[GRASS-user] gdal 1.5 and WMS ressource --- PREVIOUSLY:How to best access hundreds of orthophotos -- mapserver as WMS server?

Rainer_M_Krug1 · January 2, 2008, 5:27pm

Hi Dylan

you wrote in the a previous thread that one can use gdal 1.5 directly to access a WMS ressource which is defined in an xml file (see snippet below).
As 1.5 is out (and I compiled with MrSid support - works nicely by the way), I looked but could find no information on that feature. Could you please elaborate how I can use this instead of setting up a mapserver on localhost?

Thanks a lot,

Rainer

Dylan Beaudette wrote:
SNIP
> 7. once GDAL 1.5 is released it will be possible to an r.in.gdal and point it
> to an XML file defining a WMS resource. A mini-script might be able to
> construct the XML file on the fly...
>
> Unfortunately you will still have to manage the images that are imported into
> GRASS with GRASS commands, unless you constantly overwrite a temporary set of
> files by always using the same names and the --o flag.
>
SNIP

sebastian_sauer · January 2, 2008, 8:37pm

Wed 02 Jan 2008 18:27, Rainer M Krug wrote:

you wrote in the a previous thread that one can use gdal 1.5 directly to
access a WMS ressource which is defined in an xml file (see snippet below).
As 1.5 is out (and I compiled with MrSid support - works nicely by the
way), I looked but could find no information on that feature. Could you
please elaborate how I can use this instead of setting up a mapserver on
localhost?

my understanding was - feel free to correct me - dylan was refering to
the OGR/GDAL vrt driver.

http://www.gdal.org/gdal_vrttut.html
http://www.gdal.org/ogr/drv_vrt.html

s.

mlennert · January 2, 2008, 9:42pm

On 02/01/08 21:37, sebastian sauer wrote:

Wed 02 Jan 2008 18:27, Rainer M Krug wrote:

you wrote in the a previous thread that one can use gdal 1.5 directly to access a WMS ressource which is defined in an xml file (see snippet below).
As 1.5 is out (and I compiled with MrSid support - works nicely by the way), I looked but could find no information on that feature. Could you please elaborate how I can use this instead of setting up a mapserver on localhost?

my understanding was - feel free to correct me - dylan was refering to
the OGR/GDAL vrt driver.

http://www.gdal.org/gdal_vrttut.html
http://www.gdal.org/ogr/drv_vrt.html

I would rather guess it was the "WMS -- Web Map Services" driver:

http://www.gdal.org/frmt_wms.html

The page explains that you have to create an xml file such as this:

<GDAL_WMS>
     <Service name="WMS">
         <Version>1.1.1</Version>
         <ServerUrl>http://onearth.jpl.nasa.gov/wms.cgi?</ServerUrl>
         <SRS>EPSG:4326</SRS>
         <ImageFormat>image/jpeg</ImageFormat>
         <Layers>modis,global_mosaic</Layers>
         <Styles></Styles>
     </Service>
     <DataWindow>
         <UpperLeftX>-180.0</UpperLeftX>
         <UpperLeftY>90.0</UpperLeftY>
         <LowerRightX>180.0</LowerRightX>
         <LowerRightY>-90.0</LowerRightY>
         <SizeX>2666666</SizeX>
         <SizeY>1333333</SizeY>
     </DataWindow>
     <Projection>EPSG:4326</Projection>
     <BandsCount>3</BandsCount>
</GDAL_WMS>

I guess (but have never tried) that this would lead to an r.in.gdal line such as:

r.in.gdal in=YourFile.xml out=GRASSLayerName

Moritz

Rainer_M_Krug1 · January 3, 2008, 1:06pm

Moritz Lennert wrote:

On 02/01/08 21:37, sebastian sauer wrote:

Wed 02 Jan 2008 18:27, Rainer M Krug wrote:

you wrote in the a previous thread that one can use gdal 1.5 directly to access a WMS ressource which is defined in an xml file (see snippet below).
As 1.5 is out (and I compiled with MrSid support - works nicely by the way), I looked but could find no information on that feature. Could you please elaborate how I can use this instead of setting up a mapserver on localhost?

my understanding was - feel free to correct me - dylan was refering to
the OGR/GDAL vrt driver.

http://www.gdal.org/gdal_vrttut.html
http://www.gdal.org/ogr/drv_vrt.html

I would rather guess it was the "WMS -- Web Map Services" driver:

Ah - now I understand. I still have to set up a WMS server, but I can access it through gdal instead of using r.in.wms.

