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Nested multilayer mirrors are commonly used in X-ray telescope structures to increase the collecting area. To balance the difficulty and cost of producing these mirrors, the classical Wolter-I structure has previously been replaced with a…

Instrumentation and Methods for Astrophysics · Physics 2017-11-22 Sheng-Hao Chen , Shuang Ma , Zhan-Shan Wang

Multi-view stereo (MVS) reconstruction is essential for creating 3D models. The approach involves applying epipolar rectification followed by dense matching for disparity estimation. However, existing approaches face challenges in applying…

Computer Vision and Pattern Recognition · Computer Science 2022-04-11 Mostafa Elhashash , Rongjun Qin

In this work, we compare one-step and two-step approaches for X-ray computed tomography (CT) scatter correction and density reconstruction. X-ray CT is an important imaging technique in medical and industrial applications. In many cases,…

Image and Video Processing · Electrical Eng. & Systems 2023-01-11 Alexander N. Sietsema , Michael T. McCann , Marc L. Klasky , Saiprasad Ravishankar

The quality of images of the Sun obtained from the ground are severely limited by the perturbing effect of the turbulent Earth's atmosphere. The post-facto correction of the images to compensate for the presence of the atmosphere require…

Solar and Stellar Astrophysics · Physics 2018-12-05 A. Asensio Ramos , J. de la Cruz Rodriguez , A. Pastor Yabar

Matching deformable objects using their shapes is an important problem in computer vision since shape is perhaps the most distinguishable characteristic of an object. The problem is difficult due to many factors such as intra-class…

Computer Vision and Pattern Recognition · Computer Science 2015-04-28 Smit Marvaniya , Raj Gupta , Anurag Mittal

Precise knowledge of X-ray diffraction profile shape is crucial in the investigation of the properties of matter in crystals powder. Line-broadening analysis is a pre-processing step in most of the full powder pattern fitting softwares.…

Spectral Theory · Mathematics 2007-05-23 M. Ladisa , A. Lamura , T. Laudadio , G. Nico

The focusing performance of X-ray optics (conveniently expressed in terms of HEW, Half Energy Width) strongly depend on both mirrors deformations and photon scattering caused by the microroughness of reflecting surfaces. In particular, the…

Astrophysics · Physics 2007-11-28 Daniele Spiga

A shearing interferometer is presented which uses polarization control to shear the wavefront and to modulate the interference pattern. The shear is generated by spatial walk-off in a birefringent crystal. By adjusting the orientation of…

Optics · Physics 2012-12-11 Peter Beyersdorf , Mark Cordier

Solving crystal structures from powder X-ray diffraction (XRD) is a central challenge in materials characterization. In this work, we study the powder XRD-to-structure mapping using gradient descent optimization, with the goal of recovering…

Materials Science · Physics 2025-12-04 Nofit Segal , Akshay Subramanian , Mingda Li , Benjamin Kurt Miller , Rafael Gomez-Bombarelli

Following the recent developement of Fourier ptychographic microscopy (FPM) in the visible range by Zheng et al. (2013), we propose an adaptation for hard x-rays. FPM employs ptychographic reconstruction to merge a series of low-resolution,…

Instrumentation and Detectors · Physics 2016-09-27 H. Simons , H. F. Poulsen , J. P. Guigay , C. Detlefs

Computationally removing the motion blur introduced by camera shake or object motion in a captured image remains a challenging task in computational photography. Deblurring methods are often limited by the fixed global exposure time of the…

Image and Video Processing · Electrical Eng. & Systems 2022-04-18 Cindy M. Nguyen , Julien N. P. Martel , Gordon Wetzstein

Three-photon (3P) microscopy is getting traction due to its superior performance in deep tissues. Yet, aberrations and light scattering still pose one of the main limitations in the attainable depth ranges for high-resolution imaging. Here,…

This paper presents a novel technique for camera calibration using a single view that incorporates a spherical mirror. Leveraging the distinct characteristics of the sphere's contour visible in the image and its reflections, we showcase the…

Computer Vision and Pattern Recognition · Computer Science 2025-03-18 Nissim Barzilay , Ofek Narinsky , Michael Werman

In this paper, a method for solving the initial structure of an off-axis multi-mirror system applied to extreme ultraviolet (EUV) lithography using a paraxial ray-tracing algorithm based on Seidel aberration theory is proposed. By tracing…

Optics · Physics 2022-03-07 Wei Tan , Donglin Ma

Dielectric mirrors comprising thin-film multilayers are widely used in optical experiments because they can achieve substantially higher reflectance compared to metal mirrors. Here we investigate potential problems that can arise when…

Optical beams and starlight distorted by atmospheric turbulence can be corrected with adaptive optics systems to enable efficient coupling into single-mode fibers. Deformable mirrors, used to flatten the wavefront in astronomical…

In this paper, we propose a global method for estimating the motion of a camera which films a static scene. Our approach is direct, fast and robust, and deals with adjacent frames of a sequence. It is based on a quadratic approximation of…

Computer Vision and Pattern Recognition · Computer Science 2008-09-29 Claire Jonchery , Françoise Dibos , Georges Koepfler

The development of synchrotron radiation light sources has been going on for decades. Recently, X-ray free-electron lasers as well as the fourth-generation synchrotron radiation sources based on multiple bend achromat lattices are…

Accelerator Physics · Physics 2023-11-29 Zengguang Tang

Geometric rectification of images of distorted documents finds wide applications in document digitization and Optical Character Recognition (OCR). Although smoothly curved deformations have been widely investigated by many works, the most…

Computer Vision and Pattern Recognition · Computer Science 2022-12-19 Dong Luo , Pengbo Bo

Improvements in X-ray optics critically depend on the measurement of their optical performance. The knowledge of wavefront aberrations, for example, can be used to improve the fabrication of optical elements or to design phase correctors to…