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Spectral imaging has recently gained traction for face recognition in biometric systems. We investigate the merits of spectral imaging for face recognition and the current challenges that hamper the widespread deployment of spectral sensors…

Computer Vision and Pattern Recognition · Computer Science 2020-01-06 Rumaisah Munir , Rizwan Ahmed Khan

This paper concerns a new optimization problem arising in the management of a multi-object spectrometer with a configurable slit unit. The field of view of the spectrograph is divided into contiguous and parallel spatial bands, each one…

Instrumentation and Methods for Astrophysics · Physics 2021-01-12 Juan-José Salazar-González

We present a method for speckle holography that is optimised for crowded fields. Its two key features are an iterativ improvement of the instantaneous Point Spread Functions (PSFs) extracted from each speckle frame and the (optional)…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 R. Schoedel , S. Yelda , A. Ghez , J. H. V. Girard , L. Labadie , R. Rebolo , A. Perez-Garrido , M. R. Morris

The need for high dynamic range imaging is crucial in many astronomical fields, such as extra-solar planet direct detection, extra-galactic science and circumstellar imaging. Using a high quality coronograph, dynamic ranges of up to…

Astrophysics · Physics 2016-08-30 F. Malbet , J. W. Yu , M. Shao

Speckle-based sensing exploits the rich environmental information of its high-dimensional spatial intensity patterns. However, the requirement for camera-based acquisition and subsequent electronic digitization introduces significant…

Optical speckle patterns have been widely used for illumination in computational imaging, optical sectioning microscopy, and super-resolution imaging. However, commonly used speckles satisfy Rayleigh statistics, which are not ideal for…

Vignetting in camera lenses is generally seen as something to avoid. For spectral cameras with thin-film interference filters, however, we argue that vignetting can be an advantage. When illuminated by focused light, the bandwidth of…

Optics · Physics 2020-03-27 Thomas Goossens , Bert Geelen , Andy Lambrechts , Chris Van Hoof

There are different techniques to sense the wavefront phase-distortions due to atmospheric turbulence. Curvature sensors are practical in their sensitivity being adjustable to the prevailing atmospheric conditions. Even at the best sites,…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Aglae Kellerer , Mark Chun , Christ Ftaclas

X-ray speckles have been used for a wide variety of experiments, ranging from imaging (and tomography), wavefront sensing, spatial coherence measurements all the way to x-ray photon correlation spectroscopy (XPCS) and ptychography. In the…

Medical Physics · Physics 2024-04-19 Rafael Celestre , Laurene Quenot , Christopher Ninham , Emmanuel Brun , Luca Fardin

The freedom of design of coded masks used by mask-based lensless cameras is an advantage these systems have when compared to lens-based ones. We leverage this freedom of design to propose a shape-preserving optimization scheme for a…

Image and Video Processing · Electrical Eng. & Systems 2025-10-28 Jose Reinaldo Cunha Santos A V Silva Neto , Tomoya Nakamura , Yasushi Makihara , Yasushi Yagi

We demonstrate a new versatile method for 3D super-resolution microscopy by using a deformable mirror to shape the point spread function of our microscope in a continuous and controllable way. We apply this for 3D STORM imaging of…

Optics · Physics 2014-01-07 Nicolas Piro , Thomas Pengo , Nicolas Olivier , Suliana Manley

Adaptive optical correction is an efficient technique to obtain high-resolution images of the retinal surface. A main limitation of adaptive optical correction, however, is the small size of the corrected image. For medical purposes it is…

Optics · Physics 2015-03-27 Aglae Kellerer

A new method for improving the resolution of astronomical images is presented. It is based on the principle that sampled data cannot be fully deconvolved without violating the sampling theorem. Thus, the sampled image should not be…

Astrophysics · Physics 2009-10-30 P. Magain , F. Courbin , S. Sohy

The paper presents an analysis of the possible spectra manipulation and its consequence for the specific application of XCT. The focus was on the modification of the registered spectra dominantly by the sewing/stitching method. A model…

Atomic Physics · Physics 2024-06-04 A. J. Arikkat , K. A. Janulewicz , C. M. Kim , P. Wachulak

Multispectral imaging plays an important role in many applications from astronomical imaging, earth observation to biomedical imaging. However, the current technologies are complex with multiple alignment-sensitive components, predetermined…

Optics · Physics 2021-09-17 Sujit Kumar Sahoo , Dongliang Tang , Cuong Dang

The surface figure of x-ray mirrors can be improved by differential deposition of thin films. To achieve the required corrections, WSi2 layers of variable thickness were deposited through beam-defining apertures of different openings. The…

Optics · Physics 2025-06-03 Ch. Morawe , S. Labouré , F. Perrin , A. Vivo , R. Barrett

Monocular depth predictors are typically trained on large-scale training sets which are naturally biased w.r.t the distribution of camera poses. As a result, trained predictors fail to make reliable depth predictions for testing examples…

Computer Vision and Pattern Recognition · Computer Science 2021-03-30 Yunhan Zhao , Shu Kong , Charless Fowlkes

We describe a multispeckle dynamic light scattering technique capable of resolving the motion of scattering sites in cases that this motion changes systematically with time. The method is based on the visibility of the speckle pattern…

Soft Condensed Matter · Physics 2007-05-23 R. Bandyopadhyay , A. S. Gittings , S. S. Suh , P. K. Dixon , D. J. Durian

Extreme adaptive optics systems are now in operation across the globe. These systems, capable of high order wavefront correction, deliver Strehl ratios of 90% in the near-infrared. Originally intended for the direct imaging of exoplanets,…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 Nemanja Jovanovic , Christian Schwab , Nick Cvetojevic , Olivier Guyon , Frantz Martinache

Optical instruments for measuring surface-wave characteristics provide a better spatial and temporal resolution than other methods, but they face difficulties while converting the results of indirect measurements into absolute levels of the…

Atmospheric and Oceanic Physics · Physics 2015-12-15 Boris M. Salin , Mikhail B. Salin