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 >> '0100000100000000000088C340000000000088C3C03FF0F16F910F29C1F38C064BB32D244100000000000000000000000000000000C67D00000A000A0045FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF0100FFFFFFFFFFFFFFFFFFFF0300FFFF040005000600FFFFFFFFFFFF0C000D000E000F00100011001200FFFFFFFFFFFF180019001A001B001C001D001E00FFFFFFFFFFFF2400250026002700280029002A00FFFFFFFFFFFF3400350036003700380039003A00FFFFFFFF4B004C004D004E004F00500051005200FFFFFFFF6A006B006C006D006E006F0070007100FFFFFFFF8F009000910092009300940095009600FFFFFFFFB500B600B700B800B900BA00BB00BC00'::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 > > -- 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
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