Egge-Jan, That is an intriguing question with no clean/simple solution. The fastest approach may be to call ST_Reclass() to create a 1BB mask based upon that value and the pass the resulting raster to ST_PixelAsPolygons() which will give you what you want.
Yes, the above is a round-about way to do this. This is something I'll (ST_PixelofValue?) see about adding for PostGIS 2.1. -bborie On 06/25/2012 01:16 PM, e.j.h.polle wrote: > Hi, > > OK - with ST_SummaryStats it is easy to retrieve the highest value in the > raster, but then I only have this value. Now I want to retrieve > (information about) the cell/pixel having this value, to be able to > visualize the highest point on the map. My original query (see first post) > does give me this information (after 45 seconds...). > > How would I go about to get hold of the pixel with the highest value, > knowing this value? > > Cheers, > > Egge-Jan > > On Sunday, June 24, 2012 8:47:58 PM UTC+1, DavidRA wrote: >> >> Why don't you use ST_SummaryStats instead ST_Value? That way you can get >> easily any basic stat, included the maximum value of the raster. It would >> be >> something like: >> >> SELECT (ST_SummaryStats(rast)).max FROM raster_table; >> >> -- >> View this message in context: >> http://postgis.17.n6.nabble.com/Finding-highest-cell-value-in-raster-using-ST-Value-tp4998545p4998554.html >> >> Sent from the PostGIS - User mailing list archive at Nabble.com. >> _______________________________________________ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > > On Sunday, June 24, 2012 8:47:58 PM UTC+1, DavidRA wrote: >> >> Why don't you use ST_SummaryStats instead ST_Value? That way you can get >> easily any basic stat, included the maximum value of the raster. It would >> be >> something like: >> >> SELECT (ST_SummaryStats(rast)).max FROM raster_table; >> >> -- >> View this message in context: >> http://postgis.17.n6.nabble.com/Finding-highest-cell-value-in-raster-using-ST-Value-tp4998545p4998554.html >> >> Sent from the PostGIS - User mailing list archive at Nabble.com. >> _______________________________________________ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > > On Sunday, June 24, 2012 8:47:58 PM UTC+1, DavidRA wrote: >> >> Why don't you use ST_SummaryStats instead ST_Value? That way you can get >> easily any basic stat, included the maximum value of the raster. It would >> be >> something like: >> >> SELECT (ST_SummaryStats(rast)).max FROM raster_table; >> >> -- >> View this message in context: >> http://postgis.17.n6.nabble.com/Finding-highest-cell-value-in-raster-using-ST-Value-tp4998545p4998554.html >> >> Sent from the PostGIS - User mailing list archive at Nabble.com. >> _______________________________________________ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > > > > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users -- Bborie Park Programmer Center for Vectorborne Diseases UC Davis 530-752-8380 bkp...@ucdavis.edu _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users