English
Related papers

Related papers: A Factorized Variational Technique for Phase Unwra…

200 papers

We consider the phase retrieval problem for signals that belong to a union of subspaces. We assume that amplitude measurements of the signal of length $n$ are observed after passing it through a random $m \times n$ measurement matrix. We…

Information Theory · Computer Science 2018-07-18 M. Salman Asif , Chinmay Hegde

From 1971 to 2012 dual-wavelength optical-metrology used only the demodulated low-sensitivity phase-difference of two close-sensitive fringes. Dual-wavelength phase-metrology that additionally uses the phase-sum was first reported by Di et…

Instrumentation and Detectors · Physics 2018-04-04 Manuel Servin , Moises Padilla , Guillermo Garnica

We present a simple, frequency domain, preprocessing step to Kirchhoff migration that allows the method to image scatterers when the wave field phase information is lost at the receivers, and only intensities are measured. The resulting…

Numerical Analysis · Mathematics 2016-09-21 Patrick Bardsley , Fernando Guevara Vasquez

A method for exploring photon-number entangled states with weak nonlinearities is described. We show that it is possible to create and detect such entanglement at various scales, ranging from microscopic to macroscopic systems. In the…

Quantum Physics · Physics 2015-10-28 Yingqiu He , Dong Ding , Fengli Yan , Ting Gao

In coherent X-ray diffraction microscopy the diffraction pattern generated by a sample illuminated with coherent x-rays is recorded, and a computer algorithm recovers the unmeasured phases to synthesize an image. By avoiding the use of a…

We tackle the problem of automatic calibration of radially distorted cameras in challenging conditions. Accurately determining distortion parameters typically requires either 1) solving the full Structure from Motion (SfM) problem involving…

Computer Vision and Pattern Recognition · Computer Science 2025-09-16 Daniil Sinitsyn , Linus Härenstam-Nielsen , Daniel Cremers

Spectral unmixing (SU) is a technique to characterize mixed pixels in hyperspectral images measured by remote sensors. Most of the spectral unmixing algorithms are developed using the linear mixing models. To estimate endmembers and…

Computer Vision and Pattern Recognition · Computer Science 2019-02-21 Sara Khoshsokhan , Roozbeh Rajabi , Hadi Zayyani

This paper presents a new Bayesian model and algorithm for nonlinear unmixing of hyperspectral images. The model proposed represents the pixel reflectances as linear combinations of the endmembers, corrupted by nonlinear (with respect to…

Methodology · Statistics 2015-10-06 Yoann Altmann , Marcelo Pereyra , Stephen McLaughlin

We consider an error model for phased array with gain errors and phase errors, with errors dependent on the phase applied and the antenna index. Under this model, we propose an algorithm for measuring the errors by selectively turning on…

Signal Processing · Electrical Eng. & Systems 2021-07-21 Joyson Sebastian , Pranav Dayal , Kee-Bong Song , Walid AliAhmad

For the first time, this paper investigates the phase retrieval problem with the assumption that the phase (of the complex signal) is sparse in contrast to the sparsity assumption on the signal itself as considered in the literature of…

Optimization and Control · Mathematics 2019-01-29 Hieu Thao Nguyen , D. Russell Luke , Oleg Soloviev , Michel Verhaegen

We consider the geometry associated to the ambiguities of the one-dimensional Fourier phase retrieval problem for vectors in ${\mathbb C}^{N+1}$. Our first result states that the space of signals has a finite covering (which we call the…

Functional Analysis · Mathematics 2019-09-24 Dan Edidin

X-ray ptychography is one of the versatile techniques for nanometer resolution imaging. The magnitude of the diffraction patterns is recorded on a detector and the phase of the diffraction patterns is estimated using phase retrieval…

Image and Video Processing · Electrical Eng. & Systems 2021-05-21 Prasan Shedligeri , Florian Schiffers , Semih Barutcu , Pablo Ruiz , Aggelos K Katsaggelos , Oliver Cossairt

Markov chain Monte Carlo (MCMC) algorithms are simple and extremely powerful techniques to sample from almost arbitrary distributions. The flaw in practice is that it can take a large and/or unknown amount of time to converge to the…

Machine Learning · Computer Science 2014-11-13 Xianghang Liu , Justin Domke

Reconstructing a signal from squared linear (rank-one quadratic) measurements is a challenging problem with important applications in optics and imaging, where it is known as phase retrieval. This paper proposes two new phase retrieval…

Information Theory · Computer Science 2016-09-21 Cheng Qian , Nicholas D. Sidiropoulos , Kejun Huang , Lei Huang , H. C. So

Structured light 3D surface imaging is a school of techniques in which structured light patterns are used for measuring the depth map of the object. Among all the designed structured light patterns, phase pattern has become most popular…

Image and Video Processing · Electrical Eng. & Systems 2020-09-14 Zhenzhou Wang

This paper is concerned with the problem of recovering a structured signal from a relatively small number of corrupted random measurements. Sharp phase transitions have been numerically observed in practice when different convex programming…

Information Theory · Computer Science 2021-01-05 Zhongxing Sun , Wei Cui , Yulong Liu

One of the primary sources of suboptimal image quality in ultrasound imaging is phase aberration. It is caused by spatial changes in sound speed over a heterogeneous medium, which disturbs the transmitted waves and prevents coherent…

Image and Video Processing · Electrical Eng. & Systems 2024-07-03 Mostafa Sharifzadeh , Sobhan Goudarzi , An Tang , Habib Benali , Hassan Rivaz

A polarimetric synthetic aperture radar (PolSAR) system, which uses multiple images acquired with different polarizations in both transmission and reception, has the potential to improve the description and interpretation of the observed…

Signal Processing · Electrical Eng. & Systems 2025-07-08 Dehbia Hanis , Luca Pallotta , Augusto Aubry , Aichouche Belhadj-Aissa , Antonio De Maio

The visualization of pure phase objects by wavefront sensing has important applications ranging from surface profiling to biomedical microscopy, and generally requires bulky and complicated setups involving optical spatial filtering,…

Optics · Physics 2023-08-29 Jianing Liu , Hao Wang , Yuyu Li , Lei Tian , Roberto Paiella

A phase shift and sum (PSAS) algorithm to image objects in dispersive media is presented. The algorithm compensates the phase shift of the scattered field from the receiver to the source for each frequency component in an ultrawideband…

Signal Processing · Electrical Eng. & Systems 2019-08-28 Wenyi Shao