The aim of this work is the extraction of edges from Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) images by a deformable contour procedure, using an external force field derived from an anisotropic flow. Moreover, we introduce a divergence map in order to check the convergence of the process. As we know from vector calculus, divergence is a measure of the magnitude of a v...

Many applications, such as contour machining, rapid prototyping, and reverse engineering by laser scanner or coordinate measuring machine, involve sampling of free-from surfaces along section cuts by a family of parallel planes with equidistant spacing ∆ and common normal N. To ensure that such planar sections provide faithful descriptions of the shape of a surface, it is desirable to choose th...

In this paper we discuss the evaluation criteria for superquadric models recovered from the range data. We present arguments to support our belief that both quantitative and qualitative measures are required in order to evaluate a superquadric fit. The concept of superquadric contraction and dilation is introduced and used to derive a novel interpretation of the modified superquadric inside-out...

It is an expensive and time consuming task to digitize 1:25000 scaled maps which are made in the past with analogue methods. The development in digital image processing depending on the development of hardware technology made this process less expensive and faster. This study is based on this reality. In this thesis a new algorithm which aims to decrease human work time by making the work carri...

Among the many 3D face matching techniques that have been developed, are variants of 3D facial curve matching, which reduce the amount of face data to one or a few 3D curves. The face’s central profile, for instance, proved to work well. However, the selection of the optimal set of 3D curves and the best way to match them has not been researched systematically. We propose a 3D face matching fra...

This paper presents a novel variational and Partial Differential Equation (PDE)based method to link edge points into closed contours. First, an ending point restrained energy function, which improves the one used in the Gradient Vector Flow (GVF) Snake model, is proposed to derive an ending point restrained Gradient Vector Flow (ERGVF) field. When there are broken edges in the edge map, the GVF...

The size and physical structure of the Leptospira interrogans genome was characterized using contour-clamped homogenous electric field (CHEF) gel electrophoresis. The L. interrogans genome is approximately 4750 kb in size and is composed of two molecular species of DNA: a 4400 kb chromosome; and a 350 kb plasmid, pLIN1. A physical map of the chromosome was constructed with the restriction enzym...

This paper describes a method for extracting roads from a large scale unstructured 3D point cloud of an urban environment consisting of many superimposed scans taken at different times. Given a road map and a point cloud, our system automatically separates road surfaces from the rest of the point cloud. Starting with an approximate map of the road network given in the form of 2D intersection lo...