The geometrical description of an object can be separated into two parts: a) the registration information and b) the ‘shape’ (which is invariant under registration transformation). A common choice of registration is the group of Euclidean similarity transformations, and then the geometrical properties that are invariant under this group of transformations are known as ‘similarity shape’. In thi...

The key features leading to low-energy grain boundaries in metals are discussed by reference to computersimulated structures and geometrical analysis in terms of atom packing. Low energy is found to be associated with boundary structures consisting of relatively dense packing, and this can in turn be expressed in terms of the space-filling packing of coordination polyhedra. The geometrical meth...

The Dirac equation is expressed entirely in terms of geometrical quantities by providing a geometrical interpretation for the (−1) which appears explicitly in the Dirac equation. In the modification of the Dirac electron theory which ensues, the (−1) appears as the generator of rotations in the spacelike plane orthogonal to the plane containing the electron current and spin vectors. This amount...

The purpose of non-rigid motion in computer vision is the study of the geometrical deformation that may aaect an object during its temporal evolution. One often assumes that this process is local and continuous; it is therefore the case for local geometrical features, which are considered as relevant for studying deformation. This assumption is no more valid when the structure is widely distort...

Accurate three-dimensional (3D) image segmentation techniques have become increasingly important for medical image analysis in general, and for spinal vertebrae image analysis in particular. The complexity of vertebrae shapes, gaps in the cortical bone and internal boundaries pose significant challenge for image analysis. In this paper, we describe a level set image segmentation framework that ...

Background: The aim of this study was to assess geometrical modifications the aneurysmal Thoracic Aorta (TA) after Endovascular Repair (TEVAR) over 3 years follow-up, identify features predicting unfavorable evolution.

IVPrototype is an Information Visualization Prototype for the visualization of both geometrical and non-geometrical data. Our goal is to provide a generic system that automatically generates data visualization and dynamically adapts the interface according to the data in order to control the amount of information displayed. The information is organized in one or several information groups, whic...

In binary tomography, several algorithms are known for reconstructing binary images having some geometrical properties from their projections. In order to choose the appropriate reconstruction algorithm it is necessary to have a priori information of the image to be reconstructed. In this way we can improve the speed and reduce the ambiguity of the reconstruction. Our work is concerned with the...

In this work we propose a scheme for analysis of the shape of a 3D model. We use Extended Reeb Graph to describe the topological structure of the model which we further enrich with extracted geometrical features. The nodes of the graph represent different components of the model, and we propose to analyze their shape separately. Shape characteristics such as taper/enlargement, average curvature...

This paper presents the idea to use linear symmetry properties as a feature based pre-processing step for fingerprint images. These features contain structural information of the local patterns. The linear symmetry can be computed by using separable spatial filtering and therefore has the potential to be a fast pre-processing step. Our results indicate that minutiae can be located as well as ca...