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

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In this paper, a novel method for edge detection of microcalcification clusters in mammogram images is presented using the concept of Fractal Dimension and Hurst co-efficient that enables to locate the microcalcifications in the mammograms.…

Computer Vision and Pattern Recognition · Computer Science 2013-05-01 P. Shanmugavadivu , V. Sivakumar

Capturing global contextual information plays a critical role in breast ultrasound (BUS) image classification. Although convolutional neural networks (CNNs) have demonstrated reliable performance in tumor classification, they have inherent…

Image and Video Processing · Electrical Eng. & Systems 2023-08-07 Bryar Shareef , Min Xian , Aleksandar Vakanski , Haotian Wang

The nonlinear curvature wavefront sensor (nlCWFS) has been shown to be a promising alternative to existing wavefront sensor designs. Theoretical studies indicate that the inherent sensitivity of this device could offer up to a factor of 10…

Instrumentation and Methods for Astrophysics · Physics 2022-09-02 Stanimir Letchev , Jonathan Crass , Justin R. Crepp , Sam Potier

Shack Hartmann Sensor (SHS) is inflicted with significant background noise that deteriorates the wave-front reconstruction accuracy. In this paper, a simple method to remove the back ground noise with the use of Zernike polynomials is…

Instrumentation and Methods for Astrophysics · Physics 2011-09-14 Akondi Vyas , M B Roopashree , B Raghavendra Prasad

Radar-based materials detection received significant attention in recent years for its potential inclusion in consumer and industrial applications like object recognition for grasping and manufacturing quality assurance and control. Several…

Signal Processing · Electrical Eng. & Systems 2022-02-11 Rami N. Khushaba , Andrew J. Hill

Atmospheric turbulence degrades the quality of astronomical observations in ground-based telescopes, leading to distorted and blurry images. Adaptive Optics (AO) systems are designed to counteract these effects, using atmospheric…

Instrumentation and Methods for Astrophysics · Physics 2025-04-27 Jeffrey Smith , Taisei Fujii , Jesse Cranney , Charles Gretton

Deep, high-resolution imaging is essential for unraveling biological complexity and advancing medical diagnostics, yet scattering fundamentally limits optical methods. Among the most promising approaches, photoacoustic imaging achieves…

Pixel intensity is a widely used feature for clustering and segmentation algorithms, the resulting segmentation using only intensity values might suffer from noises and lack of spatial context information. Wavelet transform is often used…

Image and Video Processing · Electrical Eng. & Systems 2019-07-09 Junyu Chen , Eric C. Frey

Classification of damages in honeycomb composite sandwich structure (HCSS) is important to decide remedial actions. However, previous studies have only detected damages using deviations of monitoring signal from healthy (baseline) using a…

Signal Processing · Electrical Eng. & Systems 2023-11-08 Shruti Sawant , Jeslin Thalapil , Siddharth Tallur , Sauvik Banerjee , Amit Sethi

Accurate measurement of light wavelength is critical for applications in spectroscopy, optical communication, and semiconductor manufacturing, ensuring precision and consistency of sensing, high-speed data transmission and device…

Ultrasound imaging systems rely on accurate point spread function (PSF) estimation to support advanced image quality enhancement techniques such as deconvolution and speckle reduction. Phase aberration, caused by sound speed inhomogeneity…

Signal Processing · Electrical Eng. & Systems 2025-02-24 Wei-Hsiang Shen , Yu-An Lin , Meng-Lin Li

Band bending is a central concept in solid-state physics that arises from local variations in charge distribution especially near semiconductor interfaces and surfaces. Its precision measurement is vital in a variety of contexts from the…

Inspired by the extensive application of terahertz imaging technologies in the field of aerospace, we exploit a terahertz frequency modulated continuous wave imaging method with continuous wavelet transform algorithm to detect a multilayer…

Signal Processing · Electrical Eng. & Systems 2019-05-30 Yu Zhou

A variety of spherical crystal x-ray imager (SCXI) diagnostics have been developed and fielded on Magnetized Liner Inertial Fusion (MagLIF) experiments at the Sandia National Laboratories Z-facility. These different imaging modalities…

The nonlinear curvature wavefront sensor (nlCWFS) uses multiple (typically four) out-of-focus images to reconstruct the phase and amplitude of a propagating light beam. Because these images are located between the pupil and focal planes,…

Instrumentation and Methods for Astrophysics · Physics 2024-07-23 Caleb A. Abbott , Justin R. Crepp , Stanimir O. Letchev , Connor M. Smith

A method for producing a laser guide star wavefront sensor for adaptive optics with reduced focal anisoplanatism is presented. A theoretical analysis and numerical simulations have been carried out and the results are presented. The…

Astrophysics · Physics 2009-11-11 T. Butterley , G. D. Love , R. W. Wilson , R. M. Myers , T. J. Morris

Astronomers working with faint targets will benefit greatly from improved image quality on current and planned ground-based telescopes. At present, most adaptive optic systems are targeted at the highest resolution with bright guide stars.…

Instrumentation and Methods for Astrophysics · Physics 2020-01-30 Craig Mackay

Wave front sensing of the surface of equal phase for a propagating electromagnetic wave is a vital technology in fields ranging from real time adaptive optics, to high accuracy metrology, to medical optometry. We have developed a new method…

Optics · Physics 2025-10-01 C. L. Carilli , L. Torino , B. Nikolic , N. Thyagarajan , U. Iriso

Silicon photonic wavefront phase-tilt sensors for wavefront monitoring using surface coupling grating arrays are demonstrated. The first design employs the intrinsic angle dependence of the grating coupling efficiency to determine local…

Instrumental aberrations strongly limit high-contrast imaging of exoplanets, especially when they produce quasistatic speckles in the science images. With the help of recent advances in deep learning, we have developed in previous works an…

Instrumentation and Methods for Astrophysics · Physics 2022-11-14 Maxime Quesnel , Gilles Orban de Xivry , Olivier Absil , Gilles Louppe