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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>You don’t need the function ST_Band…<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>You need to be able to do something like:<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>SELECT ST_Max(r), ST_Min(r) FROM ST_Clip(raster, mypolygon)) r<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>ST_Clip() is planned but ST_Min() and ST_Max() are not but
should definitely be welcome.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Pierre<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Rainer Zaiss
[mailto:Rainer.Zaiss@ird.fr] <br>
<b>Sent:</b> 9 février 2010 08:54<br>
<b>To:</b> Pierre Racine<br>
<b>Subject:</b> RE: [postgis-users] WKTraster pixel value<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>Hi Pierre,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>Thank you very much for your reply. I just want to calculate the
Min and Max value of my raster inside an area of interest. The raster file is a
DEM single band raster the area of interest is a polygon. I guess I need the
function </span><span lang=EN-GB style='font-size:10.0pt;font-family:
"Courier New"'>ST_Band(raster, band)). I will wait I while until the function
will be implemented.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Courier New"'>Thank
you</span><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'><o:p> </o:p></span></p>
<div>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>Rainer Zaiss</span><span lang=FR style='color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>Secteur Cartographie</span><span lang=FR style='color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>IRD - Centre de recherche d'Île-de-France</span><span lang=FR
style='color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>32, avenue Henri Varagnat</span><span lang=FR style='color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>93143 Bondy cedex</span><span lang=FR style='color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>Tél: 01 48 02 55 06</span><span lang=FR style='color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'>Fax: 01 48 02 79 35</span><span lang=FR style='color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:navy'><a href="mailto:RaRainer.Zaiss@ird.fr">Rainer.Zaiss@ird.fr</a></span><span
lang=FR style='color:navy'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='color:navy'><a
href="http://www.bondy.ird.fr/carto"><span style='font-size:10.0pt;font-family:
"Arial","sans-serif"'>http://www.bondy.ird.fr/carto</span></a></span><span
lang=FR><o:p></o:p></span></p>
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<div class=MsoNormal align=center style='text-align:center'><span lang=FR>
<hr size=3 width="100%" align=center>
</span></div>
<p class=MsoNormal><b><span lang=FR style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>De :</span></b><span
lang=FR style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Pierre
Racine [mailto:Pierre.Racine@sbf.ulaval.ca] <br>
<b>Envoyé :</b> mardi 9 février 2010 14:19<br>
<b>À :</b> Rainer.Zaiss@ird.fr; PostGIS Users Discussion<br>
<b>Objet :</b> RE: [postgis-users] WKTraster pixel value</span><span
lang=FR><o:p></o:p></span></p>
</div>
<p class=MsoNormal><span lang=FR><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Rainer,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>There is a difference between accessing a whole band of a
multiband raster and access a single pixel value.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The ST_Band(rast raster, band integer) function (not yet
implemented) will return a whole band (i.e. an object of type raster).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The ST_Value(rast raster, band integer, x integer, y integer)
function (implemented but not yet documented) returns the value of a single
pixel expressed as a float point value. <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Pierre<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<div>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <b>On Behalf Of </b>Rainer
Zaiss<br>
<b>Sent:</b> 9 février 2010 04:10<br>
<b>To:</b> postgis-users@postgis.refractions.net<br>
<b>Subject:</b> [postgis-users] WKTraster pixel value<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'>Dear list,<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'>I just played around with
WKTraster. I just want to have a confirmation that the function to access the
pixel values is not yet implied (ST_Band(raster, band)) ?<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'>Thank you very much for your
help<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Courier New"'>Rainer</span><span
lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif"'><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=FR><o:p> </o:p></span></p>
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