Basically (I use the old sub query style): SELECT ST_Union(ST_AsRaster(g.geom, ref.rast, '32BUI', g.id, 0))) rast FROM (SELECT ST_MakeEmptyRaster(1, 1, 0, 0, 1, -1, 0, 0, 0) AS rast) ref, mygeomtable g
however if your raster is high resolution ST_Union might be impractically slow. The other technique untill we get a faster ST_Union is to use ST_MapAlgebraFct and write your own function returning the geometry value from the intersection with the centroid of the pixel. See this example http://postgis.refractions.net/pipermail/postgis-users/2012-April/033875.html I agree this is relatively cumbersome but it should be much faster than ST_Union. Pierre > -----Original Message----- > From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users- > boun...@postgis.refractions.net] On Behalf Of Bborie Park > Sent: Tuesday, May 29, 2012 2:11 PM > To: postgis-users@postgis.refractions.net > Subject: Re: [postgis-users] Rasterize a vector > > On 05/29/2012 11:07 AM, Paolo Cavallini wrote: > > Il 29/05/2012 20:05, Pierre Racine ha scritto: > > > >> The most important is: At the end do you want all geometries to be burned > into the same raster or you want one raster per geometries? > > > > same raster - see gdal_rasterize for an example. > > thanks a lot. > > > > Run an ST_Union upon the set of output rasters. > > -bborie > > -- > Bborie Park > Programmer > Center for Vectorborne Diseases > UC Davis > 530-752-8380 > bkp...@ucdavis.edu > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
