[gdal-dev] Using VRT images with derived bands (pixel function) with MapServer

[Armin Burger]

Hello Yves

I succeeded to get it running with Mapserver, after some testing and 
additional settings also with PHP MapScript. For others who might be 
interested in the various steps, I added a short how-to to the Mapserver 
Wiki, see

http://trac.osgeo.org/mapserver/wiki/RasterVrtDerivedBands

Thanks again for the help!

Armin


On 16/02/2012 18:30, Yves Jacolin (free) wrote:
> Hello,
>
> I used the Makefile file in an archive I found in a GDAL ticket. So I guess I am
> using a .so file.
>
> Y.
> Le jeudi 16 février 2012 10:15:58, Armin Burger a écrit :
>> Yves
>>
>> thanks a lot for the help.
>>
>> So it is sufficient to add SetEnv GDAL_DRIVER_PATH ..., place the file with
>> the pixel function there, and Mapserver can find pixel function referenced
>> in the VRT file? What kind of compilation did you use? Create a shared
>> library *.so or is the *.o object file sufficient?
>>
>> Armin
>>
>>
>> -------- Original-Nachricht --------
>>
>>> Datum: Thu, 16 Feb 2012 09:31:11 +0100
>>> Von: Yves Jacolin<yjacolin at free.fr>
>>> An: gdal-dev at lists.osgeo.org, armin.burger at gmx.net
>>> Betreff: Re: [gdal-dev] Using VRT images with derived bands (pixel
>>> function) with MapServer
>>>
>>> Armin,
>>>
>>> I am using such application stack: netcdf>  vrt and pixel functions>
>>> GDAL
>>>
>>> MapServer
>>>
>>> We have a tiled layer inside PostGIS and we juste configure the layer
>>> like all
>>> other tiled datasource:
>>>
>>> LAYER
>>>
>>>   STATUS ON
>>>   NAME "layer_idx"
>>>   TYPE POLYGON
>>>   CONNECTION "dbname=mydb host=localhost user=myUser password=mypassword"
>>>   CONNECTIONTYPE postgis
>>>   DATA "the_geom FROM myLayer USING srid=4326"
>>>   PROJECTION
>>>
>>>    "init=epsg:4326"
>>>
>>>   END
>>>   METADATA
>>>
>>>     "wms_srs"   "EPSG:4326"
>>>     "wms_timeextent" "2010-12-20/2010-12-26"
>>>     "wms_timeitem" "datetime" #column in postgis table of type timestamp
>>>     "wms_timedefault" "2010-12-24T00:00:00Z"
>>>     "wms_enable_request" "*"
>>>
>>>   END
>>>
>>> END
>>>
>>> If you want to use the vrt file directly it is also possible as easily
>>> as: DATA "vrt/myLayer.vrt"
>>>
>>> About register the plugin, in Apache config you have to use SetEnv this
>>>
>>> way:
>>>     SetEnv GDAL_DRIVER_PATH  directory/mapserver/misc
>>>     SetEnv MS_MAPFILE directory/mapserver/mymapfile.map
>>>     SetEnv MS_MAPFILE_PATTERN "^directory/mapserver/mymapfile.map"
>>>
>>> Hth,
>>>
>>> Y.
>>>
>>> Le Mercredi 15 Février 2012 19:52:21 Armin Burger a écrit :
>>>> Dear all
>>>>
>>>> I would be interested in using VRT images with "derived bands" as
>>>> described on the VRT image documentation page. This requires the
>>>> definition of a pixel function and the registration of this function in
>>>> the used application via "GDALAddDerivedBandPixelFunc".
>>>>
>>>> The provided sample function is already towards what I'm looking for. I
>>>> would just need to adapt it accordingly (calculating band 1 as
>>>> combination of source band 1 and 3).
>>>>
>>>> Since my main interest is to use such image definition in the context
>>>> of Mapserver, my question is if there could be a way to use this also
>>>> from Mapserver as application? If yes, where would I need to register
>>>> the function and how would I best make the function available to
>>>> Mapserver (maybe via an .o file that is created when compiling)? Maybe
>>>> somewhere inside mapgdal.c ?
>>>>
>>>> Would such a pixel function be used also in case when not the full
>>>> resolution image (i.e. TIFF file referenced in the VRT file) is read
>>>> but one of the overviews from the .ovr file associated to the Tiff
>>>> file?
>>>>
>>>> Thanks in advance for any hints
>>>>
>>>> Armin
>>>> _______________________________________________
>>>> gdal-dev mailing list
>>>> gdal-dev at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>