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Related papers: Multi-windowed defocused speckle photographic syst…

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Capturing more information, e.g. geometry and material, using optical cameras can greatly help the perception and understanding of complex scenes. This paper proposes a novel method to capture the spectral and light field information…

Image and Video Processing · Electrical Eng. & Systems 2018-02-27 Qian Huang , Yunqian Li , Linsen Chen , Xiaoming Zhong , Jinli Suo , Zhan Ma , Tao Yue , Xun Cao

This paper presents a new method to obtain the deformation distribution on the main reflector of an antenna only by measuring the electric intensity on a spherical surface with the focal point as the center of the sphere, regardless of…

Instrumentation and Methods for Astrophysics · Physics 2021-12-08 Qian Ye , Boyang Wang , Qiang Yao , Jinqing Wang , Qinghui Liu , Zhiqiang Shen

Context: The technique of disentangling has been applied to numerous high-precision studies of spectroscopic binaries and multiple stars. Although, its possibilities have not yet been fully understood and exploited. Aims: Theoretical…

Instrumentation and Methods for Astrophysics · Physics 2009-11-13 Petr Hadrava

Recent advances in optical metasurfaces enable control of the wavefront, polarization and dispersion of optical waves beyond the capabilities of conventional diffractive optics. An optical design space that is poised to highly benefit from…

In this paper, we study the spectral properties of re-parameterized light field. Following previous studies of the light field spectrum, which notably provided sampling guidelines, we focus on the two plane parameterization of the light…

Computer Vision and Pattern Recognition · Computer Science 2022-09-08 Martin Alain , Aljosa Smolic

Metasurfaces advanced the field of optics by reducing the thickness of optical components and merging multiple functionalities into a single layer device. However, this generally comes with a reduction in performance, especially for…

Speckle metrology exploits the high sensitivity of scattered fields to parameters of interest, yet this also leaves measurements vulnerable to unintended perturbations. Here we employ transmission matrix formalism to engineer light fields…

Optics · Physics 2026-04-08 Hal Gee , Morgan Facchin , Graham D. Bruce

In depth from defocus (DFD), when images are captured with different camera parameters, a relative magnification is induced between them. Image warping is a simpler solution to account for magnification than seemingly more accurate optical…

Computer Vision and Pattern Recognition · Computer Science 2012-11-06 Arnav Bhavsar

Precision pose detection is increasingly demanded in fields such as personal fabrication, Virtual Reality (VR), and robotics due to its critical role in ensuring accurate positioning information. However, conventional vision-based systems…

Emerging Technologies · Computer Science 2024-10-10 Ziyang Chen , Mustafa Doğa Doğan , Josef Spjut , Kaan Akşit

In two-dimensional spectrographs, the optical distortions in the spatial and dispersion directions produce variations in the sub-pixel sampling of the background spectrum. Using knowledge of the camera distortions and the curvature of the…

Astrophysics · Physics 2009-12-08 Daniel D. Kelson

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…

This study explores the use of photometric techniques (shape-from-shading and uncalibrated photometric stereo) for upsampling the low-resolution depth map from an RGB-D sensor to the higher resolution of the companion RGB image. A…

Computer Vision and Pattern Recognition · Computer Science 2019-06-26 Bjoern Haefner , Songyou Peng , Alok Verma , Yvain Quéau , Daniel Cremers

This is the third article in a series of three dealing with the exploitation of speckle for imaging purposes. In complex media, a fundamental limit is the multiple scattering phenomenon that completely blurs the imaging process in depth.…

Applied Physics · Physics 2026-02-06 Elsa Giraudat , Flavien Bureau , William Lambert , Mathias Fink , Alexandre Aubry

In order to increase the corrected field of view of an adaptive optics (AO) system, several deformable mirrors (DM) have to be placed in the conjugate planes of the dominant turbulent layers (multi-conjugate adaptive optics, MCAO [Beckers…

Astrophysics · Physics 2022-04-20 T. Berkefeld , A. Glindemann , S. Hippler

Geometrically decorated two-dimensional (2D) discrete surfaces can be more effective than conventional smooth reflectors in managing wave radiation. Constructive non-specular wave scattering permits the scattering angle to be other than…

We discuss a new technology that promises large inexpensive mirrors. We argue that it should be possible to tilt a rotating viscous liquid by perhaps as much as a few tens of degrees. The tilted liquid parabolic surface is used as the…

Astrophysics · Physics 2007-05-23 Ermanno F. Borra , Anna Ritcey , Etienne Artigau

A high accuracy photometric reduction method is needed to take full advantage of the potential of the transit method for the detection and characterization of exoplanets, especially in deep crowded fields. In this context, we present…

Astrophysics · Physics 2007-05-23 M. Gillon , P. Magain , V. Chantry , G. Letawe , S. Sohy , F. Courbin , F. Pont , C. Moutou

Speckle is a multiplicative noise which affects all coherent imaging modalities including Synthetic Aperture Radar (SAR) images. The presence of speckle degrades the image quality and adversely affects the performance of SAR image…

Image and Video Processing · Electrical Eng. & Systems 2023-06-21 Malsha V. Perera , Nithin Gopalakrishnan Nair , Wele Gedara Chaminda Bandara , Vishal M. Patel

It is a challenge for Phase Measurement Profilometry (PMP) to measure objects with a large range of reflectivity variation across the surface. Saturated or dark pixels in the deformed fringe patterns captured by the camera will lead to…

Computer Vision and Pattern Recognition · Computer Science 2016-11-23 Minmin Wang , Guangliang Du , Canlin Zhou , Chaorui Zhang , Shuchun Si , Hui Li , Zhenkun Lei , YanJie Li

Synthetic aperture radar (SAR) images are affected by a spatially-correlated and signal-dependent noise called speckle, which is very severe and may hinder image exploitation. Despeckling is an important task that aims at removing such…

Image and Video Processing · Electrical Eng. & Systems 2021-05-04 Giulia Fracastoro , Enrico Magli , Giovanni Poggi , Giuseppe Scarpa , Diego Valsesia , Luisa Verdoliva