Re: [gdal-dev] Raster/vector intersections in PostGIS WKT Raster

[Ivan Lucena]

Christian,

How did you added support for Oracle GeoRaster on GeoTools/GeoServer? Did you use the Oracle GeoRaster Java API or GDAL? Is that available?

I am looking forward to use it.

Regards,

Ivan


>  -------Original Message-------
>  From: christian.mueller at nvoe.at
>  To: Pierre Racine <Pierre.Racine at sbf.ulaval.ca>
>  Cc: gdal-dev at lists.osgeo.org <gdal-dev at lists.osgeo.org>
>  Subject: Re: [gdal-dev] Raster/vector intersections in PostGIS WKT Raster
>  Sent: Jun 29 '10 11:46
>  
>  Hi, superb job. Congratulations.
>  
>  I am a geotools/geoserver developer and one of my jobs is fetching  
>  image tiles  or the corresponding pyramid tiles from jdbc data  
>  sources. Some weeks ago, I added support for Oracle Georaster and I  
>  want to support WKT Georaster too.
>  
>  wktraster makes it quite simple to achieve this. Is there any database  
>  layout you recommend. (A table for the image and one for each pyramid,  
>  or put all the tiles into one table having an attribute "level",.....).
>  
>  I have seen "gdal2wktraster.py", is this the recommended way to import  
>  tiles into postgis ?
>  What is the table layout created/needed by this utility ?
>  
>  Cheers
>  Christian
>  
>  
>  
>  Quoting Pierre Racine <Pierre.Racine at sbf.ulaval.ca>:
>  
>  > Hi everybody,
>  >
>  > I'm pleased to announce that you can now do intersections between  
>  > rasters and geometries very much like you used to do  
>  > geometry/geometry intersections in PostGIS. For this, PostGIS WKT  
>  > Raster introduces two new functions to PostGIS:  
>  > ST_Intersects(geometry, raster, band) and ST_Intersection(geometry,  
>  > raster, band).
>  >
>  > As its geometry/geometry sister, ST_Intersects(geometry, raster,  
>  > band) returns TRUE if the withvalue area of a raster or a raster  
>  > tile (nodata value are ignored) intersects a geometry and  
>  > ST_Intersection(geometry, raster, band) returns the geometry/value  
>  > set of geometries representing the intersection between the geometry  
>  >  and each polygonized group of pixel sharing a same value from the  
>  > raster and its associated value. Example:
>  >
>  > SELECT polyid,
>  >        (ST_Intersection(the_geom, rast)).geom,
>  >        (ST_Intersection(the_geom, rast)).val
>  > FROM my_polygons, srtm_tiled
>  > WHERE ST_Intersects(rast, the_geom)
>  >
>  > or, a bit more complex, but much faster and returning the same result:
>  >
>  > SELECT polyid, (gv).geom, (gv).val
>  > FROM (SELECT polyid, ST_Intersection(the_geom, rast, 1) AS gv
>  >      FROM my_polygons, srtm_tiled
>  >      WHERE ST_Intersects(rast, the_geom)) foo
>  >
>  > These functions works with any kind of geometry so you can intersect  
>  >  any road, river, polygons or point layer with your favorite  
>  > elevation or land cover raster of any resolution and any size. You  
>  > can also load any number of raster in the database with one command  
>  > line to constitute a unique table raster coverage of any shape (no  
>  > matter if your group of raster do not form a rectangular coverage).
>  >
>  > You will find a complete tutorial on how to use those two new  
>  > functions here:  
>  > http://trac.osgeo.org/postgis/wiki/WKTRasterTutorial01. A reference  
>  > is available here:  
>  > http://postgis.refractions.net/documentation/manual-svn/RT_reference.html  
>  > and chapter 13 of "PostGIS in Action" is also a very good  
>  > introduction to WKT Raster.
>  >
>  > Compilation and installation info are available in the project home  
>  > page: http://trac.osgeo.org/postgis/wiki/WKTRaster
>  >
>  > These features are the result of two years of collaboration between  
>  > many people and companies interested in bringing raster into  
>  > PostGIS. I would like to thanks particularly Steve Cumming who  
>  > initially made all this possible, Sandro Santilli who wrote the base  
>  >  code, Mateusz Loskot who wrote the Python loader, Jorge Arevalo who  
>  >  wrote the GDAL driver and ST_DumpAsPolygons(), Regina and Leo Obe  
>  > who are doing so many things and believed in the project from the  
>  > beginning by adding a chapter about WKT Raster in "PostGIS in  
>  > Action" and also David Zwarg who wrote most of the setter functions.
>  >
>  > This is the first step toward a first complete raster/vector  
>  > analysis and manipulation SQL API. We hope to make of PostGIS with  
>  > WKT Raster the most powerful and complete GIS analysis and  
>  > manipulation high level language ever (!!!). WKT Raster should  
>  > normally be totally integrated into PostGIS in PostGIS release 2.0.  
>  > Upcoming functions should include ST_Reclass, ST_Clip, ST_AsRaster,  
>  > ST_Resample.
>  >
>  > Let us know your need and your experience with WKT Raster.
>  >
>  > Thanks,
>  >
>  > Pierre Racine
>  >
>  > _______________________________________________
>  > gdal-dev mailing list
>  > gdal-dev at lists.osgeo.org
>  > http://lists.osgeo.org/mailman/listinfo/gdal-dev
>  >
>  
>  
>  
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