In this study, contours of a brain tumor on a single slice tomography image were derived by using image correlation technique. Four different methods were used to compare the validity of the derived contours. Contour map of the brain tumor was generated by using 2D image correlation technique with raw pixel , perceived brightness (luminance), optical density and Relative radiation dose data. Th...

Speckle and low contrast make ultrasound image segmentation a difficult task. This paper presents an original robust active contour energy and the corresponding quasi-automatic initialization. Both are based on the coefficient of variation gradient vector fl ow. Our approach combines anisotropic diffusion with the gradient vector fl ow field. The gradient vector fl ow is calculated from a map o...

A variety of operations have been described in recent years that are intended as digital solutions to a basic class of cartographic adjacency problems. A selection of these algorithms includes: interpolation; Voronoi diagrams of point distributions (proximal maps, Thiessen polygons); skeleton encoding (of scanned characters or polygons); corridor selection, or extraction of regions within speci...

This paper presents a new algorithm of disparity map segmentation in planar facets. Originalities of this method lies in the process of dense disparity map estimation, using the dynamic programming subject to interest points previously extracted. The segmentation of this map uses the normal vector at each pixel surface. The matching of pixels between the two images by dynamic programming provid...

We investigated whether observers use rate of change of curvature in visually extrapolating contour shape. Arcs of Euler spirals with positive or negative rate of change of curvature gamma (hence linearly increasing or decreasing curvature) disappeared behind the straight-edge of a half-disk occluder. Observers adjusted the position and the orientation of a line probe around the curved portion ...

Controlled Flight into Terrain is one of the major sources of accidents in aviation today. Studies have shown that the use of Terrain Awareness and Warning Systems (TAWS) can decrease the number of such accidents. A problem with current TAWS is that the majority of them use the same display window as other information such as weather, traffic, airport positions, and moving map programs. The amo...

Thematic map effectiveness can be defined only in terms of specific user requirements. Consideration of common requirements results in four criteria by which map effectiveness is evaluated: effectiveness for direct acquisition of both specific and general information and for memory of both specific and general information. The influence of visual map complexity and two methods of symbolization ...

This paper presents an edge-based segmentation technique that allows to process quickly very large range images. The proposed technique consists of two stages. First, a binary edge map is generated; then, a contour detection strategy is responsible for the extraction of the dizerent boundaries. The jirst stage generates a binary edge map based on a scan line approximation technique. There is a ...

Map digitization is still an ongoing research in development of GIS, photogrammetry, remote sensing, military, urban planning and etc. Majority of recent approach, either associates with human interaction or semi-automated process are insufficient in various aspects. There are usually time-consuming, inefficient, and shown inaccuracies in digitized data. This research is intended to develop an ...

Terrains are an essential part of outdoor environments. Terrain models are important for computer games and applications in architecture, urban design and archaeology. A popular and intuitive way to represent terrains is by contour maps. In order to render such representations in 3D the contours must be labelled with height values and converted to Digital Elevation Maps (DEM), which are regular...