For strongly directed anisotropic processes such as coherence-enhancing di usion ltering it is crucial to use numerical schemes with highly accurate directional behavior. We show that this is not possible in a satisfactory way when discretizations are limited to 3 3 stencils. As a consequence, we investigate a novel algorithm based on 5 5 stencils. It utilizes recently discovered di erentiation...

Wherever anisotropic behaviour in physical measurements or models is encountered matrices provide adequate means to describe this anisotropy. Prominent examples are the di usion tensor magnetic resonance imaging in medical imaging or the stress tensor in civil engineering. As most measured data these matrix-valued data are also polluted by noise and require restoration. The restoration of scala...

This work introduces a generalised hybridisation strategy which utilises the information sharing mechanism deployed in Stochastic Di usion Search when applied to a number of population-based algorithms, e ectively merging this nature-inspired algorithm with some population-based algorithms. The results reported herein demonstrate that the hybrid algorithm, exploiting information-sharing within ...

We derive a cell-centered 3-D di usion di erencing scheme for arbitrary hexahedral meshes using the local support-operators method. Our method is said to be local because it yields a sparse matrix representation for the di usion equation, whereas the traditional support-operators method yields a dense matrix representation. The di usion discretization scheme that we have developed o ers several...

We compare two load balancing techniques for Cayley graphs based on information and load exchange between neighboring vertices. In the rst scheme, called natural di usion, each vertex gives (or receives) a xed part of the load di erence to (from) its direct neighbors. In the second scheme, called Cayley di usion, each vertex successively gives (or receives) a part of the load di erence to (or f...

ÐBoth experimental and simulation results have indicated the deviation from Arrhenius law of the di€usion coecient of hydrogen in metallic glasses. This deviation was traditionally explained by the existence of various kinds of jumps or in terms of continuous distributions of activation energies due to di€erent kinds of disorder. A new model is suggested, which relates this deviation to the te...

One of the central problems in stereo matching (and other image registration tasks) is the selection of optimal window sizes for comparing image regions. This paper addresses this problem with some novel algorithms based on iteratively di using support at di erent disparity hypotheses, and locally controlling the amount of di usion based on the current quality of the disparity estimate. It also...

In this note we reconsider the continuous time limit of the GARCH(1, 1) process. Let > k and p2 k denote, respectively, the cumulative returns and the volatility processes. We consider the continuous time approximation of the couple (> k , p2 k ). We show that, by choosing di!erent parameterizations, as a function of the discrete interval h, we can obtain either a degenerate or a non-degenerate...

Scale-space representation has been extensively studied in the computer vision community for analyzing image structures at di erent scales. This paper borrows and develops useful mathematical tools from scale-space theory to facilitate the task of image compression. Instead of compressing the original image directly, we propose to compress its scale-space representation obtained by the forward ...