17.9 WCS Extensions Implemented
This topic describes the WCS Extensions implemented and gives examples of some elements defined by each extension.
It concludes with a GetCoverage request example that includes all the extensions.
11-053r1 OGC Web Coverage Service Interface Standard – CRS Extension
This WCS CRS Extension defines how to request and obtain a coverage in CRSs different from the Native CRS, and also how to provide a subsetting bounding box with coordinates in a CRS different from the Native CRS. A WCS server supporting this WCS CRS Extension announces the CRSs supported by listing their CRS Identifiers in its Capabilities document. For example:
<wcscrs:subsettingCrs>http://www.opengis.net/def/crs/EPSG/0/4326</wcscrs:subsettingCrs> <wcscrs:outputCrs>http://www.opengis.net/def/crs/EPSG/0/4326</wcscrs:outputCrs>
112-039 OGC Web Coverage Service Interface Standard – Scaling Extension
This extension allows scaling of a coverage along one or more of its axes during its server-side processing in a GetCoverage request. For example:
<scal:ScaleByFactor> <scal:axis>E</scal:axis> <scal:scaleFactor>0.5</scal:scaleFactor> </scal:ScaleByFactor>
112-040 OGC Web Coverage Service Interface Standard – Range Subsetting Extension
This extension allows extraction of specific fields, according to the range type specification, from the range set of a coverage during server-side processing of a coverage in a GetCoverage request. For example:
<rsub:RangeSubset> <rsub:RangeItem> <rsub:RangeComponent>band1</rsub:RangeComponent> </rsub:RangeItem> <rsub:RangeItem> <rsub:RangeInterval> <rsub:startComponent>band3</rsub:startComponent> <rsub:endComponent>band5</rsub:endComponent> </rsub:RangeInterval> </rsub:RangeItem> </rsub:RangeSubset>
112-049 OGC Web Coverage Service Interface Standard – Interpolation Extension
This extension gives control over interpolation of a coverage during its server-side processing.
This allows the WCS client to control and specify the interpolation mechanism to be applied to a coverage during server processing. For example:
<int:Interpolation> <int:globalInterpolation> http://www.opengis.net/def/interpolation/OGC/1/nearest-neighbor </int:globalInterpolation> </int:Interpolation>
112-100r1 OGC GML Application Schema – Coverages – GeoTIFF Coverage Encoding Profile
This encoding profile specifies the usage of the GeoTIFF data format for the encoding of GML coverages. For example:
<wcs:format>image/tiff</wcs:format>
Example Showing All Extensions
The following is an example of a GetCoverage request example with all extensions included:
<wcs:GetCoverage xmlns:wcs="http://www.opengis.net/wcs/2.0" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opengis.net/wcs/2.0 http://schemas.opengis.net/wcs/2.0/wcsAll.xsd" xmlns:scal="http://www.opengis.net/wcs/scaling/1.0" xmlns:wcscrs="http://www.opengis.net/wcs/service-extension/crs/1.0" xmlns:rsub="http://www.opengis.net/wcs/rangesubsetting/1.0" xmlns:int="http://www.opengis.net/wcs/interpolation/1.0" service="WCS" version="2.0.1"> <wcs:Extension> <wcscrs:subsettingCrs>http://www.opengis.net/def/crs/EPSG/0/4326</wcscrs:subsettingCrs> <wcscrs:outputCrs>http://www.opengis.net/def/crs/EPSG/0/4326</wcscrs:outputCrs> <rsub:RangeSubset> <rsub:RangeItem> <rsub:RangeComponent>L3</rsub:RangeComponent> </rsub:RangeItem> </rsub:RangeSubset> <int:Interpolation> <int:globalInterpolation> http://www.opengis.net/def/interpolation/OGC/1/nearest-neighbor </int:globalInterpolation> </int:Interpolation> <scal:ScaleByFactor> <scal:scaleFactor>0.5</scal:scaleFactor> </scal:ScaleByFactor> </wcs:Extension> <wcs:CoverageId>C0005</wcs:CoverageId> <wcs:DimensionSlice> <wcs:Dimension>N</wcs:Dimension> <wcs:SlicePoint>8.16270027015798</wcs:SlicePoint> </wcs:DimensionSlice> <wcs:DimensionTrim> <wcs:Dimension>E</wcs:Dimension> <wcs:TrimLow>112.990337346209</wcs:TrimLow> <wcs:TrimHigh>113.028655200765</wcs:TrimHigh> </wcs:DimensionTrim> <wcs:format>image/tiff</wcs:format> <wcs:mediaType>multipart/related</wcs:mediaType> </wcs:GetCoverage>
Parent topic: Web Coverage Service (WCS) Support