[gdal-dev] WCS driver work

[Ari Jolma]

Ari Jolma kirjoitti 14.11.2017 klo 17:41:
> I've got very close to being able to get valid data (visual comparison 
> in QGIS) from various server types and WCS versions.
>
> I've documented the results here: 
> https://trac.osgeo.org/gdal/wiki/WCS%2Binteroperability
>
> It seems that I need eight option flags to cover all cases. Mostly the 
> problems are with CRS that have inverted axis order. Also it seems to 
> be a problem if the server or the standard does not support requesting 
> directly tiles of specific size. It is especially a problem since GDAL 
> fails the call if the size is not expected.
>
> The only combination that I have not yet managed to get to work is 
> GeoServer with version 1.1 and inverted axis order. I can get a decent 
> response but the returned geotiff has slightly wrong size (59x38 
> instead of 60x38). The problematic call is below[1].

I was able to fix this by computing the pixel size a bit differently 
(kind of numeric problem again, since you want n pixels, the pixel size 
needs to be computed like you need n+0.5 pixels).

Ari

>
> Also, I have/know only a few servers and I lack some combinations; 
> I've also found a server with a combination that I've managed to test 
> ok, but whose behavior I can't yet explain[2].
>
> I'm writing documentation and test code but the latter will still take 
> some time to be ready for the trunk.
>
> The code is at https://github.com/ajolma/gdal/tree/trunk/gdal/frmts/wcs
>
> I've also made one ticket regarding port code 
> https://trac.osgeo.org/gdal/ticket/7141
>
> Ari
>
> [1] 
> https://msp.smartsea.fmi.fi/geoserver/wcs?SERVICE=WCS&VERSION=1.1.0&REQUEST=GetCoverage&IDENTIFIER=smartsea%3Aeusm2016-EPSG2393&FORMAT=image%2Ftiff&BOUNDINGBOX=6620001.14539506,3199988.18514013,6670001.21326246,3279980.29051582,urn:ogc:def:crs:EPSG::2393&RangeSubset=contents&GridBaseCRS=urn:ogc:def:crs:EPSG::2393&GridCS=urn:ogc:def:cs:OGC:0.0:Grid2dSquareCS&GridType=urn:ogc:def:method:WCS:1.1:2dGridIn2dCrs&GridOrigin=6670001.21326246,3199988.18514013&GridOffsets=0,1333.20175626157,-1315.79125966838,0
>
> [2] 
> https://lists.osgeo.org/pipermail/mapserver-users/2017-November/080339.html
>
>