English
Related papers

Related papers: A collimated beam projector for precise telescope …

200 papers

Beam hardening (BH) is one of the major artifacts that severely reduces the quality of Computed Tomography (CT) imaging. In a polychromatic X-ray beam, since low-energy photons are more preferentially absorbed, the attenuation of the beam…

Image and Video Processing · Electrical Eng. & Systems 2022-03-10 Ammar Alsaffar , Kaicong Sun , Sven Simon

Photometric calibration is essential to many computer vision applications. One of its key benefits is enhancing the performance of Visual SLAM, especially when it depends on a direct method for tracking, such as the standard KLT algorithm.…

Computer Vision and Pattern Recognition · Computer Science 2023-07-07 Jawad Haidar , Douaa Khalil , Daniel Asmar

A 2D transparency may be projected on a diffractive screen by just illuminating it with a filament lamp of the same height. Sharpness of the filament width is naturally related to sharpness on the image, but some peculiar properties makes…

Optics · Physics 2007-05-23 J. J. Lunazzi

Due to high exploitation costs and other environmental issues, it would be desirable to phase out large cinema projection systems based on standard xenon lamps in favor of laser based projection devices. Lasers provide longer lifetime and…

Applied Physics · Physics 2018-03-20 Pierre Walczak , Xavier Hachair , Stéphane Barland

With sub-microarcsecond angular accuracy, the \theia telescope will be capable of revealing the architectures of nearby exoplanetary systems down to the mass of Earth. This research addresses the challenges inherent in space astrometry…

Instrumentation and Methods for Astrophysics · Physics 2024-08-29 F. Malbet , M. Lizzana , F. Pancher , S. Soler , A. Léger , T. Lépine , G. A. Mamon , A. Sozzetti , A. Riva , D. Busonero , L. Labadie , P. -O. Lagage , R. Goullioud

We present a practical apparatus for characterizing optical aberrations of large collimation mirrors and lenses, and give a detailed analysis of wavefront-detection errors. We utilize a scanning pentaprism technique for precise measurements…

Optics · Physics 2022-05-13 Youn Seok Lee , Kimia Mohammadi , Thomas Jennewein

In view of the realistic possibility for operating high-energy polarized proton beams in future collider machines, it is highly desirable to propose for such beams, an absolute calibration allowing to measure accurately their degree of…

High Energy Physics - Phenomenology · Physics 2009-09-25 C. Bourrely , J. Soffer

All coronagraphic instruments for exoplanet high-contrast imaging need wavefront correction systems to reject optical aberrations and create sufficiently dark holes. Since the most efficient wavefront correction algorithms (controllers and…

Instrumentation and Methods for Astrophysics · Physics 2018-10-09 He Sun , N. Jeremy Kasdin , Robert Vanderbei

Camera calibration is a crucial step in photogrammetry and 3D vision applications. This paper introduces a novel camera calibration method using a designed collimator system. Our collimator system provides a reliable and controllable…

Computer Vision and Pattern Recognition · Computer Science 2025-12-19 Shunkun Liang , Banglei Guan , Zhenbao Yu , Dongcai Tan , Pengju Sun , Zibin Liu , Qifeng Yu , Yang Shang

Over the past decade, optical orbital angular momentum (OAM) modes were shown to offer advantages in optical information acquisition. Here, we introduce a new scheme for optical ranging in which depth is estimated through the angular…

Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage.…

Camera calibration is an essential prerequisite for event-based vision applications. Current event camera calibration methods typically involve using flashing patterns, reconstructing intensity images, and utilizing the features extracted…

Computer Vision and Pattern Recognition · Computer Science 2026-01-06 Zibin Liu , Banglei Guan , Yang Shang , Zhenbao Yu , Yifei Bian , Qifeng Yu

We propose a method for designing refractive optical elements for collimated beam shaping. In this method, the problem of finding a ray mapping is formulated as a linear assignment problem, which is a discrete version of the corresponding…

Scattering scanning near-field optical microscopy enables optical imaging and characterization of plasmonic devices with nanometer-scale resolution well below the diffraction limit. This technique enables developers to probe and understand…

Speckle Noise is the dominant source of error in high contrast imaging with adaptive optics system. We discuss the potential for wavefront sensing telemetry to calibrate speckle noise with sufficient precision and accuracy so that it can be…

We propose a deep neural network architecture to infer dense depth from an image and a sparse point cloud. It is trained using a video stream and corresponding synchronized sparse point cloud, as obtained from a LIDAR or other range sensor,…

Computer Vision and Pattern Recognition · Computer Science 2021-10-12 Alex Wong , Stefano Soatto

Projection mapping (PM) is a technique that enhances the appearance of real-world surfaces using projected images, enabling multiple people to view augmentations simultaneously, thereby facilitating communication and collaboration. However,…

Graphics · Computer Science 2024-06-06 Masaki Takeuchi , Hiroki Kusuyama , Daisuke Iwai , Kosuke Sato

Pulsed UV lasers can provide useful "testbeams" for observatories that use optical detectors, especially fluorescence detectors, to measure high energy cosmic-rays. The light observed by the detector is proportional to the energy of the…

Instrumentation and Methods for Astrophysics · Physics 2011-05-23 Lawrence Wiencke , Fernando Arqueros , John Compton , Maria Monasor , David Pilger , Jaime Rosado

This paper proposes a deep learning based method for colored transparent object matting from a single image. Existing approaches for transparent object matting often require multiple images and long processing times, which greatly hinder…

Computer Vision and Pattern Recognition · Computer Science 2019-10-08 Jamal Ahmed Rahim , Kwan-Yee Kenneth Wong

Fourier ptychography captures intensity images with varying source patterns (illumination angles) in order to computationally reconstruct large space-bandwidth-product images. Accurate knowledge of the illumination angles is necessary for…

Signal Processing · Electrical Eng. & Systems 2018-11-01 Regina Eckert , Zachary F. Phillips , Laura Waller