Minimum bounding rectangle: Difference between revisions

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==MBRs as spatial metadata==

Owing to their simplicity of expression and ease of use for searching, MBRs (frequently as "bounding box" or "bounding coordinates") are also commonly included in relevant standards for [[geospatial metadata]], i.e. [[metadata]] that describes spatial (geographic) objects; examples include [http://dublincore.org/documents/dcmi-box/index.shtml DCMI Box] as an extension to the [[Dublin Core]] metadata scheme, "Bounding Coordinates" in the [http://www.fgdc.gov/standards/projects/FGDC-standards-projects/metadata/base-metadata/v2_0698.pdf (U.S.) FGDC metadata standard], and "Geographic Bounding Box" in the (2003-current) '''ISO 19115 Metadata Standard''' for geographic information ([[ISO/TC 211]]). It is also (as "boundingBox") an element in [[Geography Markup Language]] (GML), that is utilised by a range of Web Service specifications from the [[Open Geospatial Consortium]] (OGC). In the '''ISO 19107 Spatial Schema''' (ISO/TC 211), MBR appears as the datatype GM_Envelope that is returned by the envelope() operation on the root class GM_Object.

==Syntax examples==

The following example in [[Geography Markup Language]] (GML) has been provided courtesy of Dr. Simon Cox:

<gml:boundedBy>

<gml:Envelope srsName="urn:x-ogc:def:CRS:EPSG:27354"> <!-- I assume you checked the EPSG code ... -->

<gml:lowerCorner>-73.933217 40.78587</gml:lowerCorner>

<gml:upperCorner>-73.768722 40.914404</gml:upperCorner>

</gml:Envelope>

</gml:boundedBy>

The next example is provided from the ISO 19115 standard for [[geospatial metadata]]:

<EX_GeographicBoundingBox>

<westBoundLongitude>...</westBoundLongitude>

<eastBoundLongitude>...</eastBoundLongitude>

<southBoundLatitude>...</southBoundLatitude>

<northBoundLatitude>...</northBoundLatitude>

</EX_GeographicBoundingBox>

==Further reading==