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Laser speckle, the granular intensity pattern arising from random optical interference, provides a high-dimensional encoding of spectral information that can be exploited for precision metrology. Speckle-based spectrometers have advanced…

We introduce the first end-to-end learning-based solution to near-field Photometric Stereo (PS), where the light sources are close to the object of interest. This setup is especially useful for reconstructing large immobile objects. Our…

Computer Vision and Pattern Recognition · Computer Science 2022-03-31 Daniel Lichy , Soumyadip Sengupta , David W. Jacobs

Coherent X-ray photons with energies higher than 50 keV offer new possibilities for imaging nanoscale lattice distortions in bulk crystalline materials using Bragg peak phase retrieval methods. However, the compression of reciprocal space…

Signal Processing · Electrical Eng. & Systems 2018-08-14 Siddharth Maddali , Irene Calvo-Almazan , Jonathan Almer , Peter Kenesei , Jun-Sang Park , Ross Harder , Youssef Nashed , Stephan Hruszkewycz

The effects of photon noise, aliasing, wavefront chromaticity and scintillation on the point spread function (PSF) contrast achievable with ground based adaptive optics (AO) are evaluated for different wavefront sensing schemes. I show that…

Astrophysics · Physics 2009-11-11 Olivier Guyon

The development of X-ray Free Electron Lasers (XFELs) has opened numerous opportunities to probe atomic structure and ultrafast dynamics of various materials. Single Particle Imaging (SPI) with XFELs enables the investigation of biological…

Computer Vision and Pattern Recognition · Computer Science 2023-11-29 Zhantao Chen , Cong Wang , Mingye Gao , Chun Hong Yoon , Jana B. Thayer , Joshua J. Turner

We propose a new post-processing technique for the detection of faint companions from a sequence of adaptive optics corrected short exposures. The algorithm exploits the difference in shape between the on-axis and off-axis irradiance…

Astrophysics · Physics 2009-11-13 Szymon Gladysz , Julian C. Christou

Using light spectra is an essential element in many applications, for example, in material classification. Often this information is acquired by using a hyperspectral camera. Unfortunately, these cameras have some major disadvantages like…

Image and Video Processing · Electrical Eng. & Systems 2022-09-19 Frank Sippel , Jürgen Seiler , André Kaup

Fluorescence imaging is an essential diagnostic tool in many fields, but diffraction-limited optical imaging at depth is limited by scattering. Here, we present a method based on multiple random illuminations, combined with a computational…

Optics · Physics 2026-03-30 Lei Zhu , Tengfei Wu , Bernhard Rauer , Hilton B. de Aguiar , Sylvain Gigan

Adaptive stretching, where the post compression signal is iteratively stretched to maximize the correlation between the pre and post compression rf echo frames, has demonstrated superior performance compared to gradient based methods. At…

Tissues and Organs · Quantitative Biology 2022-10-25 Shaiban Ahmed , Rasheed Abid , S. Kaisar Alam

Astrometric precision and knowledge of the point spread function are key ingredients for a wide range of astrophysical studies including time-delay cosmography in which strongly lensed quasar systems are used to determine the Hubble…

Instrumentation and Methods for Astrophysics · Physics 2021-09-22 Geoff C. -F. Chen , Tommaso Treu , Christopher D. Fassnacht , Sam Ragland , Thomas Schmidt , Sherry H. Suyu

We introduce a new algorithm for interpolating measurements of the point-spread function (PSF) using stars from many exposures. The principal components of the variation in the PSF pattern from multiple exposures are used to solve for…

Astrophysics · Physics 2007-05-23 Mike Jarvis , Bhuvnesh Jain

Optical interferometers provide multiple wavelength measurements. In order to fully exploit the spectral and spatial resolution of these instruments, new algorithms for image reconstruction have to be developed. Early attempts to deal with…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Éric Thiébaut , Ferréol Soulez , Loïc Denis

High-contrast imaging (HCI) is one of the most challenging techniques for exoplanet detection. It relies on sophisticated data processing to reach high contrasts at small angular separations. Most data processing techniques of this type are…

Instrumentation and Methods for Astrophysics · Physics 2021-02-10 Carl-Henrik Dahlqvist , Olivier Absil

In many image processing tasks it occurs that pixels or blocks of pixels are missing or lost in only some channels. For example during defective transmissions of RGB images, it may happen that one or more blocks in one color channel are…

Image and Video Processing · Electrical Eng. & Systems 2022-09-19 Frank Sippel , Jürgen Seiler , André Kaup

High resolution images can be acquired using a non-regular sampling sensor which consists of an underlying low resolution sensor that is covered with a non-regular sampling mask. The reconstructed high resolution image is then obtained…

Image and Video Processing · Electrical Eng. & Systems 2022-04-08 Markus Jonscher , Karina Jaskolka , Jürgen Seiler , André Kaup

Direct exoplanet detection is limited by speckle noise in the point spread function (PSF) of the central star. This noise can be reduced by subtracting PSF images obtained simultaneously in adjacent narrow spectral bands using a…

A novel method to estimate the pixels simultaneous detection probability and the spatial resolution of pixelized detectors is proposed, which is based on the determination of the statistical correlations between detector neighbor pixels.…

Medical Physics · Physics 2008-02-25 V. Grabski

New lensless diffractive X-ray technic for micro-scale imaging of biological tissue is based on quantitative phase retrieval schemes. By incorporating refraction, this method yields improved contrast compared to purely absorption-based…

Numerical Analysis · Mathematics 2018-03-28 Victor Palamodov

Point-spread function of the probe forming optics ($PSF_{optics} $) is reported for the first time in an uncorrected (without multipole correctors) scanning electron microscope (SEM). In an SEM, the electron probe information is lost as the…

Materials Science · Physics 2024-07-02 Surya Kamal , Richard K. Hailstone

The contrasts of features in the quiet Sun are studied using filtergrams recorded by the Broad-band Filter Imager on the Hinode/Solar Optical Telescope. In a first step, the scattered light originating in the instrument is modeled using…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. K. Mathew , V. Zakharov , S. K. Solanki
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