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The reconstruction of images from a small number of projections using the maximum-entropy method (MEM) with the Shannon entropy is considered. MEM provides higher-quality image reconstruction for sources with extended components than the…

Astrophysics · Physics 2008-11-26 Anisa T. Bajkova

In very long baseline interferometry (VLBI) the combination of multiple antennas permits the synthesis of a virtual telescope with a larger diameter and consequently higher resolution than the individual antennae. Yet, due to the sparse…

Instrumentation and Methods for Astrophysics · Physics 2024-08-14 Alejandro Mus , Hendrik Müller , Andrei Lobanov

We consider the problem of fusing an arbitrary number of multiband, i.e., panchromatic, multispectral, or hyperspectral, images belonging to the same scene. We use the well-known forward observation and linear mixture models with Gaussian…

Computer Vision and Pattern Recognition · Computer Science 2018-07-19 Reza Arablouei

We present a numerical method for the reconstruction and optimization of complex field synthesis using coherent pulse combination systems. A genetic algorithm utilizing a Fourier optics based propagation method is developed for accurate…

Optics · Physics 2020-05-29 Randy Lemons , Sergio Carbajo

This paper presents an innovative set of tools to support a methodology for the multichannel interpolation (MCI) of a discrete signal. It is shown that a bandlimited signal $f$ can be exactly reconstructed from finite samples of $g_k$…

Information Theory · Computer Science 2019-04-12 Dong Cheng , Kit Ian Kou

The problem of phaseless aperture synthesis is of current interest in phase-unstable VLBI with a small number of elements when either the use of closure phases is not possible (a two-element interferometer) or their quality and number are…

Astrophysics · Physics 2009-11-10 Anisa T. Bajkova

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

We present RESOLVE, a new algorithm for radio aperture synthesis imaging of extended and diffuse emission in total intensity. The algorithm is derived using Bayesian statistical inference techniques, estimating the surface brightness in the…

Instrumentation and Methods for Astrophysics · Physics 2016-02-03 H. Junklewitz , M. R. Bell , M. Selig , T. A. Enßlin

We describe a "spatio-spectral" deconvolution algorithm for wide-band imaging in radio interferometry. In contrast with the existing multi-frequency reconstruction algorithms, the proposed method does not rely on a model of the…

Instrumentation and Methods for Astrophysics · Physics 2016-03-01 André Ferrari , Jérémy Deguignet , Chiara Ferrari , David Mary , Antony Schutz , Oleg Smirnov

We propose a method for automatic local time-adaptation of the spectrogram of audio signals: it is based on the decomposition of a signal within a Gabor multi-frame through the STFT operator. The sparsity of the analysis in every individual…

Sound · Computer Science 2011-09-29 M. Liuni , A. Röbel , M. Romito , X. Rodet

Recent years have seen the rise of convolutional neural network techniques in exemplar-based image synthesis. These methods often rely on the minimization of some variational formulation on the image space for which the minimizers are…

Statistics Theory · Mathematics 2019-12-05 Valentin De Bortoli , Agnes Desolneux , Alain Durmus , Bruno Galerne , Arthur Leclaire

We discuss a technique for mapping the synchrotron turnover frequency distribution using nearly simultaneous, multi--frequency VLBI observations. The limitations of the technique arising from limited spatial sampling and frequency coverage…

Astrophysics · Physics 2009-10-30 A. P. Lobanov

Because optical systems have huge bandwidth and are capable of generating low noise short pulses they are ideal for undersampling multi-band signals that are located within a very broad frequency range. In this paper we propose a new scheme…

Optics · Physics 2009-11-13 Amir Rosenthal , Alex Linden , Moshe Horowitz

Generating multi-contrasts/modal MRI of the same anatomy enriches diagnostic information but is limited in practice due to excessive data acquisition time. In this paper, we propose a novel deep-learning model for joint reconstruction and…

Image and Video Processing · Electrical Eng. & Systems 2022-06-30 Wanyu Bian , Qingchao Zhang , Xiaojing Ye , Yunmei Chen

We introduce a generalized version of phase retrieval called multiplexed phase retrieval. We want to recover the phase of amplitude-only measurements from linear combinations of them. This corresponds to the case in which multiple…

Image and Video Processing · Electrical Eng. & Systems 2019-07-02 Jonathan Dong , Florent Krzakala , Sylvain Gigan

Assessing the quality of aperture synthesis maps is relevant for benchmarking image reconstruction algorithms, for the scientific exploitation of data from optical long-baseline interferometers, and for the design/upgrade of new/existing…

Instrumentation and Methods for Astrophysics · Physics 2017-02-22 Nuno Gomes , Paulo J. V. Garcia , Éric Thiébaut

With the development of numbers of high resolution data acquisition systems and the global requirement to lower the energy consumption, the development of efficient sensing techniques becomes critical. Recently, Compressed Sampling (CS)…

Information Theory · Computer Science 2015-06-11 Mohammad Golbabaee , Simon Arberet , Pierre Vandergheynst

Hyperspectral imaging systems based on multiple-beam interference (MBI), such as Fabry-Perot interferometry, are attracting interest due to their compact design, high throughput, and fine resolution. Unlike dispersive devices, which measure…

Signal Processing · Electrical Eng. & Systems 2024-10-30 Mohamad Jouni , Daniele Picone , Mauro Dalla Mura

Multiheterodyne techniques using frequency combs -- light sources whose lines are perfectly evenly-spaced -- have revolutionized optical science. By beating an unknown signal with the many lines of a comb, its spectrum is recovered.…

Optics · Physics 2020-04-23 David Burghoff

The multichannel trigonometric reconstruction from uniform samples was proposed recently. It not only makes use of multichannel information about the signal but is also capable to generate various kinds of interpolation formulas according…

Classical Analysis and ODEs · Mathematics 2024-12-20 Dong Cheng , Kit Ian Kou