> Hi, I need to develop a tool that is able to connect with PostGIS and extract > the cell values from a raster stored in it creating a matrix with them. It > could be done with queries launched from that tool, using ST_Value(), for > each cell, but the number of queries would be huge.
You would better be creating a polygon encompassing the pixels you want and ST_Clip the raster to this polygon and then get all the values with (ST_PixelAsPolygons()).val, (ST_PixelAsPolygons()).x, (ST_PixelAsPolygons()).y But could you explain what you intent to do with the values of the matrix? Maybe there is a simpler way to do it in SQL... Maybe just adding a parameter to ST_Neighborhood stating that the neighbourhood should be a square instead of a circle would also do what you want. Bborie? Pierre _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
