Results 321 to 330 of about 521,797 (371)

Discrete and finite fractional Fourier transforms

Frontiers in Optics, 2003
Finite models for oscillator or waveguide systems provide corresponding fractional Fourier-type transforms between finite arrays of ‘sensor’ points. The kernel matrices are unitary and are well-known in group theory; they involve the discrete polynomials of Kravchuk, q-Kravchuk, Meixner and Hahn.
openaire   +1 more source

Fractional-Fourier-transform calculation through the fast-Fourier-transform algorithm

Applied Optics, 1996
A method for the calculation of the fractional Fourier transform (FRT) by means of the fast Fourier transform (FFT) algorithm is presented. The process involves mainly two FFT's in cascade; thus the process has the same complexity as this algorithm. The method is valid for fractional orders varying from -1 to 1.
J, García, D, Mas, R G, Dorsch
openaire   +2 more sources

Detection of R-peaks using fractional Fourier transform and principal component analysis

Journal of Ambient Intelligence and Humanized Computing, 2021
Varun Gupta, M. Mittal, Vikas Mittal, Y. Chaturvedi   +3 more
semanticscholar   +1 more source

Fractional Integrals of Fractional Fourier Transform for Integrable Boehmians

Proceedings of the National Academy of Sciences, India Section A: Physical Sciences, 2017
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Singh, Abhishek, Banerji, P. K.
openaire   +1 more source

Fractional order Fourier transform and Fourier optics

Optics Communications, 1994
Abstract The electromagnetic field transfer from a spherical emitter to a spherical receiver is expressed through a fractional order Fourier transform. Given an emitter and a receiver, the order of the fractional transform is calculated as a function of their distance and their radii of curvature.
Pierre Pellat-Finet, Georges Bonnet
openaire   +1 more source

Parameter diagrams for the fractional Fourier transform

Journal of Modern Optics, 2001
Abstract A simple diagram illustrates the relations between six parameters of the generalized FRT. The diagram is developed to illustrate a variety of equations which have appeared in the literature, particularly in relation to free-space propagation, Gaussian beams, optical filtering experiments, and the ABCD matrix.
openaire   +1 more source

From Complex Fractional Fourier Transform to Complex Fractional Radon Transform

Communications in Theoretical Physics, 2004
Summary: We show that for \(n\)-dimensional complex fractional Fourier transform the corresponding complex fractional Radon transform can also be derived, however, it is different from the direct product of two \(n\)-dimensional real fractional Radon transforms. The complex fractional Radon transform of two-mode Wigner operator is calculated.
Fan, Hong-Yi, Jiang, Nian-Quan
openaire   +1 more source

Multiple color image fusion, compression, and encryption using compressive sensing, chaotic-biometric keys, and optical fractional Fourier transform

Optics & Laser Technology, 2022
M. Abuturab, A. Alfalou
semanticscholar   +1 more source

Fractional Fourier transform: Time-frequency representation and structural instantaneous frequency identification

Mechanical systems and signal processing, 2022
Lian-Wei Lu, W. Ren, Shi-Dong Wang
semanticscholar   +1 more source

Double-encrypted watermarking algorithm based on cosine transform and fractional Fourier transform in invariant wavelet domain

Information Sciences, 2021
Yuanmin Li, Deyun Wei, Lina Zhang
semanticscholar   +1 more source