Thanks again,

Rainer

http://www.gdal.org/frmt_wms.html

The page explains that you have to create an xml file such as this:

<GDAL_WMS>
    <Service name="WMS">
        <Version>1.1.1</Version>
        <ServerUrl>http://onearth.jpl.nasa.gov/wms.cgi?</ServerUrl>
        <SRS>EPSG:4326</SRS>
        <ImageFormat>image/jpeg</ImageFormat>
        <Layers>modis,global_mosaic</Layers>
        <Styles></Styles>
    </Service>
    <DataWindow>
        <UpperLeftX>-180.0</UpperLeftX>
        <UpperLeftY>90.0</UpperLeftY>
        <LowerRightX>180.0</LowerRightX>
        <LowerRightY>-90.0</LowerRightY>
        <SizeX>2666666</SizeX>
        <SizeY>1333333</SizeY>
    </DataWindow>
    <Projection>EPSG:4326</Projection>
    <BandsCount>3</BandsCount>
</GDAL_WMS>

I guess (but have never tried) that this would lead to an r.in.gdal line such as:

r.in.gdal in=YourFile.xml out=GRASSLayerName

Moritz

mlennert · January 3, 2008, 2:48pm

On 03/01/08 14:06, Rainer M Krug wrote:

Moritz Lennert wrote:

On 02/01/08 21:37, sebastian sauer wrote:

Wed 02 Jan 2008 18:27, Rainer M Krug wrote:

you wrote in the a previous thread that one can use gdal 1.5 directly to access a WMS ressource which is defined in an xml file (see snippet below).
As 1.5 is out (and I compiled with MrSid support - works nicely by the way), I looked but could find no information on that feature. Could you please elaborate how I can use this instead of setting up a mapserver on localhost?

my understanding was - feel free to correct me - dylan was refering to
the OGR/GDAL vrt driver.

http://www.gdal.org/gdal_vrttut.html
http://www.gdal.org/ogr/drv_vrt.html

I would rather guess it was the "WMS -- Web Map Services" driver:

Ah - now I understand. I still have to set up a WMS server, but I can access it through gdal instead of using r.in.wms.

Well, if you have the data directly accessible, I don't know if it is the most efficient way to access it via a webserver and wms. The main insterest of this is obviously to get data from a distant wms server...

Moritz

Dylan_Beaudette1 · January 3, 2008, 9:06pm

On Wednesday 02 January 2008, Rainer M Krug wrote:

Hi Dylan

you wrote in the a previous thread that one can use gdal 1.5 directly to
access a WMS ressource which is defined in an xml file (see snippet below).
As 1.5 is out (and I compiled with MrSid support - works nicely by the
way), I looked but could find no information on that feature. Could you
please elaborate how I can use this instead of setting up a mapserver on
localhost?

Thanks a lot,

Rainer

Hi Rainer,

Yes, the new GDAL format (as also mentioned by others) is documented here:
http://www.gdal.org/frmt_wms.html

My suggestion, as quoted below, did not include replacing a _mapserver_ (WMS
source)- rather support for WMS would allow r.in.gdal to replace r.in.wms...
or perhaps re-write r.in.wms as a wrapper to r.in.gdal by first creating the
XML config file. See http://www.gdal.org/frmt_wms.html for details.

Cheers,

Dylan

Dylan Beaudette wrote:
SNIP

> 7. once GDAL 1.5 is released it will be possible to an r.in.gdal and

point it

> to an XML file defining a WMS resource. A mini-script might be able to
> construct the XML file on the fly...
>
> Unfortunately you will still have to manage the images that are

imported into

> GRASS with GRASS commands, unless you constantly overwrite a

temporary set of

> files by always using the same names and the --o flag.

SNIP

--
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341

Dylan_Beaudette1 · January 3, 2008, 9:10pm

On Thursday 03 January 2008, Moritz Lennert wrote:

On 03/01/08 14:06, Rainer M Krug wrote:
> Moritz Lennert wrote:
>> On 02/01/08 21:37, sebastian sauer wrote:
>>> Wed 02 Jan 2008 18:27, Rainer M Krug wrote:
>>>> you wrote in the a previous thread that one can use gdal 1.5
>>>> directly to access a WMS ressource which is defined in an xml file
>>>> (see snippet below).
>>>> As 1.5 is out (and I compiled with MrSid support - works nicely by
>>>> the way), I looked but could find no information on that feature.
>>>> Could you please elaborate how I can use this instead of setting up
>>>> a mapserver on localhost?
>>>
>>> my understanding was - feel free to correct me - dylan was refering to
>>> the OGR/GDAL vrt driver.
>>>
>>> http://www.gdal.org/gdal_vrttut.html
>>> http://www.gdal.org/ogr/drv_vrt.html
>>
>> I would rather guess it was the "WMS -- Web Map Services" driver:
>
> Ah - now I understand. I still have to set up a WMS server, but I can
> access it through gdal instead of using r.in.wms.

Well, if you have the data directly accessible, I don't know if it is
the most efficient way to access it via a webserver and wms. The main
insterest of this is obviously to get data from a distant wms server...

Moritz

Right. I think that within the context of the original discussion (?) the
point was access to a tiled, indexed image catalog of sorts. I had suggested
adding internal overviews to the pile of images (gdaladdo), creating a tile
index (gdaltindex), and then making the pile of images accessible via WMS
(mapserver) so that chunks of the entire virtual mosaic could be imported
into a GRASS region- either by r.in.wms (or r.in.gdal with some help).

If I get a chance to mess around with this, I will post back a worked out
example.

Cheers,

Dylan

--
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341