Changes between Version 25 and Version 26 of WKTRaster/Documentation01


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Timestamp:
Dec 9, 2009, 12:11:01 PM (14 years ago)
Author:
pracine
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  • WKTRaster/Documentation01

    v25 v26  
    207207 * expect existing applications to work with new data loaded as rasters without (many) changes (to a certain conceptual limit).
    208208
     209This makes PostGIS WKT Raster an abstraction level, not only over the raster format (like GDAL) or over the vector format (like OGR), but more generally over the two most used data structures in the geospatial industry (raster AND vector). Even if many operations performed on a vector object (e.g. all the functions working only on LINESTRING geometries) are not really possible to apply to raster objects, and if there are also some raster specific functions (e.g. ST_Resample() or ST_SetNoDataValue()) not working on vector objects, we think, and we will demonstrate as we extend PostGIS WKT Raster in the future, that most operations have their equivalent in both raster and vector worlds (e.g. ST_Intersections(), ST_Accum(), ST_Area(), ST_MapAlgebra()), even if this does not appear obvious at first sight.
     210
     211We think that providing a single paradigm (SQL) for dealing with both rasters and vectors should allow developers to write better GIS applications, by simplifying graphical user interfaces and softening the learning curves. Developers should be able to build a unique graphical user interface to deal with raster and vector data, making users having to learn only one set of operators to work with vector data and raster data, instead of two. We think this should generally enhance users’ experiences with geospatial applications and allow them to focus on real geographic problems rather than struggling with data formats and structures.
     212
     213We also think that this approach is compliant (at least in philosophy) with the ISO 19123 "Abstract Specification Schema for Coverage Geometry and Functions" specification (not to be confused with the OCG Web Coverage Service) in which a coverage can be represented as a point layer, a polygon layer, a TIN layer or a raster layer, and in which any positional value of the coverage is accessible without having to know the data structure upon which the coverage is based.
    209214
    210215== '''3.2 - Integration with PostGIS''' ==