In this work we introduce a curvature based shape feature extraction technique. To construct the proposed descriptor, first an input color channel is subject to edge detection and gradient computations. Then, based on the gradient map and edge map, the local curvature of the contour is computed for each pixel as the angular difference between the maximum and minimum gradient angle within a cert...

For generalized cylinders (GC) defined by contours of discrete curves, we propose two algorithms to generate GC surfaces (1) in polygonal meshes and (2) in cylindrical type of developable surface patches. To solve the contour blending problem of generalized cylinder, the presented algorithms have adopted the algorithms and properties of LIDM (linear interpolation by direction map) that interpol...

geological studies are basic formof operations for the exploration and development of oil and gas fields.preparation of topographical and geological maps and drawingcross section from thesemaps formspart of these operations. existing lineaments in the study area are important, and should be considered in drawing the geological sections. the evaluation of wells stability is one of the important ...

The knowledge of the surface topography has a major importance in the field of Earth sciences. It is essential in any discipline concerned with process modeling like hydrology, climatology, geomorphology and ecology. The present study utilized Environmental Systems Research Institute’s (ESRI) ArcGIS 9.3 (with the spatial analyst extension) software, remote sensing data ( DEM and Digital Aerial ...

Introduction: Accurate lesion segmentation is an important component of determining quantitative features for lesions on MRI. In this study, we develop an automated lesion segmentation method for delineating lesions on dynamic contrast enhanced (DCE)-MRI. We present a new active contour model which uses spectral embedding (SE), a process that partitions images in order to maximize intercluster ...

A large number of registration techniques rely on manually selected landmark points. A system based on neural principles has been developed to automatically extract landmark types and positional information from magnetic resonance images. A single self-organising map is used to develop the features (landmark types) so that the final landmarks represent statistically significant contour sections...

M. Violet Gray RBF Consulting Camarillo, California [email protected] Gould and White (1968) introduced the measurement and isoline mapping of regional preferences, producing preference or “isoeutope” maps. As cartographers know, the decision to employ isoline mapping as a cartographic display technique is valid insofar as certain assumptions are met, notably the assumption that the varia...

Historical maps are precious materials, which show spatial distribution of land use, streets and so on at the time the maps were produced. However, the imprecision, in the geometrical sense, of the historical maps makes the task of comparison very difficult. This drawback brings us to the idea of incorporating the historical maps into GIS after rubber-sheet transformation, i.e. geometric correc...

The transmission of the large store of information contained in 3D medical data sets through limited capacity channels, is a critical procedure in many telemedicine applications. In this paper, techniques are presented for the compression of visualizations of 3D image data for e cient storage and transmission. Methods are rst presented for the transmission of the 3D surface of the objects using...