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The voxel model is the logical extension of the raster data model, by tessellating three-dimensional space into cubes called voxels (a portmanteau of volume and pixel, the latter being itself a portmanteau). NetCDF is one of the most common data formats that supports 3-D cells. [30]
The fundamental strategy underlying the raster data model is the tessellation of a plane, into a two-dimensional array of squares, each called a cell or pixel (from "picture element"). In digital photography , the plane is the visual field as projected onto the image sensor ; in computer art , the plane is a virtual canvas; in geographic ...
A data model in Geographic information systems is a mathematical construct for representing geographic objects or surfaces as data. For example, the vector data model represents geography as points, lines, and polygons; the raster data model represents geography as cell matrixes that store numeric values;
There are some important advantages and disadvantages to using a raster or vector data model to represent reality: Raster datasets record a value for all points in the area covered which may require more storage space than representing data in a vector format that can store data only where needed. Raster data is computationally less expensive ...
In 1989, Peter Baumann started a research on database support for images, then at Fraunhofer Computer Graphics Institute.Following an in-depth investigation on raster data formalizations in imaging, in particular the AFATL Image Algebra, he established a database model for multi-dimensional arrays, including a data model and declarative query language.
Data from Conservation International on areas of the world with especially high endemism and high numbers of threatened species. Pilot Analysis of Global Ecosystems: Forest Ecosystems: Data from the World Resources Institute includes: percentage tree-cover, population density and tree cover, share of wood in fuel consumption, etc.
Data input is therefore flexible and fewer points need to be stored than in a raster DEM, with regularly distributed points. While a TIN may be considered less suited than a raster DEM for certain kinds of GIS applications, such as analysis of a surface's slope and aspect, it is often used in CAD to create contour lines. A DTM and DSM can be ...
TerraLib is an open-source GIS software that extends object-relational DBMS technology to handle spatio-temporal data types; while main focus is on vector data, there is also some support for rasters. Starting with version 2.0, PostGIS embeds raster support for 2-D rasters; a special function offers declarative raster query functionality.