scholarly journals Superresolution of Images Using Area Preserving Geometric Evolution Laws

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Caroline Jäger ◽  
Simon Praetorius ◽  
Axel Voigt
Keyword(s):  
Level Set ◽  
Mean Curvature ◽  
Mean Curvature Flow ◽  
Curvature Flow ◽  
Small Scale ◽  
Geometric Evolution ◽  
Flow Surface ◽  
Willmore Flow ◽  
Evolution Laws ◽  
Area Preserving

PDE-based approaches are used to obtain superresolution of images. Using level set method for area constraint geometric evolution laws allows to remove pixelation in images without removing small-scale features. We compare mean curvature flow, surface diffusion, and Willmore flow for this purpose.

Computation of geometric partial differential equations and mean curvature flow

Acta Numerica ◽  
2005 ◽  
Vol 14 ◽  
pp. 139-232 ◽  
Author(s):  
Klaus Deckelnick ◽  
Gerhard Dziuk ◽  
Charles M. Elliott
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Level Set ◽  
Phase Field ◽  
Mean Curvature ◽  
Mean Curvature Flow ◽  
Curvature Flow ◽  
Partial Differential ◽  
Geometric Partial Differential Equations ◽  
Geometric Pdes

This review concerns the computation of curvature-dependent interface motion governed by geometric partial differential equations. The canonical problem of mean curvature flow is that of finding a surface which evolves so that, at every point on the surface, the normal velocity is given by the mean curvature. In recent years the interest in geometric PDEs involving curvature has burgeoned. Examples of applications are, amongst others, the motion of grain boundaries in alloys, phase transitions and image processing. The methods of analysis, discretization and numerical analysis depend on how the surface is represented. The simplest approach is when the surface is a graph over a base domain. This is an example of a sharp interface approach which, in the general parametric approach, involves seeking a parametrization of the surface over a base surface, such as a sphere. On the other hand an interface can be represented implicitly as a level surface of a function, and this idea gives rise to the so-called level set method. Another implicit approach is the phase field method, which approximates the interface by a zero level set of a phase field satisfying a PDE depending on a new parameter. Each approach has its own advantages and disadvantages. In the article we describe the mathematical formulations of these approaches and their discretizations. Algorithms are set out for each approach, convergence results are given and are supported by computational results and numerous graphical figures. Besides mean curvature flow, the topics of anisotropy and the higher order geometric PDEs for Willmore flow and surface diffusion are covered.

The Surface Area Preserving Mean Curvature Flow in Quasi-Fuchsian Manifolds

2012 ◽  
Vol 32 (6) ◽  
pp. 2191-2202 ◽  
Author(s):  
Tian Daping ◽  
Li Guanghan ◽  
Wu Chuanxi
Keyword(s):  
Surface Area ◽  
Mean Curvature ◽  
Mean Curvature Flow ◽  
Curvature Flow ◽  
Area Preserving

scholarly journals On the horizontal mean curvature flow for axisymmetric surfaces in the Heisenberg group

2014 ◽  
Vol 16 (03) ◽  
pp. 1350027 ◽  
Author(s):  
Fausto Ferrari ◽  
Qing Liu ◽  
Juan J. Manfredi
Keyword(s):  
Heisenberg Group ◽  
Level Set Method ◽  
Level Set ◽  
Viscosity Solutions ◽  
Mean Curvature ◽  
Explicit Solution ◽  
Mean Curvature Flow ◽  
Curvature Flow ◽  
Existence And Stability ◽  
The Mean

We study the horizontal mean curvature flow in the Heisenberg group by using the level-set method. We prove the uniqueness, existence and stability of axisymmetric viscosity solutions of the level-set equation. An explicit solution is given for the motion starting from a subelliptic sphere. We also give several properties of the level-set method and the mean curvature flow in the Heisenberg group.

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