I am trying to use the new GDAL_WMTS driver with GDAL Version 2.1. Problem: The thread that receives the data from the server gets a GDAL data set handle with a total data buffer size of 4,294,967,296 for a 4 band image.
Questions: 1. Does GDAL_WMTS driver return all tiles combined into a single image memory buffer? 2. Is the data buffer returned for WMTS retrieved the same way as for WMS with a call to the GDAL Data Set rasterio function? 3. Is there any way to control which tile level in the TileMatrixSet is returned for GDAL_WMTS? A TileLevel tag is in the GDAL_WMS XML definition http://www.gdal.org/frmt_wms.html but not in the GDAL_WMTS definition/example http://www.gdal.org/frmt_wmts.html According to the returned data parameters, the image is huge 32K x 32K x 4 with around 4GB of memory needed to create a 4 band image. The area requested is a fairly small area around the Cumberland River. Here’s a sample of the Service Request sent to the WMTS server. The XML is similar to the request generated by GDAL_Translate for the server. The DataWindow coordinates are much smaller and in range of the server’s data. Request coordinates were converted from EPSG:26926 to EPSG:3857 for the request shown below. <GDAL_WMTS> <GetCapabilitiesUrl>http://basemap.nationalmap.gov/arcgis/rest/services/USGSShadedReliefOnly/MapServer/WMTS/1.0.0/WMTSCapabilities.xml</GetCapabilitiesUrl> <Layer>USGSShadedReliefOnly</Layer> <TileMatrixSet>default028mm</TileMatrixSet> <DataWindow> <UpperLeftX>-9664344.849763</UpperLeftX> <UpperLeftY>4328551.472775</UpperLeftY> <LowerRightX>-9646502.672226</LowerRightX> <LowerRightY>4318753.685277</LowerRightY> </DataWindow> <BandsCount>4</BandsCount> <Cache /> <UnsafeSSL>true</UnsafeSSL> <ZeroBlockHttpCodes>204,404</ZeroBlockHttpCodes> <ZeroBlockOnServerException>true</ZeroBlockOnServerException> </GDAL_WMTS> With the exception of the DataWindow parameters, the request matches the test request generated by GDAL_Translate for the server. The DataWindow values are well within the full range of the WMTS Server for the requested layer. Thanks in advance! Elaine -- View this message in context: http://osgeo-org.1560.x6.nabble.com/GDAL-WMTS-Driver-How-do-you-control-the-Tile-Matrix-Set-s-Tile-Level-tp5294530.html Sent from the GDAL - Dev mailing list archive at Nabble.com. _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
