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In this study, we conducted simulations to find the geometric aberrations expected for images taken by the Main Survey Camera (MSC) of the Chinese Space Station Telescope (CSST) due to its motion. As anticipated by previous work, our…

Instrumentation and Methods for Astrophysics · Physics 2024-08-26 Hui-Mei Feng , Zi-Huang Cao , Man I Lam , Ran Li , Hao Tian , Xin Zhang , Peng Wei , Xin-Feng Li , Wei Wang , Hugh R. A. Jones , Mao-Yuan Liu , Chao Liu

We report on the erosion of flat linoleum "pebbles" under steady rotation in a slurry of abrasive grit. To quantify shape as a function of time, we develop a general method in which the pebble is photographed from multiple angles with…

Soft Condensed Matter · Physics 2011-10-26 A. E. Roth , C. M. Marques , D. J. Durian

We investigate the expected correlation between the weak gravitational shear of distant galaxies and the orientation of foreground galaxies, through the use of numerical simulations. This shear-ellipticity correlation can mimic a…

Astrophysics · Physics 2009-08-18 Catherine Heymans , Martin White , Alan Heavens , Chris Vale , Ludovic Van Waerbeke

Novel Magnetic Resonance (MR) imaging modalities can quantify hemodynamics but require long acquisition times, precluding its widespread use for early diagnosis of cardiovascular disease. To reduce the acquisition times, reconstruction…

Image and Video Processing · Electrical Eng. & Systems 2022-01-12 Lauren Partin , Daniele E. Schiavazzi , Carlos A. Sing Long

In this work are reviewed several aspects of gravitational lensing produced by astrophysical bodies that strongly curve the spacetime in their vicinity. When an object with a photon sphere (e.g. a black hole) is interposed between a source…

General Relativity and Quantum Cosmology · Physics 2014-09-15 Ernesto F. Eiroa

Nowadays, three-dimensional reconstruction is used in various fields like computer vision, computer graphics, mixed reality and digital twin. The three-dimensional reconstruction of cultural heritage objects is one of the most important…

Computer Vision and Pattern Recognition · Computer Science 2024-06-24 F. S. Mortazavi , M. Saadatseresht

The polarization effect of the 31 reflections within the mirror train of an auxiliary telescope of the Very Large Telescope Interferometer is calculated as a function of pointing direction and rotator angle. With a rough estimate of the…

Instrumentation and Methods for Astrophysics · Physics 2011-03-30 Richard J. Mathar

In many applications of tomography, the acquired projections are either limited in number or contain a significant amount of noise. In these cases, standard reconstruction methods tend to produce artifacts that can make further analysis…

Numerical Analysis · Mathematics 2016-04-11 D. M. Pelt , K. J. Batenburg

Tissue deformation in ultrasound (US) imaging leads to geometrical errors when measuring tissues due to the pressure exerted by probes. Such deformation has an even larger effect on 3D US volumes as the correct compounding is limited by the…

Image and Video Processing · Electrical Eng. & Systems 2021-10-26 Zhongliang Jiang , Yue Zhou , Yuan Bi , Mingchuan Zhou , Thomas Wendler , Nassir Navab

To measure the mass of foreground objects with weak gravitational lensing, one needs to estimate the redshift distribution of lensed background sources. This is commonly done in an empirical fashion, i.e. with a reference sample of galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Daniel Gruen , Fabrice Brimioulle

Images taken by space telescopes typically have a superb spatial resolution, but a relatively poor sampling rate due to the finite CCD pixel size. Beyond the Nyquist limit, it becomes uncertain how much the pixelation effect may affect the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-06 Zhi Shen , Jun Zhang , Hekun Li , Haoran Wang , Chengliang Wei , Guoliang Li , Xiaobo Li , Zhang Ban , Dan Yue

This article adapts the framework of metamorphosis to solve inverse problems in imaging that includes joint reconstruction and image registration. The deformations in question have two components, one that is a geometric deformation moving…

Computer Vision and Pattern Recognition · Computer Science 2018-06-25 Gris Barbara , Chen Chong , Öktem Ozan

Advances in AI based computer vision has led to a significant growth in synthetic image generation and artificial image tampering with serious implications for unethical exploitations that undermine person identification and could make…

Computer Vision and Pattern Recognition · Computer Science 2022-08-05 Tahir Hassan , Aras Asaad , Dashti Ali , Sabah Jassim

The effect of ionized gas on the propagation of radio signals is known as plasma lensing. Unlike gravitational lensing, plasma lensing causes both magnification and strong de-magnification effects to background sources. We study the cross…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Xinzhong Er , Jiangchuan Yu , Adam Rogers , Shihang Liu , Shude Mao

Specular reflections pose a significant challenge for object segmentation, as their sharp intensity transitions often mislead both conventional algorithms and deep learning based methods. However, as the specular reflection must lie on the…

Image and Video Processing · Electrical Eng. & Systems 2026-02-26 Katja Kossira , Yunxuan Zhu , Jürgen Seiler , André Kaup

Upcoming weak lensing surveys will survey large cosmological volumes to measure the growth of cosmological structure with time and thereby constrain dark energy. One major systematic uncertainty in this process is the calibration of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Arun Kannawadi , Rachel Mandelbaum , Claire Lackner

We develop a comprehensive approach to simulate the deformation of mirrors and lenses due to thermal and mechanical stresses that couples efficiently to photon-based optics simulations. This expands upon previous work where we demonstrated…

Instrumentation and Methods for Astrophysics · Physics 2019-03-20 J. R. Peterson , E. Peng , C. J. Burke , G. Sembroski , J. Cheng

We generalize ERA method of PSF correction for more realistic situations. The method re-smears the observed galaxy image(galaxy image smeared by PSF) and PSF image by an appropriate function called Re-Smearing Function(RSF) to make new…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Yuki Okura , Toshifumi Futamase

We discuss the plastic behavior of an amorphous matrix reinforced by hard particles. A mesoscopic depinning-like model accounting for Eshelby elastic interactions is implemented. Only the effect of a plastic disorder is considered.…

Materials Science · Physics 2016-02-17 Botond Tyukodi , Claire A. Lemarchand , Jesper S. Hansen , Damien Vandembroucq

Visualization in the virtual image formed by dielectric microparticles has been shown to enable the distinction of objects that remain indistinguishable under direct observation. We perform the resolution analysis based on a full…