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The goal of synthetic aperture imaging is to estimate the reflectivity of a remote region of interest by processing data gathered with a moving sensor which emits periodically a signal and records the backscattered wave. We introduce and…

Image and Video Processing · Electrical Eng. & Systems 2019-07-05 Liliana Borcea , Josselin Garnier

We propose a new ray-tracing algorithm to measure the weak lensing shear and convergence fields directly from N-body simulations. We calculate the deflection of the light rays lensed by the 3-D mass density field or gravitational potential…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Baojiu Li , Lindsay J. King , Gong-Bo Zhao , HongSheng Zhao

Intelligent reflecting surface (IRS), which consists of a large number of tunable reflective elements, is capable of enhancing the wireless propagation environment in a cellular network by intelligently reflecting the electromagnetic waves…

Signal Processing · Electrical Eng. & Systems 2021-06-10 Tao Jiang , Hei Victor Cheng , Wei Yu

We aim at estimating the fundamental matrix in two views from five correspondences of rotation invariant features obtained by e.g.\ the SIFT detector. The proposed minimal solver first estimates a homography from three correspondences…

Computer Vision and Pattern Recognition · Computer Science 2018-03-02 Daniel Barath

Recovering the shape and appearance of real-world objects from natural 2D images is a long-standing and challenging inverse rendering problem. In this paper, we introduce a novel hybrid differentiable rendering method to efficiently…

Computer Vision and Pattern Recognition · Computer Science 2023-08-22 Xiangyang Zhu , Yiling Pan , Bailin Deng , Bin Wang

High-contrast imaging from space must overcome two major noise sources to successfully detect a terrestrial planet angularly close to its parent star: photon noise from diffracted star light, and speckle noise from star light scattered by…

Astrophysics · Physics 2009-11-13 Pascal J. Borde , Wesley A. Traub

This study introduces a novel unsupervised medical image feature extraction method that employs spatial stratification techniques. An objective function based on weight is proposed to achieve the purpose of fast image recognition. The…

Image and Video Processing · Electrical Eng. & Systems 2024-06-28 Qishi Zhan , Dan Sun , Erdi Gao , Yuhan Ma , Yaxin Liang , Haowei Yang

Inverse rendering aims to reconstruct geometry and reflectance of objects from images. Despite recent progress, existing methods often produces inaccurate reconstructions that are sensitive to ambient illumination conditions. Here we…

Computer Vision and Pattern Recognition · Computer Science 2026-05-29 Hoon-Gyu Chung , Jinnyeong Kim , Hyunwoo Kang , Seung-Hwan Baek

Quantitative inversion algorithms allow for the reconstruction of electrical properties (such as permittivity, and conductivity) for every point in a scene. However, they are challenging to use on measured datasets due to the need to know…

Signal Processing · Electrical Eng. & Systems 2025-05-15 Zacharie Idriss , Raghu Raj

Ray tracing is widely employed to model the propagation of radio-frequency (RF) signal in complex environment. The modelling performance greatly depends on how accurately the target scene can be depicted, including the scene geometry and…

Computer Vision and Pattern Recognition · Computer Science 2025-01-07 Haifeng Jia , Xinyi Chen , Yichen Wei , Yifei Sun , Yibo Pi

Neural radiance fields (NeRFs) have become a ubiquitous tool for modeling scene appearance and geometry from multiview imagery. Recent work has also begun to explore how to use additional supervision from lidar or depth sensor measurements…

Computer Vision and Pattern Recognition · Computer Science 2024-04-09 Anagh Malik , Parsa Mirdehghan , Sotiris Nousias , Kiriakos N. Kutulakos , David B. Lindell

GeRaF is the first method to use neural implicit learning for near-range 3D geometry reconstruction from radio frequency (RF) signals. Unlike RGB or LiDAR-based methods, RF sensing can see through occlusion but suffers from low resolution…

Computer Vision and Pattern Recognition · Computer Science 2026-05-29 Jiachen Lu , Hailan Shanbhag , Haitham Al Hassanieh

Precise camera localization is a critical task in XR applications and robotics. Using only the camera captures as input to a system is an inexpensive option that enables localization in large indoor and outdoor environments, but it presents…

Computer Vision and Pattern Recognition · Computer Science 2025-04-15 Asterios Reppas , Grigorios-Aris Cheimariotis , Panos K. Papadopoulos , Panagiotis Frasiolas , Dimitrios Zarpalas

This paper presents a radar cross-section (RCS)-based statistical recognition system for identifying/ classifying unmanned aerial vehicles (UAVs) at microwave frequencies. First, the paper presents the results of the vertical (VV) and…

Signal Processing · Electrical Eng. & Systems 2021-02-25 Martins Ezuma , Chethan Kumar Anjinappa , Mark Funderburk , Ismail Guvenc

Heatmap regression (HR) has become one of the mainstream approaches for face alignment and has obtained promising results under constrained environments. However, when a face image suffers from large pose variations, heavy occlusions and…

Computer Vision and Pattern Recognition · Computer Science 2020-12-30 Jun Wan , Zhihui Lai , Jun Liu , Jie Zhou , Can Gao

The description, imagery and interpretation of cloud scenes by remote sensing datasets from Earth-orbiting satellites have become a great debate for several decades. Presently, there are many models for cloud detection and its…

Space Physics · Physics 2020-10-07 Rehan Siddiqui , Rajinder K. Jagpal , Sanjar M. Abrarov , Brendan M. Quine

This paper presents a method for estimating the resolution of a digital holographic microscope using neural network analysis of reconstructed images. The spectral bandwidth of the source ($\Delta \lambda$) is used as a controlled image…

Optics · Physics 2026-05-12 A. G. Fedorov

We describe a system being developed for measuring the shapes of the mirrors of the Fred Young Submillimeter Telescope (FYST), now under construction for the CCAT Observatory. "Holographic" antenna-measuring techniques are an efficient and…

Instrumentation and Methods for Astrophysics · Physics 2021-03-16 Xiaodong Ren , Pablo Astudillo , Urs U. Graf , Richard E. Hills , Sebastian Jorquera , Bojan Nikolic , Stephen C. Parshley , Nicolás Reyes , Lars Weikert

Wavefront sensing with a thin diffuser has emerged as a potential low-cost alternative to a lenslet array for aberrometry. Diffuser wavefront sensors (DWS) have previously relied on tracking speckle displacement and consequently require…

Optics · Physics 2019-01-01 Gregory N. McKay , Faisal Mahmood , Nicholas J. Durr

Camera relocalization involving a prior 3D reconstruction plays a crucial role in many mixed reality and robotics applications. Estimating the camera pose directly with respect to pre-built 3D models can be prohibitively expensive for…

Computer Vision and Pattern Recognition · Computer Science 2022-12-06 Thuan B. Bui , Dinh-Tuan Tran , Joo-Ho Lee