Hi Carl, I may be reading too much into your message, but my spidey sense tells me you might be using ST_Value inside a loop to get values to put in an equation (or to evaluate thresholds), thereby constructing an output raster. If this is the case, a more efficient way to proceed may be to use ST_MapAlgebra (for equations), or ST_Reclass (for thresholds). No muss no fuss.
Hope that helps, Bryce From: [email protected] [mailto:[email protected]] On Behalf Of Albury, Carl -FS Sent: Tuesday, April 21, 2015 10:18 AM To: [email protected] Subject: Re: [postgis-users] ST_Value on tiled raster Hi I'm new to PostGIS so please bear with me. I'm working with MODIS data that I tiled using the auto tile switch in raster2pgsql resulting in 13250 82x94 tiles. When I try to query for pixel values using ST_Value, such as: SELECT ST_Value(rast, 2, 1,1) -- multiband raster FROM MODIS_test; I get a value for each tile, not for each pixel (I assume the value is for the first pixel in the tile?). If I want to query each pixel do I need to loop through each tile and have a sub loop for each pixel in that tile? If so I can't figure out the syntax to designate the tiles vs pixels. Thanks very much, Carl
_______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
