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X-ray fluorescence holography (XFH) is a method for obtaining diffraction-limited images of the local atomic structure around a given type of emitter. The reconstructed wave-field represents a distorted image of the scatterer electron…

Condensed Matter · Physics 2009-09-29 S. Marchesini , C. S. Fadley , F. J. Garcia de Abajo

Synthetic Aperture Radar (SAR) provides all-weather, high-resolution imaging capabilities, but its unique imaging mechanism often requires expert interpretation, limiting its widespread applicability. Translating SAR images into more easily…

Computer Vision and Pattern Recognition · Computer Science 2024-07-09 Xinyu Bai , Feng Xu

Coherent diffraction imaging methods enable imaging beyond lens-imposed resolution limits. In these methods, the object can be recovered by minimizing an error metric that quantifies the difference between diffraction patterns as observed,…

Image and Video Processing · Electrical Eng. & Systems 2019-07-24 Saugat Kandel , S. Maddali , Marc Allain , Stephan O. Hruszkewycz , Chris Jacobsen , Youssef S G Nashed

Astigmatic Defocus Sensor is a very simple and easy technique for measuring the amount of defocus (deviation from the focal plane) present in an optical beam. The approach uses a cylindrical lens to focus the beam and the measure of the…

Optics · Physics 2023-01-24 Santau Konwar

White light spectral interferometry is applied to measure the refractive index in absorbing liquids in the spectral range from 400 to 1000 nm. We analyze the influence of absorption on the visibility of interferometric fringes and,…

Moving cameras provide multiple intensity measurements per pixel, yet often semantic segmentation, material recognition, and object recognition do not utilize this information. With basic alignment over several frames of a moving camera…

Computer Vision and Pattern Recognition · Computer Science 2020-09-24 Jia Xue , Matthew Purri , Kristin Dana

We propose a novel approach that jointly removes reflection or translucent layer from a scene and estimates scene depth. The input data are captured via light field imaging. The problem is couched as minimizing the rank of the transmitted…

Computer Vision and Pattern Recognition · Computer Science 2015-06-16 Qiaosong Wang , Haiting Lin , Yi Ma , Sing Bing Kang , Jingyi Yu

This paper presents a model-driven approach to detect image line segments. The approach incrementally detects segments on the gradient image using a linear Kalman filter that estimates the supporting line parameters and their associated…

Computer Vision and Pattern Recognition · Computer Science 2023-12-01 Berger Cyrille , Lacroix Simon

Deconvolution phase microscopy enables high-contrast visualization of transparent samples through reconstructions of their transmitted phases or refractive indexes. Herein, we propose a method to extend 2D deconvolution phase microscopy to…

Optics · Physics 2022-04-20 Herve Hugonnet , Mahn Jae Lee , Yongkeun Park

Frequency domain spectroscopy allows an experimenter to establish optical properties of solids in a wide frequency band including the technically challenging 10 THz region, and in other bands enables metrological comparison between…

Optics · Physics 2018-09-21 Steven Chick , Ben Murdin , Guy Matmon , Mira Naftaly

Recovering 3D geometry of underwater scenes is challenging because of non-linear refraction of light at the water-air interface caused by the camera housing. We present a light field-based approach that leverages properties of angular…

Computer Vision and Pattern Recognition · Computer Science 2022-04-06 Yuqi Ding , Zhang Chen , Yu Ji , Jingyi Yu , Jinwei Ye

Traditional framework of discriminative correlation filters (DCF) is often subject to undesired boundary effects. Several approaches to enlarge search regions have been already proposed in the past years to make up for this shortcoming.…

Computer Vision and Pattern Recognition · Computer Science 2019-08-08 Ziyuan Huang , Changhong Fu , Yiming Li , Fuling Lin , Peng Lu

Fourier transform is applied to annular beams of simplified flat two-level geometry: bright outer ring with a darker core. The pattern of focal beam profile (i.e. far field) is calculated and characterized with respect of its intensity…

Optics · Physics 2009-04-14 D. N. Astadjov

Vessel segmentation is crucial in many medical image applications, such as detecting coronary stenoses, retinal vessel diseases and brain aneurysms. However, achieving high pixel-wise accuracy, complete topology structure and robustness to…

Computer Vision and Pattern Recognition · Computer Science 2023-05-11 Tianyi Shi , Xiaohuan Ding , Wei Zhou , Feng Pan , Zengqiang Yan , Xiang Bai , Xin Yang

The detection reliability of weak signals is a critical issue in many astronomical contexts and may have severe consequences for determining number counts and luminosity functions, but also for optimising the use of telescope time in…

Instrumentation and Methods for Astrophysics · Physics 2016-04-06 Roberto Vio , Paola Andreani

Fourier ptychographic (FP) microscope is a coherent imaging method that can synthesize an image with a higher bandwidth using multiple low-bandwidth images captured at different spatial frequency regions. The method's demand for multiple…

Optics · Physics 2016-03-25 Jaebum Chung , Hangwen Lu , Xiaoze Ou , Haojiang Zhou , Changhuei Yang

Depth map estimation is a crucial task in computer vision, and new approaches have recently emerged taking advantage of light fields, as this new imaging modality captures much more information about the angular direction of light rays…

Computer Vision and Pattern Recognition · Computer Science 2020-08-12 Yang Chen , Martin Alain , Aljosa Smolic

The article concerns an investigation of the Fresnel diffraction characteristics of two types of phase optical elements, under Gaussian laser beam illumination. Both elements provide an azimuthal periodicity of the phase retardation. The…

Optics · Physics 2015-05-30 Suzana Topuzoski , Ljiljana Janicijevic

We present a methodology for designing metagratings for perfect anomalous refraction, based on multilayered loaded wire arrays. In recent work, it has been shown that such structures can implement perfect anomalous deflection and beam…

Applied Physics · Physics 2018-04-09 Ariel Epstein , Oshri Rabinovich

Optical coherence tomography (OCT) is a prevalent, interferometric, high-resolution imaging method with broad biomedical applications. Nonetheless, OCT images suffer from an artifact, called speckle which degrades the image quality. Digital…