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We present an alternative numerical reconstruction algorithm for direct tomographic reconstruction of a sample refractive indices from the measured intensities of its far-field coherent diffraction patterns. We formulate the well-known…

Computational Physics · Physics 2019-02-06 T. Ramos , Bastian E. Grønager , Martin Skovgaard Andersen , J. W. Andreasen

We propose to use transformation optics to generate a general illusion such that an arbitrary object appears to be like some other object of our choice. This is achieved by using a remote device that transforms the scattered light outside a…

This paper is a review of recent mathematical and computational advances in optical tomography. We discuss the physical foundations of forward models for light propagation on microscopic, mesoscopic and macroscopic scales. We also consider…

Analysis of PDEs · Mathematics 2009-07-16 Simon Arridge , John Schotland

We propose a method to reconstruct the optical properties of a scattering medium with subwavelength resolution. The method is based on the solution to the inverse scattering problem with photoactivated internal sources. Numerical…

Optics · Physics 2018-08-01 Anna C. Gilbert , Howard W. Levinson , John C. Schotland

We discover long-lived (microsecond-scale) optical waveguiding in the wake of atmospheric laser filaments. We also observe the formation and then outward propagation of the consequent sound wave. These effects may be used for remote…

Light from astronomical objects must travel through the earth's turbulent atmosphere before it can be imaged by ground-based telescopes. To enable direct imaging at maximum theoretical angular resolution, advanced techniques such as those…

Speckle Imaging based on triple correlation is a very efficient image reconstruction technique which is used to retrieve Fourier phase information of the object in presence of atmospheric turbulence. We have developed both Direct Bispectrum…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha

We present an indirect imaging method that measures both amplitude and phase information from a transmissive target. Our method is based on an optical eigenmode decomposition of the light intensity and the first-order cross correlation…

In this paper, we study the problem of reproducing the world lighting from a single image of an object covered with random specular microfacets on the surface. We show that such reflectors can be interpreted as a randomized mapping from the…

Computer Vision and Pattern Recognition · Computer Science 2014-12-30 Zhengdong Zhang , Phillip Isola , Edward H. Adelson

Coherent diffraction imaging methods enable imaging beyond lens-imposed resolution limits. In these methods, the object can be recovered by minimizing an error metric that quantifies the difference between diffraction patterns as observed,…

Image and Video Processing · Electrical Eng. & Systems 2019-07-24 Saugat Kandel , S. Maddali , Marc Allain , Stephan O. Hruszkewycz , Chris Jacobsen , Youssef S G Nashed

Three dimensional images having continuous horizontal parallax were developed by wavelength enconding of view followed by a natural decoding process of projection onto a diffractive screen. It allows for the direct criation of "holoimages"…

Optics · Physics 2007-05-23 J. J. Lunazzi

The dewetting of an azopolymer droplet, followed by the photostructuration of the evaporated droplet, is employed to create an amplitude mask. This straightforward process yields a large area featuring periodic micro- and nanostructures.…

Optics · Physics 2024-02-08 R. Barille , A. Korbut , S. Zielinska , E. Ortyl , D. G. Perez

We present a technique for dense 3D reconstruction of objects using an imaging sonar, also known as forward-looking sonar (FLS). Compared to previous methods that model the scene geometry as point clouds or volumetric grids, we represent…

Computer Vision and Pattern Recognition · Computer Science 2022-09-20 Mohamad Qadri , Michael Kaess , Ioannis Gkioulekas

Image retargeting, which resizes images to one with a prescribed aspect ratio by determining an optimal warping map, has gained substantial interest in imaging science. Despite significant advances, existing methods often fail to ensure…

Numerical Analysis · Mathematics 2025-10-16 Chengyang Liu , Michael K. Ng

We study the direct and an inverse source problem for the radiative transfer equation arising in optical molecular imaging. We show that for generic absorption and scattering coefficients, the direct problem is well-posed and the inverse…

Analysis of PDEs · Mathematics 2008-03-31 Plamen Stefanov , Gunther Uhlmann

When taking images against strong light sources, the resulting images often contain heterogeneous flare artifacts. These artifacts can importantly affect image visual quality and downstream computer vision tasks. While collecting real data…

Image and Video Processing · Electrical Eng. & Systems 2023-09-01 Yuyan Zhou , Dong Liang , Songcan Chen , Sheng-Jun Huang , Shuo Yang , Chongyi Li

We analyze the performance of a planar lens based on realistic negative index material in a generalized geometry. We demonstrate that the conventional superlens design (where the lens is centered between the object and the image) is not…

Optics · Physics 2016-09-08 Viktor A. Podolskiy , Nicholas A. Kuhta , Graeme W. Milton

Nonlinear lens distortion rectification is a common first step in image processing applications where the assumption of a linear camera model is essential. For rectifying the lens distortion, forward distortion model needs to be known.…

Computer Vision and Pattern Recognition · Computer Science 2017-07-05 Burak Benligiray , Cihan Topal

We study the inverse problem of locating point sources from far-field data under plane wave incidence. A direct computational method is developed based on multiple scattering theory, using a novel indicator function to avoid iterative…

Analysis of PDEs · Mathematics 2025-09-18 Nana Meng

The development of compact indirect microwave holographic set-up by the implementation of low cost, specifically designed directive antennae as transmitter and receiver is proposed. Microwave holograms are recorded by 2D scanning over a…

Image and Video Processing · Electrical Eng. & Systems 2020-02-26 Vineeta Kumari , Aijaz Ahmed , Gyanendra Sheoran , Tirupathiraju Kanumuri , Chandra shakher
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