443 research outputs found
Quaternion Windowed Linear Canonical Transform of Two-Dimensional Quaternionic Signals
We investigate the 2D quaternion windowed linear canonical transform(QWLCT)
in this paper. Firstly, we propose the new definition of the QWLCT, and then
several important properties of newly defined QWLCT, such as bounded, shift,
modulation, orthogonality relation, are derived based on the spectral
representation of the quaternionic linear canonical transform(QLCT). Finally,
by the Heisenberg uncertainty principle for the QLCT and the orthogonality
relation property for the QWLCT, the Heisenberg uncertainty principle for the
QWLCT is established.Comment: This article is 14 pages lon
Uncertainty principles for the windowed offset linear canonical transform
The windowed offset linear canonical transform (WOLCT) can be identified as a
generalization of the windowed linear canonical transform (WLCT). In this
paper, we generalize several different uncertainty principles for the WOLCT,
including Heisenberg uncertainty principle, Hardy's uncertainty principle,
Beurling's uncertainty principle, Lieb's uncertainty principle, Donoho-Stark's
uncertainty principle, Amrein-Berthier-Benedicks's uncertainty principle,
Nazarov's uncertainty principle and Logarithmic uncertainty principle.Comment: 12 page
Uncertainty Principles for Quaternion Windowed Offset Linear Canonical Transform of Two Dimensional Signals
The offset linear canonical transform encompassing the numerous integral
transforms, is a promising tool for analyzing non-stationary signals with more
degrees of freedom. In this paper, we generalize the windowed offset linear
canonical transform for quaternion-valued signals, by introducing a novel
time-frequency transform namely the quaternion windowed offset linear canonical
transform of 2D quaternion-valued signals. We initiate our investigation by
studying some fundamental properties of the proposed transform including inner
product relation, energy conservation, and reproducing formula by employing the
machinery of quaternion offset linear canonical transforms. Some uncertainty
principles such as Heisenberg-Weyl, logarithmic and local uncertainty principle
are also derived for quaternion windowed offset linear canonical transform.
Finally, we gave an example of quaternion windowed offset linear canonical
transform.Comment: 16 pages. arXiv admin note: text overlap with arXiv:2006.0675
Convolution and correlation theorems for the windowed offset linear canonical transform
In this paper, some important properties of the windowed offset linear
canonical transform (WOLCT) such as shift, modulation and orthogonality
relation are introduced. Based on these properties we derive the convolution
and correlation theorems for the WOLCT.Comment: The article consists of six page
Uncertainty Principles For the continuous Gabor quaternion linear canonical transform
Gabor transform is one of the performed tools for time-frequency signal
analysis. The principal aim of this paper is to generalize the Gabor Fourier
transform to the quaternion linear canonical transform. Actually, this
transform gives us more flexibility to studied nonstationary and local signals
associated with the quaternion linear canonical transform. Some useful
properties are derived, such as Plancherel and inversion formulas. And we prove
some uncertainty principles: those including Heisenberg's, Lieb's and
logarithmic inequalities. We finish by analogs of concentration and Benedick's
type theorems
Short time quaternion quadratic phase Fourier transform and its uncertainty principles
In this paper, we extend the quadratic phase Fourier transform of a complex
valued functions to that of the quaternion valued functions of two variables.
We call it the quaternion quadratic phase Fourier transform (QQPFT). Based on
the relation between the QQPFT and the quaternion Fourier transform (QFT) we
obtain the sharp Hausdorff-Young inequality for QQPFT. We define the short time
quaternion quadratic phase Fourier transform (STQQPFT) and explore some of its
properties including inner product relation and inversion formula. We find its
relation with that of the 2D quaternion ambiguity function and the quaternion
Wigner-Ville distribution associated with QQPFT and obtain the Lieb's
uncertainty and entropy uncertainty principles for these three transforms
Uncertainty principles for the windowed Hankel transform
The aim of this paper is to prove some new uncertainty principles for the
windowed Hankel transform. They include uncertainty principle for orthonormal
sequence, local uncertainty principle, logarithmic uncertainty principle and
Heisenberg-type uncertainty principle. As a side result, we obtain the
Shapiro's dispersion theorem for the windowed Hankel transform.Comment: 15 page
Uncertainty principles for the short-time linear canonical transform of complex signals
The short-time linear canonical transform (STLCT) can be identified as a
generalization of the short-time Fourier transform (STFT). It is a novel
time-frequency analysis tool. In this paper, we generalize some different
uncertainty principles for the STLCT of complex signals. Firstly, one
uncertainty principle for the STLCT of complex signals in time and frequency
domains is derived. Secondly, the uncertainty principle for the STLCT of
complex signals in two STLCT domains is obtained. Finally, the uncertainty
principle for the two conditional standard deviations of the spectrogram
associated with the STLCT is discussed.Comment: 10 page
Quaternion Linear Canonical Wavelet Transform and The Corresponding Uncertainty Inequalities
The linear canonical wavelet transform has been shown to be a valuable and
powerful time-frequency analyzing tool for optics and signal processing. In
this article, we propose a novel transform called quaternion linear canonical
wavelet transform which is designed to represent two dimensional
quaternion-valued signals at different scales, locations and orientations. The
proposed transform not only inherits the features of quaternion wavelet
transform but also has the capability of signal representation in quaternion
linear canonical domain. We investigate the fundamental properties of
quaternion linear canonical wavelet transform including Parseval's formula,
energy conservation, inversion formula, and characterization of its range using
the machinery of quaternion linear canonical transform and its convolution. We
conclude our investigation by deriving an analogue of the classical
Heisenberg-Pauli-Weyl uncertainty inequality and the associated logarithmic and
local versions for the quaternion linear canonical wavelet transform.Comment: 20 page
Local uncertainty principles for the two-sided Gabor quaternion Fourier transform
By the important applications of Gabor transform in time-frequency analysis
and signal analysis, in this paper, we consider the Gabor quaternion Fourier
transform (GQFT), and we prove of it a version Benedicks-type uncertainty
principle for GQFT and some local concentration uncertainty principles
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