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The first part of the paper is devoted to diffraction phenomena that can be expressed by fractional Fourier transforms whose orders are real numbers. According to a scalar theory, diffraction acts on the amplitude of the electric field as…

Optics · Physics 2022-03-17 Pierre Pellat-Finet , Éric Fogret

We propose a novel framework for finding correspondences in images based on a deep neural network that, given two images and a query point in one of them, finds its correspondence in the other. By doing so, one has the option to query only…

Computer Vision and Pattern Recognition · Computer Science 2021-08-18 Wei Jiang , Eduard Trulls , Jan Hosang , Andrea Tagliasacchi , Kwang Moo Yi

We propose a novel Neural Radiance Field (NeRF) representation for non-opaque scenes that enables fast inference by utilizing textured polygons. Despite the high-quality novel view rendering that NeRF provides, a critical limitation is that…

Graphics · Computer Science 2024-07-11 Gopal Sharma , Daniel Rebain , Kwang Moo Yi , Andrea Tagliasacchi

The second part of the article is devoted to field transfers by diffraction that are represented by fractional Fourier transformations whose orders are complex numbers. The corresponding effects on the Wigner distributions associated with…

Optics · Physics 2022-03-29 Pierre Pellat-Finet , Éric Fogret

The two-dimensional Radon transform of the Wigner quasiprobability is introduced in canonical form and the functions playing a role in its inversion are discussed. The transformation properties of this Radon transform with respect to…

Quantum Physics · Physics 2016-06-29 Alfred Wünsche

Using projections on the (generalized) eigenvectors associated to matrices that characterize the topological structure, several authors have constructed generalizations of the Fourier transform on graphs. By exploring mappings of the…

Data Analysis, Statistics and Probability · Physics 2016-05-11 R. Vilela Mendes , Hugo C. Mendes , Tanya Araújo

Within the expansive domain of optical sciences, achieving the precise characterization of light beams stands as a fundamental pursuit, pivotal for various applications, including telecommunications and imaging technologies. This study…

We present a novel strategy to automatically reconstruct 3D faces from monocular images with explicitly disentangled facial geometry (pose, identity and expression), reflectance (diffuse and specular albedo), and self-shadows. The scene…

Computer Vision and Pattern Recognition · Computer Science 2019-10-14 Abdallah Dib , Gaurav Bharaj , Junghyun Ahn , Cedric Thebault , Philippe-Henri Gosselin , Louis Chevallier

Undulator radiation from synchrotron light sources must be transported down a beamline from the source to the sample. A partially coherent photon beam may be represented in phase space using a Wigner function, and its transport may use some…

Accelerator Physics · Physics 2021-01-26 Boaz Nash , Nicholas Goldring , Jonathan Edelen , Stephen Webb , Rafael Celestre

A technique is presented for producing synthetic images from numerical simulations whereby the image resolution is adapted around prominent features. In so doing, adaptive image ray-tracing (AIR) improves the efficiency of a calculation by…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 E. R. Parkin

A new approach is proposed for reconstruction of images from Radon projections. Based on Fourier expansions in orthogonal polynomials of two and three variables, instead of Fourier transforms, the approach provides a new algorithm for the…

Classical Analysis and ODEs · Mathematics 2007-05-23 Yuan Xu

Metalenses are composed of nanostructures for focusing light and have been widely explored in many exciting applications. However, their expanding dimensions pose simulation challenges. We propose a method to simulate metalenses in a timely…

The process of transforming a raster image into a vector representation is known as image tracing. This study looks into several processing methods that include high-pass filtering, autoencoding, and vectorization to extract an abstract…

Computer Vision and Pattern Recognition · Computer Science 2023-06-16 Zineddine Bettouche , Andreas Fischer

We use Hamiltonian ray tracing and phase-space representation to describe the propagation of a single spatial soliton and soliton collisions in a Kerr nonlinear medium. Hamiltonian ray tracing is applied using the iterative nonlinear beam…

Optics · Physics 2014-03-05 Hanhong Gao , Lei Tian , George Barbastathis

We propose a methodology to design Wigner representations in phase spaces with nontrivial topology having evolution equations with desired mathematical properties. As an illustration, two representations of molecular rotations are developed…

Quantum Physics · Physics 2015-08-20 Dmitry V. Zhdanov , Tamar Seideman

We reconstruct the polarization sector of a bright polarization squeezed beam starting from a complete set of Stokes measurements. Given the symmetry that underlies the polarization structure of quantum fields, we use the unique SU(2)…

In many computer vision domains, the input images must conform with the pinhole camera model, where straight lines in the real world are projected as straight lines in the image. Performing computer vision tasks on live sports broadcast…

Computer Vision and Pattern Recognition · Computer Science 2021-12-16 Igor Janos , Wanda Benesova

The Fourier inversion of phased coherent diffraction patterns offers images without the resolution and depth-of-focus limitations of lens-based tomographic systems. We report on our recent experimental images inverted using recent…

We propose an efficient radiance field rendering algorithm that incorporates a rasterization process on adaptive sparse voxels without neural networks or 3D Gaussians. There are two key contributions coupled with the proposed system. The…

Computer Vision and Pattern Recognition · Computer Science 2025-03-18 Cheng Sun , Jaesung Choe , Charles Loop , Wei-Chiu Ma , Yu-Chiang Frank Wang

Calculations of the Fourier transform of a constant quantity over an area or volume defined by polygons (connected vertices) are often useful in modeling wave scattering, or in fourier-space filtering of real-space vector-based volumes and…

Numerical Analysis · Mathematics 2021-04-20 Brian B. Maranville