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In this paper, we introduce a new (constructive) characterization of tight wavelet frames on non-flat domains in both continuum setting, i.e. on manifolds, and discrete setting, i.e. on graphs; discuss how fast tight wavelet frame…

Functional Analysis · Mathematics 2015-10-07 Bin Dong

Future Extremely Large Telescopes will adopt segmented primary mirrors with several hundreds of segments. Cophasing of the segments together is essential to reach high wavefront quality. The phasing sensor must be able to maintain very high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Arthur Vigan , Kjetil Dohlen , Silvio Mazzanti

Wavefront shaping systems aim to image deep into scattering tissue by reshaping incoming and outgoing light to correct aberrations caused by tissue inhomogeneity However, the desired modulation depends on the unknown tissue structure and…

Optics · Physics 2026-01-14 Sagi Monin , Marina Alterman , Anat Levin

Zernike's phase contrast microscopy (PCM) is among the most widely used techniques for observing phase objects, but it lacks quantitative nature, as it cannot directly provide phase information. Current methods for computationally…

We show that customized optical patterns can be generated by employing feedback-based wavefront shaping without prior knowledge of the transmission matrix of optical systems. To control the spatial distribution of intensity within the…

Optics · Physics 2018-12-04 Peilong Hong

We propose a method to reconstruct sparse signals degraded by a nonlinear distortion and acquired at a limited sampling rate. Our method formulates the reconstruction problem as a nonconvex minimization of the sum of a data fitting term and…

Optimization and Control · Mathematics 2023-01-19 Arthur Marmin , Marc Castella , Jean-Christophe Pesquet , Laurent Duval

Compressed sensing has empowered quality image reconstruction with fewer data samples than previously though possible. These techniques rely on a sparsifying linear transformation. The Daubechies wavelet transform is a common sparsifying…

Image and Video Processing · Electrical Eng. & Systems 2021-06-17 Nicholas Dwork , Daniel O'Connor , Corey A. Baron , Ethan M. I. Johnson , Adam B. Kerr , John M. Pauly , Peder E. Z. Larson

We present a new approach for image reconstruction and weak lensing measurements with interferometers. Based on the shapelet formalism presented in Refregier (2001), object images are decomposed into orthonormal Hermite basis functions. The…

Astrophysics · Physics 2009-11-06 Tzu-Ching Chang , Alexandre Refregier

The phase retrieval from multi-frequency intensity (power) observations is considered. The object to be reconstructed is complex-valued. A novel algorithm is presented that accomplishes both the object phase (absolute phase) retrieval and…

Signal Processing · Electrical Eng. & Systems 2018-02-07 Vladimir Katkovnik , Karen Egiazarian

Diffraction limit is manifested in the loss of high spatial frequency information that results from decay of evanescent waves. As a result, conventional far-field optics yields no information about an object's subwavelength features. Here…

Optics · Physics 2012-01-24 Leonid Alekseyev , Evgenii Narimanov , Jacob Khurgin

We present Rewis3d, a framework that leverages recent advances in feed-forward 3D reconstruction to significantly improve weakly supervised semantic segmentation on 2D images. Obtaining dense, pixel-level annotations remains a costly…

Computer Vision and Pattern Recognition · Computer Science 2026-03-09 Jonas Ernst , Wolfgang Boettcher , Lukas Hoyer , Jan Eric Lenssen , Bernt Schiele

This paper proposes an image interpolation algorithm exploiting sparse representation for natural images. It involves three main steps: (a) obtaining an initial estimate of the high resolution image using linear methods like FIR filtering,…

Computer Vision and Pattern Recognition · Computer Science 2013-08-07 H. Lakshman , W. -Q Lim , H. Schwarz , D. Marpe , G. Kutyniok , T. Wiegand

The Hessian matrix plays an important role in correct interpretation of the multiple scattered wave fields inside the FWI frame work. Due to the high computational costs, the computation of the Hessian matrix is not feasible. Consequently,…

Geophysics · Physics 2022-04-21 S. M. Aydin Shoja , Giovanni A. Meles , Kees Wapenaar

We consider the imaging problem of the reconstruction of a three-dimensional object via optical diffraction tomography under the assumptions of the Born approximation. Our focus lies in the situation that a rigid object performs an…

Numerical Analysis · Mathematics 2024-07-11 Robert Beinert , Michael Quellmalz

Phase retrieval aims at reconstructing unknown signals from magnitude measurements of linear mixtures. In this paper, we consider the phase retrieval with dictionary learning problem, which includes an additional prior information that the…

Signal Processing · Electrical Eng. & Systems 2023-01-24 Tianyi Liu , Andreas M. Tillmann , Yang Yang , Yonina C. Eldar , Marius Pesavento

We implement an efficient method of computation of two dimensional Fourier-type integrals based on approximation of the integrand by Gaussian radial basis functions, which constitute a standard tool in approximation theory. As a result, we…

Numerical Analysis · Mathematics 2022-02-07 A. Martinez-Finkelshtein , D. Ramos-Lopez , D. R. Iskander

A compressive sensing (CS) reconstruction method for polynomial phase signals is proposed in this paper. It relies on the Polynomial Fourier transform, which is used to establish a relationship between the observation and sparsity domain.…

Information Theory · Computer Science 2016-11-15 Srdjan Stankovic , Irena Orovic , Ljubisa Stankovic

We propose a system for visual scene analysis and recognition based on encoding the sparse, latent feature-representation of an image into a high-dimensional vector that is subsequently factorized to parse scene content. The sparse feature…

Computer Vision and Pattern Recognition · Computer Science 2024-07-01 Christopher J. Kymn , Sonia Mazelet , Annabel Ng , Denis Kleyko , Bruno A. Olshausen

In this paper we characterize and construct novel oversampled filter banks implementing fusion frames. A fusion frame is a sequence of orthogonal projection operators whose sum can be inverted in a numerically stable way. When properly…

Information Theory · Computer Science 2015-10-28 Amina Chebira , Matthew Fickus , Dustin G. Mixon

A common task in inverse problems and imaging is finding a solution that is sparse, in the sense that most of its components vanish. In the framework of compressed sensing, general results guaranteeing exact recovery have been proven. In…

Numerical Analysis · Mathematics 2021-04-29 Monica Pragliola , Daniela Calvetti , Erkki Somersalo
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