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Signal recovery from nonlinear measurements involves solving an iterative optimization problem. In this paper, we present a framework to optimize the sensing parameters to improve the quality of the signal recovered by the given iterative…

Image and Video Processing · Electrical Eng. & Systems 2020-06-09 Zikui Cai , Rakib Hyder , M. Salman Asif

Reconstruction of the point spread function (PSF) plays an important role in many areas of astronomy, including photometry, astrometry, galaxy morphology, and shear measurement. The atmospheric and instrumental effects are the two main…

Instrumentation and Methods for Astrophysics · Physics 2024-04-25 Pedro Alonso , Jun Zhang , Cong Liu

Three-dimensional phase contrast imaging of multiply-scattering samples in X-ray and electron microscopy is extremely challenging, due to small numerical apertures, the unavailability of wavefront shaping optics, and the highly nonlinear…

Computational Physics · Physics 2021-06-02 Philipp M Pelz , Hamish G Brown , Jim Ciston , Scott D Findlay , Yaqian Zhang , Mary Scott , Colin Ophus

Quantitative differential phase contrast imaging of materials in atomic-resolution scanning transmission electron microscopy using segmented detectors is limited by various factors, including coherent and incoherent aberrations, detector…

An algorithm for determining crystal structures from diffraction data is described which does not rely on the usual Fourier-space formulations of atomicity. The new algorithm implements atomicity constraints in real-space, as well as…

Condensed Matter · Physics 2007-05-23 Veit Elser

The mutual intensity and its equivalent phase-space representations quantify an optical field's state of coherence and are important tools in the study of light propagation and dynamics, but they can only be estimated indirectly from…

Optics · Physics 2017-11-16 Chenglong Bao , George Barbastathis , Hui Ji , Zuowei Shen , Zhengyun Zhang

Based on phase retrieval, lensless coherent imaging and in particular holography offers quantitative phase and amplitude images. This is of particular importance for spectral ranges where suitable lenses are challenging, such as for hard…

Image and Video Processing · Electrical Eng. & Systems 2022-09-01 Simon Huhn , Leon Merten Lohse , Jens Lucht , Tim Salditt

Diffusion-based image compression methods have achieved notable progress, delivering high perceptual quality at low bitrates. However, their practical deployment is hindered by significant inference latency and heavy computational overhead,…

Computer Vision and Pattern Recognition · Computer Science 2026-02-03 Yiwen Jia , Hao Wei , Yanhui Zhou , Chenyang Ge

Recently introduced speckle-correlations based techniques enable noninvasive imaging of objects hidden behind scattering layers. In these techniques the hidden object Fourier amplitude is retrieved from the scattered light autocorrelation,…

Optics · Physics 2022-01-19 Tengfei Wu , Ori Katz , Xiaopeng Shao , Sylvain Gigan

Compression of the sign information of discrete cosine transform coefficients is an intractable problem in image compression schemes due to the equiprobable occurrence of the sign bits. To overcome this difficulty, we propose an efficient…

Information Theory · Computer Science 2024-05-22 Chihiro Tsutake , Keita Takahashi , Toshiaki Fujii

Iterative methods for tomographic image reconstruction have great potential for enabling high quality imaging from low-dose projection data. The computational burden of iterative reconstruction algorithms, however, has been an impediment in…

Image and Video Processing · Electrical Eng. & Systems 2019-07-25 Kai Zhang , Alireza Entezari

In this work, we propose using camera arrays coupled with coherent illumination as an effective method of improving spatial resolution in long distance images by a factor of ten and beyond. Recent advances in ptychography have demonstrated…

Computer Vision and Pattern Recognition · Computer Science 2015-11-29 Jason Holloway , M. Salman Asif , Manoj Kumar Sharma , Nathan Matsuda , Roarke Horstmeyer , Oliver Cossairt , Ashok Veeraraghavan

Conventional optical coherent receivers capture the full electrical field, including amplitude and phase, of a signal waveform by measuring its interference against a stable continuous-wave local oscillator (LO). In optical coherent…

Signal Processing · Electrical Eng. & Systems 2020-06-24 Haoshuo Chen , Nicolas K. Fontaine , Joan M. Gene , Roland Ryf , David T. Neilson , Gregory Raybon

This paper presents a novel approach on solving the phase problem in nuclear magnetic resonance (NMR) diffusion pore imaging, a method, which allows imaging the shape of arbitrary closed pores filled with an NMR-detectable medium for…

We investigate the utility of meta-optical encoders for generalizable image compression by leveraging their intrinsic shift-invariant point spread functions (PSFs). Compared with purely digital approaches, such optical encoders offer…

Optics · Physics 2026-02-23 Yubo Zhang , Rui Chen , Zhihao Zhou , Arka Majumdar

Diffusion models have demonstrated their utility as learned priors for solving various inverse problems. However, most existing approaches are limited to linear inverse problems. This paper exploits the efficient and unsupervised posterior…

Image and Video Processing · Electrical Eng. & Systems 2025-01-07 Mehmet Onurcan Kaya , Figen S. Oktem

Modern high-resolution satellite sensors collect optical imagery with ground sampling distances (GSDs) of 30-50cm, which has sparked a renewed interest in photogrammetric 3D surface reconstruction from satellite data. State-of-the-art…

Computer Vision and Pattern Recognition · Computer Science 2020-05-14 Mathias Rothermel , Ke Gong , Dieter Fritsch , Konrad Schindler , Norbert Haala

We consider the reconstruction of a two-dimensional discrete image from a set of tomographic measurements corresponding to the Radon projection. Assuming that the image has a structure where neighbouring pixels have a larger probability to…

Numerical Analysis · Computer Science 2013-04-04 Emmanuelle Gouillart , Florent Krzakala , Marc Mezard , Lenka Zdeborová

We propose a compact snapshot monocular depth estimation technique that relies on an engineered point spread function (PSF). Traditional approaches used in microscopic super-resolution imaging such as the Double-Helix PSF (DHPSF) are…

Image and Video Processing · Electrical Eng. & Systems 2022-08-05 Bhargav Ghanekar , Vishwanath Saragadam , Dushyant Mehra , Anna-Karin Gustavsson , Aswin Sankaranarayanan , Ashok Veeraraghavan

Phase retrieval problems in antenna measurements arise when a reference phase cannot be provided to all measurement locations. Phase retrieval algorithms require sufficiently many independent measurement samples of the radiated fields to be…

Signal Processing · Electrical Eng. & Systems 2022-06-24 Josef Knapp , Alexander Paulus , Jonas Kornprobst , Uwe Siart , Thomas F. Eibert
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