Le samedi 07 juillet 2012 08:45:33, Jukka Rahkonen a écrit : > Hi, > > National Land Survey of Finland has opened an experimental WMTS service. > GetCapabolities is found from > http://karttatiili.fi/dataset/taustakarttasarja/capabilities/wmts.xml??REQU > EST=GetCapabilities Unfortunately GDAL does not have a WMTS driver yet. Are > there any plans for making such?
This is something I've also thought to. At first sight WMTS shouldn't be so different of other tiled protocols (WMS-C, TMS, etc..), but there's an annoying difficulty : in WMTS, the different overview levels have not necessarily the same spatial extent (in the server you are mentionning, this seems to be indeed the case (*)), which doesn't fit natively into the GDAL model. An idea would be to take into account the tiling scheme and spatial extent of the most precise level, and use perhaps a in-memory VRT to do on-the-fly clipping of the overview levels. But that doesn't fit very well in the architecture of the "minidrivers" of the WMS driver. (*) You can see it by downloading the 4 following tiles at level 10 : http://kansalaisen.karttatiili.fi/dataset/taustakarttasarja/service/wmts?STYLES=_null&SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=taustakartta_10k&STYLE=_null&TILEMATRIXSET=EPSG_3067_MML&TILEMATRIX=EPSG_3067_MML%3A10&TILEROW=10000&TILECOL=1500&FORMAT=image%2Fpng http://kansalaisen.karttatiili.fi/dataset/taustakarttasarja/service/wmts?STYLES=_null&SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=taustakartta_10k&STYLE=_null&TILEMATRIXSET=EPSG_3067_MML&TILEMATRIX=EPSG_3067_MML%3A10&TILEROW=10000&TILECOL=1501&FORMAT=image%2Fpng http://kansalaisen.karttatiili.fi/dataset/taustakarttasarja/service/wmts?STYLES=_null&SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=taustakartta_10k&STYLE=_null&TILEMATRIXSET=EPSG_3067_MML&TILEMATRIX=EPSG_3067_MML%3A10&TILEROW=10001&TILECOL=1500&FORMAT=image%2Fpng http://kansalaisen.karttatiili.fi/dataset/taustakarttasarja/service/wmts?STYLES=_null&SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=taustakartta_10k&STYLE=_null&TILEMATRIXSET=EPSG_3067_MML&TILEMATRIX=EPSG_3067_MML%3A10&TILEROW=10001&TILECOL=1501&FORMAT=image%2Fpng And then the one that, in a classical tiling scheme, should cover the same area at level 9 : http://kansalaisen.karttatiili.fi/dataset/taustakarttasarja/service/wmts?STYLES=_null&SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=taustakartta_10k&STYLE=_null&TILEMATRIXSET=EPSG_3067_MML&TILEMATRIX=EPSG_3067_MML%3A9&TILEROW=5000&TILECOL=750&FORMAT=image%2Fpng But if you reassemble the 4 tiles of level 10, you'll see that the tile of level 9 is located at the north, with a shift of the height of a tile of level 10. This indeed comes from the TileMatrix definition, where one can see that the top of each level is not the same. And indeed, as ScaleDenominator=7142.857142857143 is equivalent to 2 m and ScaleDenominator=3571.4285714285716 is equivalent to 1 m, one can see that the tile at row=0 at level 10 is at the half of tile at row = 0 at level 9. <TileMatrix> <ows:Identifier>EPSG_3067_MML:9</ows:Identifier> <ScaleDenominator>7142.857142857143</ScaleDenominator> <TopLeftCorner>0.0 1.0000384E7</TopLeftCorner> <TileWidth>256</TileWidth> <TileHeight>256</TileHeight> <MatrixWidth>19532</MatrixWidth> <MatrixHeight>19532</MatrixHeight> </TileMatrix> <TileMatrix> <ows:Identifier>EPSG_3067_MML:10</ows:Identifier> <ScaleDenominator>3571.4285714285716</ScaleDenominator> <TopLeftCorner>0.0 1.0000128E7</TopLeftCorner> <TileWidth>256</TileWidth> <TileHeight>256</TileHeight> <MatrixWidth>39063</MatrixWidth> <MatrixHeight>39063</MatrixHeight> </TileMatrix> > > -Jukka Rahkonen- > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
