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Hyperspectral imaging has proven its efficiency for target detection applications but the acquisition mode and the data rate are major issues when dealing with real-time detection applications. It can be useful to use snapshot spectral…

Highly collimated betatron radiation from a laser wakefield accelerator is a promising tool for spectroscopic measurements. Therefore there is a requirement to create spectrometers suited to the unique properties of such a source. We…

Image segmentation is an inherently ill-posed problem and thus requires regularization in order to limit the search space to reasonable solutions. A majority of segmentation methods integrates these regularization terms in one way or the…

Numerical Analysis · Mathematics 2018-10-31 Uri Nahum , Philippe C. Cattin

We previously demonstrated near-field speckle scanning based x-ray imaging to be an easy-to-implement phase sensing method capable of providing both high sensitivity and high resolution. Yet, this performance combination could only be…

Medical Physics · Physics 2017-06-21 Sebastien Berujon , Eric Ziegler

Hard X-ray spectra in solar flares provide knowledge of the electron spectrum that results from acceleration and propagation in the solar atmosphere. However, the inference of the electron spectra from solar X-ray spectra is an ill-posed…

Astrophysics · Physics 2009-11-10 E. P. Kontar , M. Piana , A. M. Massone , A. G. Emslie , J. C. Brown

It is well-known in image processing that computational cost increases rapidly with the number and dimensions of the images to be processed. Several fields, such as medical imaging, routinely use numerous very large images, which might also…

Computer Vision and Pattern Recognition · Computer Science 2016-05-24 Fares Al-Qunaieer , Hamid R. Tizhoosh , Shahryar Rahnamayan

Stack-based high dynamic range (HDR) imaging is a technique for achieving a larger dynamic range in an image by combining several low dynamic range images acquired at different exposures. Minimizing the set of images to combine, while…

Computer Vision and Pattern Recognition · Computer Science 2018-06-21 Peter van Beek

The capability of the adaptive optics to correct for the segmentation error is analyzed in terms of the residual wavefront RMS and the power spectral density of the phase. The analytical model and the end-to-end simulation give…

Astrophysics · Physics 2009-11-11 Natalia Yaitskova , Christophe Verinaud

In practice, environments constantly change over time and space, posing significant challenges for object detectors trained based on a closed-set assumption, i.e., training and test data share the same distribution. To this end, continual…

Computer Vision and Pattern Recognition · Computer Science 2025-07-01 Deng Li , Aming Wu , Yang Li , Yaowei Wang , Yahong Han

In a previous paper, we reviewed theoretically some of the available processing schemes for X-ray wavefront sensing based on random modulation. We here show experimental applications of the technique for characterising both refractive and…

Instrumentation and Detectors · Physics 2020-02-24 Sebastien Berujon , Ruxandra Cojocaru , Pierre Piault , Rafael Celestre , Thomas Roth , Raymond Barrett , Eric Ziegler

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

X-ray echo spectroscopy, a space-domain counterpart of neutron spin echo, is a recently proposed inelastic x-ray scattering (IXS) technique. X-ray echo spectroscopy relies on imaging IXS spectra, and does not require x-ray…

Optics · Physics 2017-08-04 Yuri Shvyd'ko

Aligning beamlines at synchrotron light sources is a high-dimensional, expensive-to-sample optimization problem, as beams are focused using a series of dynamic optical components. Bayesian Optimization is an efficient machine learning…

Accelerator Physics · Physics 2024-08-14 Megha R. Narayanan , Thomas W. Morris

Improving angular resolution is one of X-ray astronomy's big challenges. While X-ray interferometry should eventually vastly improve broad-band angular resolution, in the near-term, X-ray telescopes will sacrifice angular resolution for…

Astrophysics · Physics 2007-05-23 Craig J. Copi , Glenn D. Starkman

X-ray mirrors with high focusing performances are in use in both mirror modules for X-ray telescopes and in synchrotron and FEL (Free Electron Laser) beamlines. A degradation of the focus sharpness arises in general from geometrical…

Optics · Physics 2013-04-05 D. Spiga , L. Raimondi , C. Svetina , M. Zangrando

Spectral imaging is an umbrella term for energy-resolved x-ray imaging in medicine. The technique makes use of the energy dependence of x-ray attenuation to either increase the contrast-to-noise ratio, or to provide quantitative image data…

Medical Physics · Physics 2021-01-05 Erik Fredenberg

For the accurate representation and reconstruction of band-limited signals on the sphere, an optimal-dimensionality sampling scheme has been recently proposed which requires the optimal number of samples equal to the number of degrees of…

Information Theory · Computer Science 2017-09-11 Wajeeha Nafees , Zubair Khalid , Rodney A. Kennedy , Jason D. McEwen

This paper proposes an automatic controller tuning framework based on linear optimal control combined with Bayesian optimization. With this framework, an initial set of controller gains is automatically improved according to a pre-defined…

Robotics · Computer Science 2017-09-21 Alonso Marco , Philipp Hennig , Jeannette Bohg , Stefan Schaal , Sebastian Trimpe

The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed Serial Crystallography method, the damage problem is addressed by distributing the total dose over…

X-ray devices are far superior to optical ones for providing nanometre spatial and attosecond temporal resolutions. Such resolution is indispensable in biology, medicine, physics, material sciences, and their applications. A bright…