What version of GDAL are you using? ST_DumpAsPolygons() uses GDAL for processing. I notice that ST_PixelAsPolygons() works correctly...
-bborie On 06/06/2013 01:04 PM, Jean Marchal wrote: > Bborie, > > I used ST_Value to prove that the value for pixel with coordinates (8,2) > does exist. I did not mention it but adjacent pixels contains different > values (see reproducible example). > > Jean > > 2013/6/6 Bborie Park <[email protected]> > >> ST_Value and ST_DumpAsPolygons do very different things. ST_Value gets a >> value for a specific pixel while ST_DumpAsPolygons() dumps values by >> merging pixels with same value in an area. >> >> -bborie >> >> >> On Thu, Jun 6, 2013 at 12:38 PM, Jean Marchal >> <[email protected]>wrote: >> >>> Dear List, >>> >>> value's number 4 in this raster come out with ST_Value: >>> >>> SELECT ST_Value(rast, 1, 8, 2), ST_BandnoDataValue(rast), >>> ST_BandPixelType(rast) >>> FROM (SELECT ' >>> 0100000100000000000088C340000000000088C3C03FF0F16F910F29C1F38C064BB32D244100000000000000000000000000000000C67D00000A000A0045FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF0100FFFFFFFFFFFFFFFFFFFF0300FFFF040005000600FFFFFFFFFFFF0C000D000E000F00100011001200FFFFFFFFFFFF180019001A001B001C001D001E00FFFFFFFFFFFF2400250026002700280029002A00FFFFFFFFFFFF3400350036003700380039003A00FFFFFFFF4B004C004D004E004F00500051005200FFFFFFFF6A006B006C006D006E006F0070007100FFFFFFFF8F009000910092009300940095009600FFFFFFFFB500B600B700B800B900BA00BB00BC00'::raster >>> rast) foo >>> >>> but not with ST_DumpAsPolygons: >>> >>> SELECT (ST_DumpAsPolygons(rast)).val >>> FROM (SELECT >>> '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'::raster >>> rast) foo >>> >>> Is this a bug or I am doing something wrong ? >>> >>> Thanks, >>> >>> Jean >>> >>> -- >>> Jean Marchal >>> >>> Etudiant au doctorat / PHD student >>> Université Laval - Pavillon Abitibi-Price >>> Faculté de foresterie, de géographie et de géomatique >>> 2405, rue de la Terrasse >>> Québec (Québec) G1V 0A6 >>> >>> _______________________________________________ >>> postgis-users mailing list >>> [email protected] >>> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >>> >>> >> >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >> >> > > > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
