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We describe and experimentally validate an algorithm to reconstruct an unknown extended object from through-focus measured image intensities blurred by unknown aberrations. It is shown that the method can recover diffraction-limited image…

Optics · Physics 2015-10-29 Yifeng Shao , Niek Doelman , Silvania F. Pereira , H. Paul Urbach

Ankylography is a new 3D imaging technique, which, under certain circumstances, enables reconstruction of a 3D object from a single sample orientation. Here, we provide a matrix rank analysis to explain the principle of ankylography. We…

We present a new processing technique aimed at significantly improving the angular differential imaging method (ADI) in the context of high-contrast imaging of faint objects nearby bright stars in observations obtained with extreme adaptive…

Instrumentation and Methods for Astrophysics · Physics 2017-11-15 Gianluca Li Causi , Marco Stangalini , Simone Antoniucci , Fernando Pedichini , Massimiliano Mattioli , Vincenzo Testa

Accurately measuring the geometry and spatially-varying reflectance of real-world objects is a complex task due to their intricate shapes formed by concave features, hollow engravings and diverse surfaces, resulting in inter-reflection and…

Computer Vision and Pattern Recognition · Computer Science 2024-12-16 Jing Yang , Pratusha Bhuvana Prasad , Qing Zhang , Yajie Zhao

Recently introduced angular-memory-effect based techniques enable non-invasive imaging of objects hidden behind thin scattering layers. However, both the speckle-correlation and the bispectrum analysis are based on the statistical average…

Optics · Physics 2017-11-22 Tengfei Wu , Jonathan Dong , Xiaopeng Shao , Sylvain Gigan

The major cornerstone of future ground-based astronomy is imaging and spectroscopy at the diffraction limit using adaptive optics. To exploit the potential of current AO systems, we have begun a survey around bright stars to study…

Astrophysics · Physics 2007-05-23 R. I. Davies , M. Lehnert , A. J. Baker , S. Rabien

The far-field resolution of optical imaging systems is restricted by the Abbe diffraction limit, a direct result of the wave nature of light. One successful technological approach to circumventing this limit is to reduce the effective size…

Accurate and fast 3D imaging of specular surfaces still poses major challenges for state-of-the-art optical measurement principles. Frequently used methods, such as phase-measuring deflectometry (PMD) or shape-from-polarization (SfP), rely…

Computer Vision and Pattern Recognition · Computer Science 2024-06-05 Jiazhang Wang , Oliver Cossairt , Florian Willomitzer

Existing oriented object detection methods commonly use metric AP$_{50}$ to measure the performance of the model. We argue that AP$_{50}$ is inherently unsuitable for oriented object detection due to its large tolerance in angle deviation.…

Computer Vision and Pattern Recognition · Computer Science 2024-04-09 Ying Zeng , Yushi Chen , Xue Yang , Qingyun Li , Junchi Yan

Scanning transmission electron microscopy (STEM) has been extensively used for imaging complex materials down to atomic resolution. The most commonly employed STEM modality, annular dark-field imaging, produces easily-interpretable…

Optical diffraction tomography measures the three-dimensional refractive index map of a specimen and visualizes biochemical phenomena at the nanoscale in a non-destructive manner. One major drawback of optical diffraction tomography is poor…

Image and Video Processing · Electrical Eng. & Systems 2020-09-30 DongHun Ryu , Dongmin Ryu , YoonSeok Baek , Hyungjoo Cho , Geon Kim , Young Seo Kim , Yongki Lee , Yoosik Kim , Jong Chul Ye , Hyun-Seok Min , YongKeun Park

Deepfake detection refers to detecting artificially generated or edited faces in images or videos, which plays an essential role in visual information security. Despite promising progress in recent years, Deepfake detection remains a…

Computer Vision and Pattern Recognition · Computer Science 2023-12-11 Chunlei Peng , Huiqing Guo , Decheng Liu , Nannan Wang , Ruimin Hu , Xinbo Gao

In this paper, we propose a new model to segment cells in phase contrast microscopy images. Cell images collected from the similar scenario share a similar background. Inspired by this, we separate cells from the background in images by…

Computer Vision and Pattern Recognition · Computer Science 2019-04-02 Lin Zhang

Numerous vector angular spectrum methods have been presented to model the vectorial nature of diffractive electromagnetic field, facilitating optical field engineering in polarization-related and high numerical aperture systems. However,…

Optics · Physics 2025-09-29 Chengda Song , Jing He , Guanghui Yuan

In Fluorescein Angiography (FA), an exogenous dye is injected in the bloodstream to image the vascular structure of the retina. The injected dye can cause adverse reactions such as nausea, vomiting, anaphylactic shock, and even death. In…

Image and Video Processing · Electrical Eng. & Systems 2022-05-02 Sharif Amit Kamran , Khondker Fariha Hossain , Alireza Tavakkoli , Stewart Lee Zuckerbrod , Salah A. Baker

We propose an interferometry experiment for the detection of axion-like particles (ALPs). As in ordinary photon-regeneration (light shining through a wall) experiments, a laser beam traverses a region permeated by a magnetic field, where…

High Energy Physics - Phenomenology · Physics 2018-08-28 H. Tam , Q. Yang

Camera arrays provide spatial and angular information within a single snapshot. With refocusing methods, focal planes can be altered after exposure. In this letter, we propose a light field refocusing method to improve the imaging quality…

Image and Video Processing · Electrical Eng. & Systems 2021-08-29 Yingqian Wang , Jungang Yang , Yulan Guo , Chao Xiao , Wei An

We consider the inverse problem of in-line holography, applied to minimally-destructive imaging of cold atom clouds. Absorption imaging near-resonance provides a simple, but destructive measurement of atom column density. Imaging off…

Atomic Physics · Physics 2009-11-11 L. D. Turner , K. F. E. M. Domen , R. E. Scholten

Digital holography numerically restores three-dimensional image information using optically captured diffractive waves. The required bandwidth is larger than that of hologram pixel at a closer distance in the Fresnel diffraction regime,…

Optics · Physics 2024-01-12 Byung Gyu Chae

We conceptualise and numerically simulate a resonant metamaterial interface incorporating non-local, or beyond nearest neighbour, coupling that acts as a discrete angular filter. It can be designed to yield perfect transmission at…

Applied Physics · Physics 2024-10-24 Tristan. M. Lawrie , Gregor. Tanner , Gregory. J. Chaplain