[gdal-dev] WCS GetCoverage with AxisOrder swap

Ari Jolma ari.jolma at gmail.com
Thu Nov 9 06:12:06 PST 2017


Ari Jolma kirjoitti 09.11.2017 klo 15:52:
> jratike80 kirjoitti 09.11.2017 klo 15:18:
>> Piero Campa wrote
>>>> And for WCS subsetting, when you write something like
>>>> SUBSET=AXIS_NAME(min,max),
>>>> ​ ​
>>>> where AXIS_NAME should come from ? From the RectifiedGrid.axisLabels I
>>>> guess ?
>>>>
>>>>>> ​NO, subsetting/subspacing​ is meant to work aligned with the 
>>> coordinate
>>> system (!)
>>> You choose your (sub)space of interest, and then the server will filter
>>> out
>>> all the grid points that get included in that space, independently 
>>> of its,
>>> say, geometric profile (indeed in extreme settings, what you get 
>>> might not
>>> be a grid! see below)
>> Hi,
>>
>> When Ari gets totally familiar with this then he will like to continue.
>> About the first new thing he wants to do will be to get response from 
>> WCS
>> with non-native pixel size. The he starts to read the Scaling extension
>> https://portal.opengeospatial.org/files/12-039 and then he learns that
>> scaling is done in the RectifiedGrid domain and 
>> RectifiedGrid.axisLabels are
>> exactly what he must use. Poor man.
>
> I had this in my code already
>
> if (scaled) {
>         // scaling is expressed in grid axes
>         std::vector<CPLString> grid_axes = 
> Split(CPLGetXMLValue(psService, "GridAxes", ""), ",");
>         tmp.Printf("&SCALESIZE=%s(%i),%s(%i)", grid_axes[0].c_str(), 
> nBufXSize, grid_axes[1].c_str(), nBufYSize);
>         request += tmp;
>     }
>
> However, I have not yet tested it. I.e., GDAL gives me (the driver) a 
> buffer where to write. I'm reasoning I should use the scalesize. The 
> GridAxes is saved from the coverage description.

Now I have, all with the axis order swapped CRS. MapServer and Rasdaman 
return fine geotiffs. GeoServer returns something that GDAL complains 
"Returned tile does not match expected configuration. Got 13x20 instead 
of 20x13.", which is expected since with GeoServer I'm having the grid 
axis order problems.

Ari



More information about the gdal-dev mailing list