This paper describes the generation of shape primitive detecting masks and their application in measurements on shapes as well as in conditions for topology preservation as used in skeletonization. The formalism is expanded from twoto four-dimensional images and elaborates on the extension of 3D skeletonization to 4D skeletonization. 2002 Elsevier Science B.V. All rights reserved.

In this paper we introduce a new method for computing the orientation for compound shapes. If the method is applied to single component shapes the computed orientation is consistent with the shape orientation defined by the axis of the least second moment of inertia. If the new method is applied to compound shapes this is not the case, and consequently the presented method is both new and diffe...

Diabetic Retinopathy is a medical condition where the retina is damaged because fluid leaks from blood vessels into the retina. The presence of hemorrhages in the retina is the earliest symptom of diabetic retinopathy. The number and shape of hemorrhages is used to indicate the severity of the disease. Early automated hemorrhage detection can help reduce the incidence of blindness. This paper i...

We propose two possible representative models for a 2D fracture in reservoirs. The first one simulates the fracture as a low-aspect ratio elliptical cylinder. The inner properties of this elliptical cylinder are assumed to be homogeneous and different from the surrounding medium that is also homogenous. This model can approximately describe the actual shape of fractures observed in the field, a...

A superelasticity (shape memory) behavior has been discovered for the superlattice-structured ZnO nanohelices. By in situ manipulation using a nanoprobe, the nanohelix could elastically recover its shape after an extremely large axial stretching to a degree close to the theoretical limit, while suffering little residual plastic deformation. As a result, its spring constant can be increased cont...

OBJECTIVE This study evaluated, in vitro, the fracture resistance of human non-vital teeth restored with different reconstruction protocols. MATERIAL AND METHODS Forty human anterior roots of similar shape and dimensions were assigned to four groups (n=10), according to the root reconstruction protocol: Group I (control): non-weakened roots with glass fiber post; Group II: roots with composit...

The Problem: The goal of low-level vision is to estimate an underlying scene (e.g., albedos or shapes), given an observed image. Real-world scenes can be very complex, conventionally requiring high dimensional representations that are hard to estimate and store. In this work, we propose a low-dimensional representation, called a scene recipe, that relies on the image itself to describe the comp...

Most structure from motion work assume that tracking is a separate issue from recovery of structure and motion. This paper argues that in certain cases, it helps to use the original images to refine the tracks in the course of estimating structure and motion. We illustrate this by presenting two algorithms: one for appearance-based structure from complete rotation, and another for 3-D face mode...

We provide exact shape reconstruction formulas in the spirit of the Linear Sampling method for a class of inverse problems in shape determination in the context of timeindependent partial differential equations. To this end, we prove a general theorem how, and under which assumptions, domain characterizations based on the range of the square root of an operator transform into domain characteriz...

We present a model-based method for detailed automatic building reconstruction from images. The method starts with recovering a coarse building model consisting of the main object planes. This model is upgraded by detecting deviations from the planes and fitting predefined shape primitives to these deviations to refine the geometry. The proposed method is presented on real datasets.