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Quantitative phase microscopy (QPM), a technique combining phase imaging and microscopy, enables visualization of the 3D topography in reflective samples, as well as the inner structure or refractive index distribution of transparent and…

Optics · Physics 2025-01-17 Vicente Mico , Juanjuan Zheng , Javier Garcia , Zeev Zalevsky , Peng Gao

Paradoxically, imaging with resolution much below the wavelength $\lambda$ - now common place in the visible spectrum - remains challenging at lower frequencies, where arguably it is needed most due to the large wavelengths used. Techniques…

Optics · Physics 2023-12-12 Alessandro Tuniz , Boris T. Kuhlmey

Compressed sensing is an imaging paradigm that allows one to invert an underdetermined linear system by imposing the a priori knowledge that the sought after solution is sparse (i.e., mostly zeros). Previous works have shown that if one…

Image and Video Processing · Electrical Eng. & Systems 2023-12-05 Nicholas Dwork , Erin K. Englund

An image super-resolution method from multiple observation of low-resolution images is proposed. The method is based on sub-pixel accuracy block matching for estimating relative displacements of observed images, and sparse signal…

Computer Vision and Pattern Recognition · Computer Science 2014-02-18 Toshiyuki Kato , Hideitsu Hino , Noboru Murata

Super-resolution imaging (S.R.) is a series of techniques that enhance the resolution of an imaging system, especially in surveillance cameras where simplicity and low cost are of great importance. S.R. image reconstruction can be viewed as…

Image and Video Processing · Electrical Eng. & Systems 2020-09-22 Donya Khaledyan , Abdolah Amirany , Kian Jafari , Mohammad Hossein Moaiyeri , Abolfazl Zargari Khuzani , Najmeh Mashhadi

In this work we search for best practices in pre-processing of Electrocardiogram (ECG) signals in order to train better classifiers for the diagnosis of heart conditions. State of the art machine learning algorithms have achieved remarkable…

Signal Processing · Electrical Eng. & Systems 2025-05-16 Amir Salimi , Sunil Vasu Kalmady , Abram Hindle , Osmar Zaiane , Padma Kaul

Metasurfaces have provided a novel and promising platform for the realization of compact and large-scale optical devices. The conventional metasurface design approach assumes periodic boundary conditions for each element, which is…

We propose a polarimetric microwave imaging technique that exploits recent advances in computational imaging. We utilize a frequency-diverse cavity-backed metasurface, allowing us to demonstrate high-resolution polarimetric imaging using a…

Secondary electron (SE) imaging techniques, such as scanning electron microscopy and helium ion microscopy (HIM), use electrons emitted by a sample in response to a focused beam of charged particles incident at a grid of raster scan…

Signal Processing · Electrical Eng. & Systems 2026-03-12 Vaibhav Choudhary , Akshay Agarwal , Vivek K Goyal

Based on the concept of sub-wavelength imaging through compensated bilayer of anisotropic metamaterials (AMMs), which is an expansion of the perfect lens configuration, we propose two dimensional prism pair structures of compensated AMMs…

Optics · Physics 2009-11-13 Junming Zhao , Yijun Feng , Bo Zhu , Tian Jiang

Downsampling images and labels, often necessitated by limited resources or to expedite network training, leads to the loss of small objects and thin boundaries. This undermines the segmentation network's capacity to interpret images…

Image and Video Processing · Electrical Eng. & Systems 2024-10-27 Shahzad Ali , Yu Rim Lee , Soo Young Park , Won Young Tak , Soon Ki Jung

Compressive sensing is a technique to sample signals well below the Nyquist rate using linear measurement operators. In this paper we present an algorithm for signal reconstruction given such a set of measurements. This algorithm…

Information Theory · Computer Science 2009-06-08 Graeme Pope

Implementing electrophysiological recordings within an MRI environment is challenging due to complex interactions between recording probes and MRI-generated fields, which can affect both safety and data quality. This study aims to develop…

Metasurfaces -- ultrathin structures composed of subwavelength optical elements -- have revolutionized light manipulation by enabling precise control over electromagnetic waves' amplitude, phase, polarization, and spectral properties.…

Optics · Physics 2024-11-15 Charles Roques-Carmes , Kai Wang , Yuanmu Yang , Arka Majumdar , Zin Lin

It has always been a big challenge to identify subtle changes in Electroencephalogram (EEG) signals. Minor differences often lead to vital decisions, for example, which grade a certain tumour belong to or whether a haemorrhage can result in…

Systems and Control · Electrical Eng. & Systems 2022-06-01 Debojyoti Seth

Modal phase matching (MPM) is a widely used phase matching technique in Al$_x$Ga$_{1-x}$As and other $\chi^{(2)}$ nonlinear waveguides for efficient wavelength conversions. The use of a non-fundamental spatial mode compensates the material…

Optics · Physics 2021-12-30 Dongpeng Kang , Weiqi Zhang , Amr S. Helmy , Siyuan Yu , Liying Tan , Jing Ma

Sub-pixel registration is a crucial step for applications such as super-resolution in remote sensing, motion compensation in magnetic resonance imaging, and non-destructive testing in manufacturing, to name a few. Recently, these…

Computer Vision and Pattern Recognition · Computer Science 2017-05-02 Vildan Atalay Aydin , Hassan Foroosh

Electrical Impedance Tomography (EIT) systems are becoming popular because they present several advantages over competing systems. However, EIT leads to images with very low resolution. Moreover, the nonuniform sampling characteristic of…

Computer Vision and Pattern Recognition · Computer Science 2019-05-01 Ricardo A. Borsoi , Julio C. C. Aya , Guilherme H. Costa , José C. M. Bermudez

In this article, we provide an alternative up-sampling and PSF deconvolution method for the iterative multi-exposure coaddition. Different from the previous works, the new method has a ratio-correction term, which allows the iterations to…

Instrumentation and Methods for Astrophysics · Physics 2022-10-26 Lei Wang , Guoliang Li , Xi Kang

Multiple-input multiple-output (MIMO) array based millimeter-wave (MMW) imaging has a tangible prospect in applications of concealed weapons detection. A near-field imaging algorithm based on wavenumber domain processing is proposed for a…

Signal Processing · Electrical Eng. & Systems 2021-01-25 Shiyong Li , Shuoguang Wang , Moeness G. Amin , Guoqiang Zhao