Gray image thresholding based on three-dimensional Renyi entropy

Recently, Savaré-Toscani proved that the Rényi entropy power of general probability densities solving the p-nonlinear heat equation in Rn is a concave function of time under certain conditions of three parameters n,p,μ, which extends Costa’s concavity inequality for Shannon’s entropy power to the Rényi entropy power. In this paper, we give a condition Φ(n,p,μ) of n,p,μ under which the concavity of the Rényi entropy power is valid. The condition Φ(n,p,μ) contains Savaré-Toscani’s condition as a special case and much more cases. Precisely, the points (n,p,μ) satisfying Savaré-Toscani’s condition consist of a two-dimensional subset of R3, and the points satisfying the condition Φ(n,p,μ) consist a three-dimensional subset of R3. Furthermore, Φ(n,p,μ) gives the necessary and sufficient condition in a certain sense. Finally, the conditions are obtained with a systematic approach.

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Cortical Entropy Values Correlate with Brain Scale-Free Dynamics

10.1101/147405 ◽

2017 ◽

Author(s):

Arturo Tozzi ◽

James F. Peters ◽

Mehmet Niyazi Çankaya

Keyword(s):

Brain Activity ◽

Brain Area ◽

Three Dimensional ◽

Renyi Entropy ◽

Rényi Entropy ◽

Two Dimensional ◽

Informational Entropy ◽

Scale Free ◽

Dimensional Object ◽

Available Information

ABSTRACTA two-dimensional shadow may encompass more information than its corresponding three-dimensional object. If we rotate the object, we achieve a pool of observed shadows from different angulations, gradients, shapes and variable length contours that make it possible for us to increase our available information. Starting from this simple observation, we show how informational entropies might turn out to be useful in the evaluation of scale-free dynamics in the brain. Indeed, brain activity exhibits a scale-free distribution, which appears as a straight line when plotted in a log power versus log frequency plot. A variation in the scale-free exponent and in the line scaling slope may occur during different functional neurophysiological states. Here we show that modifications in scaling slope are associated with variations in Rényi entropy, a generalization of Shannon informational entropy. From a three-dimensional object’s perspective, by changing its orientation (standing for the cortical scale-free exponent), we detect different two-dimensional shadows from different perception angles (standing for Rènyi entropy in different brain areas). We perform simulations showing how, starting from known values of Rènyi entropy (easily detectable in brain fMRIs or EEG traces), it is feasible to calculate the scaling slope in a given moment and a given brain area. Because changes in scale-free cortical dynamics modify brain activity, suggests the possibility of novel insights in mind reading and description of the forces required for transcranial stimulation.

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Textured Renyi Entropy for Image Thresholding

2008 Fifth International Conference on Computer Graphics, Imaging and Visualisation ◽

10.1109/cgiv.2008.48 ◽

2008 ◽

Cited By ~ 1

Author(s):

Ahmad Adel Abu Shareha ◽

Mandava Rajeswari ◽

Dhanesh Ramachandram

Keyword(s):

Renyi Entropy ◽

Rényi Entropy ◽

Image Thresholding

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Excited state Rényi entropy and subsystem distance in two-dimensional non-compact bosonic theory. Part I. Single-particle states

Journal of High Energy Physics ◽

10.1007/jhep12(2020)160 ◽

2020 ◽

Vol 2020 (12) ◽

Author(s):

Jiaju Zhang ◽

M.A. Rajabpour

Keyword(s):

Excited States ◽

Single Particle ◽

Renyi Entropy ◽

Rényi Entropy ◽

Large Momentum ◽

Particle State ◽

Two Dimensional ◽

Universal Form ◽

Conformal Field ◽

Harmonic Chain

Abstract We investigate the Rényi entropy of the excited states produced by the current and its derivatives in the two-dimensional free massless non-compact bosonic theory, which is a two-dimensional conformal field theory. We also study the subsystem Schatten distance between these states. The two-dimensional free massless non-compact bosonic theory is the continuum limit of the finite periodic gapless harmonic chains with the local interactions. We identify the excited states produced by current and its derivatives in the massless bosonic theory as the single-particle excited states in the gapless harmonic chain. We calculate analytically the second Rényi entropy and the second Schatten distance in the massless bosonic theory. We then use the wave functions of the excited states and calculate the second Rényi entropy and the second Schatten distance in the gapless limit of the harmonic chain, which match perfectly with the analytical results in the massless bosonic theory. We verify that in the large momentum limit the single-particle state Rényi entropy takes a universal form. We also show that in the limit of large momenta and large momentum difference the subsystem Schatten distance takes a universal form but it is replaced by a new corrected form when the momentum difference is small. Finally we also comment on the mutual Rényi entropy of two disjoint intervals in the excited states of the two-dimensional free non-compact bosonic theory.

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