[postgis-users] Raster + Geometry Intersection

[Ed Linde]

Hi Pierre,
I will be back on in a couple of hours.. have to rush out. But thanks a
million for all your suggestions! Cannot get this working without your
help! :)

Cheers,
Ed

On Mon, Feb 27, 2012 at 3:59 PM, Ed Linde <edolinde at gmail.com> wrote:

> ok, just to get this right.. :) , you are suggesting I keep my OSM as is
> (id: 900913). Load in the tif rasters as srid (4326) and then "reproject"
> the OSM road geometry to srid = 4326 right? So it matches the srid of my
> raster! I ask because you said to reproject to 900913 in your mail.
>
> Cheers,
> Ed
>
>
> On Mon, Feb 27, 2012 at 3:53 PM, Pierre Racine <
> Pierre.Racine at sbf.ulaval.ca> wrote:
>
>> > I checked the srids of the geometry and the rasters and they are both
>> now set to
>> > --> 900913!
>>
>> But you loaded the raster with -s 900913. Right? That does not make the
>> raster coordinates to be transformed. You actually corrupted your rasters.
>> You have to load them in their proper srid (4326) and reproject them
>> afterward (or reproject the geometries) to 900913. I would go with
>> reprojecting the geometries.
>>
>> > I was using qgis and I think I made a mistake because I think the tif
>> files on disk
>> > are using srid = 4326, while the postgis layer I added was using 900913
>> for osm.
>> > I have never used OpenJump.. is it possible to view both my raster and
>> road
>> > geometries from postgis on to qgis? Or you recommend installing
>> OpenJump?
>>
>> I do. It's still the best/stable tool to work both raster and vectors.
>> You can't display raster but you can display their extent and their
>> vectorization (with ST_DumpAsPolygon()) as in the tutorial.
>>
>> > Also, do I still need to do some sort of reprojection on the
>> geometries? Is the
>> > SRID of 900913 reported for my rasters...reliable information?
>>
>> Again, the loader do not reproject. It just assign the srid you tell him.
>> You have to reproject at some point (before or after loading, before or
>> while intersecting).
>>
>> Pierre
>> _______________________________________________
>> postgis-users mailing list
>> postgis-users at postgis.refractions.net
>> http://postgis.refractions.net/mailman/listinfo/postgis-users
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20120227/42cd90b6/attachment.html>