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We investigate methods to calibrate the non-common path aberrations at an adaptive optics system having a wavefront-correcting device working at an extremely high resolution (larger than 150x150). We use focal-plane images collected…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Visa Korkiakoski , Christoph U. Keller , Niek Doelman , Matthew Kenworthy , Gilles Otten , Michel Verhaegen

Super-resolution (SR) refers to a combination of optical design and signal processing techniques jointly employed to obtain reconstructed wave-fronts at a higher-resolution from multiple low-resolution samples, overcoming the intrinsic…

Instrumentation and Methods for Astrophysics · Physics 2025-12-22 Carlos M. Correia , Charlotte Z. Bond , João Aveiro , François Leroux , Cédric Taïssir Heritier , Christophe Vérinaud

Image restoration aims to restore high-quality images from degraded counterparts and has seen significant advancements through deep learning techniques. The technique has been widely applied to mobile devices for tasks such as mobile…

Computer Vision and Pattern Recognition · Computer Science 2023-08-25 Xiangyu Chen , Ruiwen Zhen , Shuai Li , Xiaotian Li , Guanghui Wang

In a directional modulation network, a general power iterative (GPI) based beamforming scheme is proposed to maximize the secrecy rate (SR), where there are two optimization variables required to be optimized. The first one is the useful…

Information Theory · Computer Science 2018-01-30 Hai Yu , Simin Wan , Wenlong Cai , Ling Xu , Xiaobo Zhou , Jin Wang , Yongpeng Wu , Feng Shu , Jiangzhou Wang , Jianxin Wang

We present UMI (Unified Median Iterative), a novel robust location estimator for detrending photometric time series in exoplanet transit surveys. UMI modifies the standard Tukey bisquare M-estimator with two innovations: (1) an asymmetric…

Instrumentation and Methods for Astrophysics · Physics 2026-04-14 Omar Khan

We use telemetry data from the Gemini North ALTAIR adaptive optics system to investigate how well the commands for wavefront correction (both Tip/Tilt and high-order turbulence) can be forecasted in order to reduce lag error (due to…

Instrumentation and Methods for Astrophysics · Physics 2022-05-16 Rehan Hafeez , Finn Archinuk , Sébastien Fabbro , Hossen Teimoorinia , Jean-Pierre Véran

A new fitting method is explored for momentum reconstruction of tracks in a constant magnetic field for a silicon-strip tracker. Substantial increases of momentum resolution respect to standard fit is obtained. The key point is the use of a…

Instrumentation and Detectors · Physics 2018-12-11 Gregorio Landi , Giovanni E. Landi

Accelerating magnetic resonance image (MRI) reconstruction process is a challenging ill-posed inverse problem due to the excessive under-sampling operation in k-space. In this paper, we propose a recurrent transformer model, namely…

Image and Video Processing · Electrical Eng. & Systems 2022-01-31 Pengfei Guo , Yiqun Mei , Jinyuan Zhou , Shanshan Jiang , Vishal M. Patel

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

We present improvements to the wavelength calibration for the lenslet-based Integral Field Spectrograph (IFS), that serves as the science instrument for the Gemini Planet Imager (GPI). The GPI IFS features a 2.7" $\times$ 2.7" field of view…

Instrumentation and Methods for Astrophysics · Physics 2016-12-14 Schuyler G. Wolff , Kimberly Ward-Duong , Joe Zalesky , Alex Z. Greenbaum , Marshall D. Perrin , James Graham

We consider the problem of reconstructing signals and images from periodic nonlinearities. For such problems, we design a measurement scheme that supports efficient reconstruction; moreover, our method can be adapted to extend to…

Machine Learning · Statistics 2017-10-03 Viraj Shah , Mohammadreza Soltani , Chinmay Hegde

Wavefront sensors encode phase information of an incoming wavefront into an intensity pattern that can be measured on a camera. Several kinds of wavefront sensors (WFS) are used in astronomical adaptive optics. Amongst them, Fourier-based…

Recovering the shape and appearance of real-world objects from natural 2D images is a long-standing and challenging inverse rendering problem. In this paper, we introduce a novel hybrid differentiable rendering method to efficiently…

Computer Vision and Pattern Recognition · Computer Science 2023-08-22 Xiangyang Zhu , Yiling Pan , Bailin Deng , Bin Wang

Magnetic resonance imaging (MRI) is known to have reduced signal-to-noise ratios (SNR) at lower field strengths, leading to signal degradation when producing a low-field MRI image from a high-field one. Therefore, reconstructing a…

Image and Video Processing · Electrical Eng. & Systems 2023-05-05 Zhuo-Xu Cui , Congcong Liu , Chentao Cao , Yuanyuan Liu , Jing Cheng , Qingyong Zhu , Yanjie Zhu , Haifeng Wang , Dong Liang

Inferring interior properties of the Sun from photospheric measurements of the seismic wavefield constitutes the helioseismic inverse problem. Deviations in seismic measurements (such as wave travel times) from their fiducial values…

Solar and Stellar Astrophysics · Physics 2015-06-18 Shravan Hanasoge , Jeroen Tromp

AI-based neural decoding reconstructs visual perception by leveraging generative models to map brain activity, measured through functional MRI (fMRI), into latent hierarchical representations. Traditionally, ridge linear models transform…

Image and Video Processing · Electrical Eng. & Systems 2025-09-04 Lorenzo Veronese , Andrea Moglia , Luca Mainardi , Pietro Cerveri

We present an algorithm for reconstructing the radiance field of a large-scale scene from a single casually captured video. The task poses two core challenges. First, most existing radiance field reconstruction approaches rely on accurate…

Computer Vision and Pattern Recognition · Computer Science 2023-03-27 Andreas Meuleman , Yu-Lun Liu , Chen Gao , Jia-Bin Huang , Changil Kim , Min H. Kim , Johannes Kopf

Phase retrieval, a nonlinear problem prevalent in imaging applications, has been extensively studied using random models, some of which with i.i.d. sensing matrix components. While these models offer robust reconstruction guarantees, they…

Optics · Physics 2024-09-10 Zhiyuan Hu , Julián Tachella , Michael Unser , Jonathan Dong

Fourier ptychographic microscopy (FPM) is a pivotal computational imaging technique that achieves phase and amplitude reconstruction with high resolution and wide field of view, using low numerical aperture objectives and LED array…

With its high sensitivity, the Pyramid wavefront sensor (PyWFS) is becoming an advantageous sensor for astronomical adaptive optics (AO) systems. However, this sensor exhibits significant non-linear behaviours leading to challenging AO…

Instrumentation and Methods for Astrophysics · Physics 2021-05-12 Vincent Chambouleyron , Olivier Fauvarque , Jean-François Sauvage , Benoît Neichel , Thierry Fusco