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For example, a data model for a city would include a list of data layers to be included (e.g., roads, buildings, parcels, zoning), with each being specified with the type of generic spatial data model being used (e.g. raster or vector), choices of parameters such as coordinate system, and its attribute columns.
This is an accepted version of this page This is the latest accepted revision, reviewed on 2 December 2024. Computer graphics images defined by points, lines and curves This article is about computer illustration. For other uses, see Vector graphics (disambiguation). Example showing comparison of vector graphics and raster graphics upon magnification Vector graphics are a form of computer ...
Vector data can be displayed as vector graphics used on traditional maps, whereas raster data will appear as an image that may have a blocky appearance for object boundaries. (depending on the resolution of the raster file). Vector data can be easier to register, scale, and re-project, which can simplify combining vector layers from different ...
The core functionality added by a spatial extension to a database is one or more spatial datatypes, which allow for the storage of spatial data as attribute values in a table. [4] Most commonly, a single spatial value would be a geometric primitive (point, line, polygon, etc.) based on the vector data model.
There are also many different types of geodata, including vector files, raster files, geographic databases, web files, and multi-temporal data. Spatial data or spatial information is broader class of data whose geometry is relevant but it is not necessarily georeferenced , such as in computer-aided design (CAD), see geometric modeling .
GRASS supports raster and vector data in two and three dimensions. The vector data model is topological, meaning that areas are defined by boundaries and centroids; boundaries cannot overlap within one layer. In contrast, OpenGIS Simple Features, defines vectors more freely, much as a non-georeferenced vector illustration program does.
Raster or gridded data may be the result of a gridding procedure. A single numeric value is then stored for each pixel. For most images, this value is a visible color, but other measurements are possible, even numeric codes for qualitative categories. Each raster grid has a specified pixel format, the data type for each
Data management, including the creation, editing, and storage of geographic data, as well as transformations such as changing coordinate systems and converting between raster and vector models. Spatial analysis, including a range of processing tools from basic queries to advanced algorithms such as network analysis and vector overlay