routes to ultra-high angular resolution for X-ray and gamma-ray astronomy. Sub-micro-arc-second angular resolution, necessary to achieve objectives such as imaging the regions around the event…

Instrumentation and Methods for Astrophysics · Physics 2009-07-31 G. K. Skinner , J. F. Krizmanic

Chromatic aberration in optical systems arises from the wavelength dependence of a glass's refractive index. Polychromatic rays incident upon an optical surface are refracted at slightly different angles and in traversing an optical system…

Since the 1970s, much of traditional interferometric imaging has been built around variations of the CLEAN algorithm, in both terminology, methodology, and algorithm development. Recent developments in applying new algorithms from convex…

Instrumentation and Methods for Astrophysics · Physics 2020-09-29 Luke Pratley , Melanie Johnston-Hollitt , Jason D. McEwen

Photoelectron holography constitutes a powerful tool for the ultrafast imaging of matter, as it combines high electron currents with subfemtosecond resolution, and gives information about transition amplitudes and phase shifts. Similarly to…

Atomic Physics · Physics 2020-02-19 C. Figueira de Morisson Faria , A. S. Maxwell

Accurate 3D reconstruction of colored objects with structured light (SL) is hindered by lateral chromatic aberration (LCA) in optical components and uneven noise characteristics across RGB channels. This paper introduces lateral chromatic…

Computer Vision and Pattern Recognition · Computer Science 2026-03-12 Wonbeen Oh , Jae-Sang Hyun

An extension may be proposed to the intensity interferometer of Hanbury Brown and Twiss to provide the Fourier phase measurement by the use of third-order intensity correlations. It is well known that interferometric reconstruction of…

Astrophysics · Physics 2008-06-14 B. E. Zhilyaev

Optical coherence tomography (OCT) is a non-invasive, micrometer-scale imaging modality that has become a clinical standard in ophthalmology. By raster-scanning the retina, sequential cross-sectional image slices are acquired to generate…

Image and Video Processing · Electrical Eng. & Systems 2024-02-20 Stefan Ploner , Jungeun Won , Julia Schottenhamml , Jessica Girgis , Kenneth Lam , Nadia Waheed , James Fujimoto , Andreas Maier

Imaging interferometric data in radio astronomy requires the use of non-linear algorithms that rely on different assumptions on the source structure and may produce non-unique results. This is especially true for Very Long Baseline…

Instrumentation and Methods for Astrophysics · Physics 2024-01-19 A. Mus , I. Martí-Vidal

Many important techniques for investigating the properties of extragalactic radio sources, such as spectral-index and rotation-measure mapping, involve the comparison of images at two or more frequencies. In the case of radio…

Astrophysics · Physics 2009-11-13 S. M. Croke , D. C. Gabuzda

Finding a suitable very long baseline (VLBI) interferometer geometry is a key task in planning observations, especially imaging sessions. The main characteristic of the quality of VLBI imaging data is the (u, v)-coverage. In the case when…

Instrumentation and Methods for Astrophysics · Physics 2024-04-01 I. I. Bulygin , M. A. Shchurov , A. G. Rudnitskiy

High-resolution observations by visible and near-infrared interferometers of both single stars and binaries have made significant contributions to the foundations that underpin many aspects of our knowledge of stellar structure and…

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