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Related papers: Accuracy of Shack-Hartmann wavefront sensor using …

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Accurate speed-of-sound (SoS) estimation is crucial for ultrasound image formation, yet conventional systems often rely on an assumed value for imaging. We propose to leverage conventional image analysis techniques and metrics as a novel…

Image and Video Processing · Electrical Eng. & Systems 2026-04-08 Roman Denkin , Orcun Goksel

Noise is one of the major problems that hinder an effective texture analysis of disease in medical images, which may cause variability in the reported diagnosis. In this paper seven texture measurement methods (two wavelet, two model and…

Computer Vision and Pattern Recognition · Computer Science 2015-12-29 Omar Sultan Al-Kadi

We study imaging with an array of sensors that probes a medium with single frequency electromagnetic waves and records the scattered electric field. The medium is known and homogenous except for some small and penetrable inclusions. The…

Analysis of PDEs · Mathematics 2016-09-21 Liliana Borcea , Josselin Garnier

Presented is a novel way to combine snapshot compressive imaging and lateral shearing interferometry in order to capture the spatio-spectral phase of an ultrashort laser pulse in a single shot. A deep unrolling algorithm is utilised for the…

High-contrast imaging provided by a coronagraph is critical for the direction imaging of the Earth-like planet orbiting its bright parent star. A major limitation for such direct imaging is the speckle noise that is induced from the…

Instrumentation and Methods for Astrophysics · Physics 2015-10-14 JiangPei Dou , DeQing Ren , YongTian Zhu , Xi Zhang

Mitral valve repair is a very difficult operation, often requiring experienced surgeons. The doctor will insert a prosthetic ring to aid in the restoration of heart function. The location of the prosthesis' sutures is critical. Obtaining…

Computer Vision and Pattern Recognition · Computer Science 2021-10-13 Huifeng Yao , Ziyu Guo , Yatao Zhang , Xiaomeng Li

Purpose: Using linear transformation of the data allows studying detectability of an imaging system on a large number of signals. An appropriate transformation will produce a set of signals with different contrast and different frequency…

Medical Physics · Physics 2021-04-20 Antonio González-López

Direct detection of exoplanets requires high dynamic range imaging. Coronagraphs could be the solution, but their performance in space is limited by wavefront errors (manufacturing errors on optics, temperature variations, etc.), which…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Raphael Galicher , Pierre Baudoz , Gerard Rousset , Julien Totems , Marion Mas

A novel approach to improving the performances of confocal scanning imaging is proposed. We experimentally demonstrate its feasibility using acoustic waves. It relies on a new way to encode spatial information using the temporal dimension.…

This study presents a bio inspired signal processing framework for robust Underwater Acoustic Target Recognition (UATR). The latest state of the art methods often fail to resolve dense low frequency harmonic structures in vessel propulsion…

Sound · Computer Science 2026-05-07 Rajeshwar Tripathi , Sandeep Kumar , Monika Aggarwal , Neel Kanth Kundu

Consistent operation of adaptive optics (AO) systems requires the use of a wavefront sensor (WFS) with high sensitivity and low noise. The nonlinear curvature WFS (nlCWFS) has been shown both in simulations and lab experiments to be more…

Instrumentation and Methods for Astrophysics · Physics 2023-12-05 Sam Potier , Justin Crepp , Stanimir Letchev

In adaptive optics, the measurement of spatial coherence length helps in deciding the optimum design parameters of a Shack Hartmann Sensor (SHS). Two methods of estimating the spatial coherence length of optical wavefronts are presented.…

Instrumentation and Methods for Astrophysics · Physics 2009-11-08 Akondi Vyas , M. B. Roopashree , B. Raghavendra Prasad

Exoplanet detection and characterization through extreme adaptive optics (ExAO) is a key science goal of future extremely large telescopes. This achievement, however, will be limited in sensitivity by both quasi-static wavefront errors and…

Earth and Planetary Astrophysics · Physics 2018-07-18 Benjamin L. Gerard , Christian Marois , Raphaël Galicher , Jean-Pierre Véran

Dedicated application-specific CT systems are popular solutions to high-resolution clinical needs. Some applications, such as mammography and extremities imaging, require spatial resolution beyond current capabilities. Thorough…

Medical Physics · Physics 2017-06-28 Steven Tilley , Wojciech Zbijewski , J. Webster Stayman

Breast ultrasound (US) is an effective imaging modality for breast cancer detec-tion and diagnosis. The structural characteristics of breast lesion play an im-portant role in Computer-Aided Diagnosis (CAD). In this paper, a novel…

Image and Video Processing · Electrical Eng. & Systems 2020-06-16 Erlei Zhang , Zi Yang , Stephen Seiler , Mingli Chen , Weiguo Lu , Xuejun Gu

Multi-source stationary computed tomography (MSS-CT) offers significant advantages in medical and industrial applications due to its gantry-less scan architecture and/or capability of simultaneous multi-source emission. However, the lack of…

Medical Physics · Physics 2025-01-20 Yingxian Xia , Zhiqiang Chen , Li Zhang , Yuxiang Xing , Hewei Gao

The weak measurement wavefront sensor detects the phase gradient of light like the Shack-Hartmann sensor does. However, the use of one thin birefringent crystal to displace light beams results in a wavelength-dependent phase difference…

Optics · Physics 2022-05-27 Yi Zheng , Mu Yang , Zheng-Hao Liu , Jin-Shi Xu , Chuan-Feng Li , Guang-Can Guo

An adaptive optics system with a single deformable mirror is being implemented on the THEMIS 90cm solar telescope. This system is designed to operate in the visible and is required to be as robust as possible in order to deliver the best…

Instrumentation and Methods for Astrophysics · Physics 2021-01-11 Michel Tallon , Éric Thiébaut , Maud Langlois , Bernard Gelly , Richard Douet , Clémentine Béchet , Loïc Denis , Gil Moretto

Breast lesion detection in ultrasound video is critical for computer-aided diagnosis. However, detecting lesion in video is quite challenging due to the blurred lesion boundary, high similarity to soft tissue and lack of video annotations.…

Computer Vision and Pattern Recognition · Computer Science 2019-07-17 Sihong Chen , Weiping Yu , Kai Ma , Xinlong Sun , Xiaona Lin , Desheng Sun , Yefeng Zheng

Wavefront shaping is a technique for directing light through turbid media. The theoretical aspects of wavefront shaping are well understood, and under near-ideal experimental conditions, accurate predictions for the expected signal…

Optics · Physics 2024-07-01 Bahareh Mastiani , Daniël W. S. Cox , Ivo M. Vellekoop