Got permission to show the actual data: <http://osgeo-org.1560.x6.nabble.com/file/t381880/RUklfeY.png> (left side is what the data should look like, red is what the data looks like after calling the difference operation). -- Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html