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The fast algorithms in Fourier optics have invigorated multifunctional device design and advanced imaging technologies. However, the necessity for fast computations has led to limitations in the widely used conventional Fourier methods,…

Applied Physics · Physics 2024-06-25 Zhi Li , Xuhao Luo , Jing Wang , Xin Yuan , Dongdong Teng , Qiang Song , Huigao Duan

Kernel-phase is a data analysis method based on a generalization of the notion of closure-phase invented in the context of interferometry, but that applies to well corrected diffraction dominated images produced by an arbitrary aperture.…

Instrumentation and Methods for Astrophysics · Physics 2020-04-22 Frantz Martinache , Alban Ceau , Romain Laugier , Jens Kammerer , Mamadou N'Diaye , David Mary , Nick Cvetojevic , Coline Lopez

Inhomogeneities in the refractive index of a biological sample can introduce phase aberrationsin microscopy systems, severely impairing the quality of images. Adaptive optics can be employed to correct for phase aberrations and improve…

We propose a method for automatic calibration of a traffic surveillance camera with wide-angle lenses. Video footage of a few minutes is sufficient for the entire calibration process to take place. This method takes in the height of the…

Computer Vision and Pattern Recognition · Computer Science 2020-01-22 Aman Gajendra Jain , Nicolas Saunier

The tilt, rotation, or offset of each CCD with respect to the focal plane, as well as the distortion of the focal plane itself, cause shape distortions to the observed objects, an effect typically known as field distortion (FD). We point…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Jun Zhang , Fuyu Dong , Hekun Li , Xiangchong Li , Yingke Li , Dezi Liu , Wentao Luo , Liping Fu , Guoliang Li , Zuhui Fan

In many computer vision domains, the input images must conform with the pinhole camera model, where straight lines in the real world are projected as straight lines in the image. Performing computer vision tasks on live sports broadcast…

Computer Vision and Pattern Recognition · Computer Science 2021-12-16 Igor Janos , Wanda Benesova

Diffusion-weighted magnetic resonance imaging (DW-MRI) is a non-invasive way of imaging white matter tracts in the human brain. DW-MRIs are usually acquired using echo-planar imaging (EPI) with high gradient fields, which could introduce…

Image and Video Processing · Electrical Eng. & Systems 2023-04-04 Zhangxing Bian , Muhan Shao , Aaron Carass , Jerry L. Prince

In this paper we present an algorithm for optical phase evaluation based on the wavelet transform technique. The main advantage of this method is that it requires only one fringe pattern. This algorithm is based on the use of a second…

Computational Engineering, Finance, and Science · Computer Science 2010-05-24 Mustapha Bahich , Mohamed Afifi , Elmostafa Barj

This paper addresses the challenges of wideband signal beamforming in radar systems and proposes a new calibration method. Due to operating conditions, the frequency dependent characteristics of the system can be changed, and amplitude,…

Signal Processing · Electrical Eng. & Systems 2023-06-27 Hyung-Woo Kim , Jin-woo Kim , Jin-ha Kim , JaeYoung Choi , Sangpyo Hong , Byungkwan Kim

Purpose: Field monitoring measures field perturbations, which can be accounted for during image reconstructions. In certain field monitoring environments, significant phase deviations can arise far from isocenter due to the finite extent of…

Medical Physics · Physics 2023-01-25 Paul I. Dubovan , Kyle M. Gilbert , Corey A. Baron

We present a filtering technique that can be applied to individual baselines of wide-bandwidth, wide-field interferometric data to geometrically select regions on the celestial sphere that contain primary calibration sources. The technique…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 Aaron R. Parsons , Donald C. Backer

DeepAngle is a machine learning-based method to determine the contact angles of different phases in the tomography images of porous materials. Measurement of angles in 3--D needs to be done within the surface perpendicular to the angle…

Computer Vision and Pattern Recognition · Computer Science 2022-11-29 Arash Rabbani , Chenhao Sun , Masoud Babaei , Vahid J. Niasar , Ryan T. Armstrong , Peyman Mostaghimi

Generally, wave field reconstructions obtained by phase-retrieval algorithms are noisy, blurred and corrupted by various artifacts such as irregular waves, spots, etc. These disturbances, arising due to many factors such as non-idealities…

Optics · Physics 2012-07-24 Artem Migukin , Mostafa Agour , Vladimir Katkovnik

Camera calibration is a first and fundamental step in various computer vision applications. Despite being an active field of research, Zhang's method remains widely used for camera calibration due to its implementation in popular toolboxes.…

Computer Vision and Pattern Recognition · Computer Science 2023-09-21 Ivan De Boi , Stuti Pathak , Marina Oliveira , Rudi Penne

The structural complexity and instability of many interference phase microscopy methods are the major obstacles toward high-precision phase measurement. In this vein, improving more efficient configurations as well as proposing new methods…

Optics · Physics 2020-01-08 Samira Ebrahimi , Masoomeh Dashtdar

In fringe projection profilometry, the high-order harmonics information of non-sinusoidal fringes will lead to errors in the phase estimation. In order to solve this problem, a point-wise posterior phase estimation (PWPPE) method based on…

Image and Video Processing · Electrical Eng. & Systems 2021-08-03 Cong Liu , Chuang Zhang , Zhuoyi Yin , Xiaopeng Liu , Zhihong Xu

Strong turbulence conditions create amplitude aberrations through the effects of near-field diffraction. When integrated over long optical path lengths, amplitude aberrations (seen as scintillation) can nullify local areas in the recorded…

Instrumentation and Methods for Astrophysics · Physics 2020-12-30 Justin R. Crepp , Stanimir O. Letchev , Sam J. Potier , Joshua H. Follansbee , Nicholas T. Tusay

In order to increase the efficiency of phase retrieval,Wang proposed a high-speed moire phase retrieval method.But it is used only to measure the tiny object. In view of the limitation of Wang method,we proposed a dynamic three-dimensional…

Optics · Physics 2023-10-18 Canlin Zhou , Shuchun Si , XiaoLei Li , Zhenkun Lei , Yanjie Li , Chaorui Zhang

Fluorescence imaging is an essential diagnostic tool in many fields, but diffraction-limited optical imaging at depth is limited by scattering. Here, we present a method based on multiple random illuminations, combined with a computational…

Optics · Physics 2026-03-30 Lei Zhu , Tengfei Wu , Bernhard Rauer , Hilton B. de Aguiar , Sylvain Gigan

In this work, we propose a camera self-calibration algorithm for generic cameras with arbitrary non-linear distortions. We jointly learn the geometry of the scene and the accurate camera parameters without any calibration objects. Our…

Computer Vision and Pattern Recognition · Computer Science 2021-09-03 Yoonwoo Jeong , Seokjun Ahn , Christopher Choy , Animashree Anandkumar , Minsu Cho , Jaesik Park