ST_Union works on overlapping rasters as well but maybe you have to provide two 3 bands rasters. If your rasters are tiled, you also have to GROUP BY tiles having the same alignment:
GROUP BY ST_UpperleftX(rast), ST_UpperleftY(rast) ST_MapAlgebra() should work also. The expression should be equal to the raster with values and the extenttype to the 256x256 pixel one. They shoulp overlap. Pierre > -----Original Message----- > From: postgis-users [mailto:postgis-users-boun...@lists.osgeo.org] On Behalf > Of Alexander Rumanovsk > Sent: Wednesday, August 10, 2016 12:40 PM > To: postgis-users@lists.osgeo.org > Subject: [postgis-users] Merge rasters with multiple bands > > Hello all, > > I'm trying to merge a raster with 3 bands to an empty raster. The empty > raster is > created with the query bellow: > > ST_AddBand(ST_MakeEmptyRaster(256,256,0,0,1), '8BUI'::text,200) > > > This empty raster is larger than the filled one (which is 100x100). I just > need to > create a raster of 256x256 with the original raster (100x100) information and > the rest filled with empty information. > My first idea was to use ST_Union, but found out it just merges tiles, > instead of > rasters. > Anyone have an idea how can I do that? > > thanks in advance > Rumanovsk _______________________________________________ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/postgis-users
