[mapserver-users] Mapserver WCS - how to return native pixel resolution data?

[Roger André]

Sorry for the spam, I think I found the answer.  Both RESX and RESY
need to be positive values.  Using that, I am able to get back data
that matches the original data.

Thanks,

Roger
--

On Thu, Mar 19, 2009 at 11:36 AM, Roger André <randre at gmail.com> wrote:
> Hi Alexander,
>
> Thanks for the response.  Yes, I am using a GetCoverage request that
> looks like this:
>
> http://localhost/cgi-bin/mapserv?map=/var/www/mapfiles/netCDF/netcdf.map
> &SERVICE=wcs
> &VERSION=1.0.0
> &REQUEST=GetCoverage
> &COVERAGE=elev
> &CRS=EPSG:4326
> &BBOX=125,50,130,55
> &WIDTH=600
> &HEIGHT=600
> &FORMAT=image/grid
>
> The source is a single-band image, and the data is correctly returned
> as either a single-band GeoTIFF, or an ASCII Grid, depending on which
> FORMAT I specify in the WCS string.
>
> What I would like to do is eliminate the WIDTH and HEIGHT parameters
> from the request, and just return whatever is available in the BBOX
> area.  When I remove them from the request, I get an error that says I
> either need HEIGHT and WIDTH, or RESX and RESY.  When I restructure
> the command to include RESX and RESY (see below), I get an "Out of
> memory" error.
>
> http://localhost/cgi-bin/mapserv?map=/var/www/mapfiles/netCDF/netcdf.map
> &SERVICE=wcs
> &VERSION=1.0.0
> &REQUEST=GetCoverage
> &COVERAGE=elev
> &CRS=EPSG:4326
> &BBOX=125,50,130,55
> &FORMAT=image/grid
> &RESX=.033&RESY=-.033
>
> I believe I should be able to use the pixel dimensions that are
> reported back to me in a DescribeCoverage request, which show them to
> be:
>
> <gml:offsetVector>0.033333333333333 0</gml:offsetVector>
> <gml:offsetVector>0 -0.033333333333333</gml:offsetVector>
>
> Thanks for the help,
>
> Roger
> --
>
> On Wed, Mar 18, 2009 at 6:51 PM, Alexander Petkov <greenkov at gmail.com> wrote:
>> On 3/18/09, Roger André <randre at gmail.com> wrote:
>>> Hi All,
>>>
>>>  I have a question which I'm not sure relates to the structure of a WCS
>>>  request, or the setup of my WCS server.  I have a tileset of SRTM
>>>  tiles that I would like to query by geographic region via WCS.  I have
>>>  basic functionality working, but I can't figure out how to make a
>>>  request via BBOX that only returns the actual pixels that are present
>>>  in the source data.  Is this possible?  I would think that as long as
>>>  I specified the matching SRS, I should be able to, but I've gotten
>>>  stuck.
>>
>> Are you using a WCS getcoverage request to get the data? Is the source
>> file a 1 band image? Is the returned data contaiining 3 bands? A
>> little more information will be of help to give a good answer.
>>
>> You are working in the right direction by configuring your WCS to
>> serve the actual data.
>>
>> In my case, I have 1 band palletted images, and with a getcoverage
>> request  for a bounding box I got the values, but as a grayscale
>> image. With some help from another user I managed to add the colormap
>> info from the class directives in my map file.
>>
>> The following output format is what worked to add a pallette to the
>> returned image:
>> OUTPUTFORMAT
>>   NAME "GTIFF"
>>   MIMETYPE "image/tiff"
>>   DRIVER "GDAL/GTiff"
>>   EXTENSION "tif"
>>   IMAGEMODE "PC256"
>>   TRANSPARENT TRUE
>>   FORMATOPTION "COMPRESS=DEFLATE"
>>   FORMATOPTION "ZLEVEL=9"
>>  END
>>
>