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Astronomers usually need the highest angular resolution possible, but the blurring effect of diffraction imposes a fundamental limit on the image quality from any single telescope. Interferometry allows light collected at widely-separated…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 John D. Monnier , Ronald J. Allen

Real-world imaging systems acquire measurements that are degraded by noise, optical aberrations, and other imperfections that make image processing for human viewing and higher-level perception tasks challenging. Conventional cameras…

Computer Vision and Pattern Recognition · Computer Science 2021-05-11 Steven Diamond , Vincent Sitzmann , Frank Julca-Aguilar , Stephen Boyd , Gordon Wetzstein , Felix Heide

In this paper, we explore a principal way to enhance the quality of object masks produced by different segmentation models. We propose a model-agnostic solution called SegRefiner, which offers a novel perspective on this problem by…

Computer Vision and Pattern Recognition · Computer Science 2023-12-20 Mengyu Wang , Henghui Ding , Jun Hao Liew , Jiajun Liu , Yao Zhao , Yunchao Wei

High-resolution x-ray microscopy requires a high photon flux to measure the signal from weakly scattering samples. This exposes samples to high radiation doses, potentially damaging or destroying them through radiation damage. In this work,…

Medical Physics · Physics 2024-09-04 Felix Wittwer , Peter Modregger

An azimuthally electric-polarized vector beam (APB), with a polarization vortex, has a salient feature that it contains a magnetic-dominant region within which electric field ideally has a null while longitudinal magnetic field is maximum.…

Optics · Physics 2016-11-03 Mehdi Veysi , Caner Guclu , Filippo Capolino

We present a new method to achieve high-contrast images using segmented and/or on-axis telescopes. Our approach relies on using two sequential Deformable Mirrors to compensate for the large amplitude excursions in the telescope aperture due…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Laurent Pueyo , Colin Norman

Exoplanet direct imaging using adaptive optics (AO) is often limited by non-common path aberrations (NCPAs) and aberrations that are invisible to traditional pupil-plane wavefront sensors (WFSs). This can be remedied by focal-plane (FP)…

Steganalysis as a method to detect whether image contains se-cret message, is a crucial study avoiding the imperils from abus-ing steganography. The point of steganalysis is to detect the weak embedding signals which is hardly learned by…

Multimedia · Computer Science 2022-03-25 Hai Su , Meiyin Han , Junle Liang , Songsen Yu

We present a novel method for local image feature matching. Instead of performing image feature detection, description, and matching sequentially, we propose to first establish pixel-wise dense matches at a coarse level and later refine the…

Computer Vision and Pattern Recognition · Computer Science 2021-04-02 Jiaming Sun , Zehong Shen , Yuang Wang , Hujun Bao , Xiaowei Zhou

Filters are key devices in optical systems and are usually applied to signal suppression or selection based on their amplitude frequency responses. Different from amplitude filtering, an all-pass filter (APF) is a unique type of filter that…

Optics · Physics 2019-05-27 Lu Xu , Yuan Yu , Xiaolong Liu , Xuewen Shu , Xinliang Zhang

Phase-Stretch Adaptive Gradient-Field Extractor (PAGE) is an edge detection algorithm that is inspired by physics of electromagnetic diffraction and dispersion. A computational imaging algorithm, it identifies edges, their orientations and…

Image and Video Processing · Electrical Eng. & Systems 2022-02-15 Callen MacPhee , Madhuri Suthar , Bahram Jalali

One of the most prominent challenges in the field of diffractive imaging is the phase retrieval (PR) problem: In order to reconstruct an object from its diffraction pattern, the inverse Fourier transform must be computed. This is only…

Image and Video Processing · Electrical Eng. & Systems 2022-05-06 Simon Welker , Tal Peer , Henry N. Chapman , Timo Gerkmann

Synthesizing a densely sampled light field from a single image is highly beneficial for many applications. Moreover, jointly solving both angular and spatial super-resolution problem also introduces new possibilities in light field imaging.…

Image and Video Processing · Electrical Eng. & Systems 2020-06-30 Andre Ivan , Williem , In Kyu Park

Most deraining works focus on rain streaks removal but they cannot deal adequately with heavy rain images. In heavy rain, streaks are strongly visible, dense rain accumulation or rain veiling effect significantly washes out the image,…

Computer Vision and Pattern Recognition · Computer Science 2019-04-11 Ruotent Li , Loong Fah Cheong , Robby T. Tan

Optical contrast is the most common preliminary method to identify layer number of two-dimensional (2D) materials, but is seldom used as a confirmatory technique. We explain the reason for variation of optical contrast between imaging…

Optics · Physics 2022-09-12 Mainak Mondal , Ajit Kumar Dash , Akshay Singh

Particle Filter is an effective solution to track objects in video sequences in complex situations. Its key idea is to estimate the density over the possible states of the object using a weighted sample whose elements are called particles.…

Computer Vision and Pattern Recognition · Computer Science 2012-10-19 Severine Dubuisson , Christophe Gonzales , Xuan Son NGuyen

Far Infrared interferometry is the main diagnostics method for electron density measurements in medium sized tokamaks. The transverse density gradients of plasma produce refractive effect, and the probing radiation does not propagate along…

Plasma Physics · Physics 2025-01-31 Rajwinder Kaur , Asha Adhiya

A Light Field (LF) camera consists of an additional two-dimensional array of micro-lenses placed between the main lens and sensor, compared to a conventional camera. The sensor pixels under each micro-lens receive light from a sub-aperture…

Computer Vision and Pattern Recognition · Computer Science 2025-11-11 Suresh Nehra , Aupendu Kar , Jayanta Mukhopadhyay , Prabir Kumar Biswas

The growing burden of myopia and retinal diseases necessitates more accessible and efficient eye screening solutions. This study presents a compact, dual-function optical device that integrates fundus photography and refractive error…

Image and Video Processing · Electrical Eng. & Systems 2025-04-29 Boyuan Peng , Jiaju Chen , Yiwei Zhang , Cuiyi Peng , Junyang Li , Jiaming Deng , Peiwu Qin

Infrared (IR) blocking filters are crucial for controlling the radiative loading on cryogenic systems and for optimizing the sensitivity of bolometric detectors in the far-IR. We present a new IR filter approach based on a combination of…

Instrumentation and Methods for Astrophysics · Physics 2018-05-23 C. D. Munson , S. K. Choi , K. P. Coughlin , J. J. McMahon , K. H. Miller , L. A. Page , E. J. Wollack