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Related papers: Peak-locking centroid bias in Shack-Hartmann wavef…

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We investigate the estimation of multivariate extreme models with a discrete spectral measure using spherical clustering techniques. The primary contribution involves devising a method for selecting the order, that is, the number of…

Methodology · Statistics 2025-02-20 Shiyuan Deng , He Tang , Shuyang Bai

Focus scanning is critically important in many terahertz (THz) imaging and sensing applications. A traditional single focusing transmitarray can achieve a good focus when the source is on-axis but moving the source off-axis produces a…

Applied Physics · Physics 2022-11-28 Ka Kit Kelvin Ho , Geng-Bo Wu , Bao-Jie Chen , Ka Fai Chan , Chi Hou Chan

This paper addresses the search for a fast and meaningful image segmentation in the context of $k$-means clustering. The proposed method builds on a widely-used local version of Lloyd's algorithm, called Simple Linear Iterative Clustering…

Computer Vision and Pattern Recognition · Computer Science 2018-05-30 Georg Maierhofer , Daniel Heydecker , Angelica I. Aviles-Rivero , Samar M. Alsaleh , Carola-Bibiane Schönlieb

The deep image prior showed that a randomly initialized network with a suitable architecture can be trained to solve inverse imaging problems by simply optimizing it's parameters to reconstruct a single degraded image. However, it suffers…

Image and Video Processing · Electrical Eng. & Systems 2022-01-03 Zenglin Shi , Pascal Mettes , Subhransu Maji , Cees G. M. Snoek

We demonstrate a wavefront sensor based on the compressive sensing, single-pixel camera. Using a high-resolution spatial light modulator (SLM) as a variable waveplate, we weakly couple an optical field's transverse-position and polarization…

Optics · Physics 2014-07-30 Gregory A. Howland , Daniel J. Lum , John C. Howell

Parametric modeling of galaxy cluster density profiles from weak lensing observations leads to a mass bias, whose detailed understanding is critical in deriving accurate mass-observable relations for constraining cosmological models.…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-17 Martin W. Sommer , Tim Schrabback , Douglas E. Applegate , Stefan Hilbert , Behzad Ansarinejad , Benjamin Floyd , Sebastian Grandis

Wave-front sensing from focal plane multiple images is a promising technique for high-contrast imaging systems. However, the wave-front error of an optics system can be properly reconstructed only when it is very small. This paper presents…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Jiangpei Dou , Deqing Ren , Yongtian Zhu

Direct imaging of Earth-like exoplanets requires high contrast imaging capability and high angular resolution. Primary mirror segmentation is a key technological solution for large-aperture telescopes because it opens the path toward…

Instrumentation and Methods for Astrophysics · Physics 2016-06-10 Pierre Janin-Potiron , Patrice Martinez , Pierre Baudoz , Marcel Carbillet

Pattern matching between target electron backscatter patterns (EBSPs) and dynamically simulated EBSPs was used to determine the pattern centre (PC) and crystal orientation, using a global optimisation algorithm. Systematic analysis of error…

Materials Science · Physics 2019-04-16 Tomohito Tanaka , Angus J. Wilkinson

Wavefront sensors are an important tool to characterize coherent beams of extreme ultraviolet radiation. However, conventional Hartmann-type sensors do not allow for independent wavefront characterization of different spectral components…

Instrumentation and Detectors · Physics 2018-04-04 L. Freisem , G. S. M. Jansen , D. Rudolf , K. S. E. Eikema , S. Witte

Detectors inherently capable of resolving photon numbers have undergone a significant development recently, and this is expected to affect multiplexed periodic single-photon sources where such detectors can find their applications. We…

Quantum Physics · Physics 2020-07-29 Ferenc Bodog , Matyas Mechler , Matyas Koniorczyk , Peter Adam

Focal plane wavefront sensing is an elegant solution for wavefront sensing since near-focal images of any source taken by a detector show distortions in the presence of aberrations. Non-Common Path Aberrations and the Low Wind Effect both…

We review the well-known matched filter method for the detection of point sources in astronomical images. This is shown to be optimal (that is, to saturate the Cramer--Rao bound) under stated conditions that are very strong: an isolated…

Instrumentation and Methods for Astrophysics · Physics 2021-01-01 Dustin Lang , David W. Hogg

In this letter, a fast Fourier transform (FFT)-enhanced low-complexity super-resolution sensing algorithm for near-field source localization with both angle and range estimation is proposed. Most traditional near-field source localization…

Signal Processing · Electrical Eng. & Systems 2024-11-26 Yuxiao Wu , Huizhi Wang , Yong Zeng

When Charge Coupled Devices are used for scientific observations, their dark signal is a hindrance. In their pristine state, most CCD pixels are `cool'; they exhibit low, quasi uniform dark current, which can be estimated and corrected for.…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 J. -F. Hochedez , C. Timmermans , A. Hauchecorne , M. Meftah

The Hartmann test is a method used to measure the wavefront error in a focal optical system, wherein a mask with a pattern of small holes is placed at the system's aperture stop. By taking an image at a defocused plane, the differences…

In this paper, we present an optimal metric function on average, which leads to a significantly low decoding computation while maintaining the superiority of the polarization-adjusted convolutional (PAC) codes' error-correction performance.…

Information Theory · Computer Science 2020-12-11 Mohsen Moradi

With an extremely high dimensionality, the spatial degree of freedom of entangled photons is a key tool for quantum foundation and applied quantum techniques. To fully utilize the feature, the essential task is to experimentally…

The moment method is an image analysis technique for sub-pixel estimation of particle positions. The total error in the calculated particle position includes effects of pixel locking and random noise in each pixel. Pixel locking, also known…

Plasma Physics · Physics 2011-05-23 Yan Feng , J. Goree , Bin Liu

Keypoint detection and description play a central role in computer vision. Most existing methods are in the form of scene-level prediction, without returning the object classes of different keypoints. In this paper, we propose the…

Computer Vision and Pattern Recognition · Computer Science 2022-02-04 Chengliang Zhong , Chao Yang , Jinshan Qi , Fuchun Sun , Huaping Liu , Xiaodong Mu , Wenbing Huang
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