Bborie,<br><br>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).<br><br>Jean <br><br><div class="gmail_quote">

2013/6/6 Bborie Park <span dir="ltr"><<a href="mailto:dustymugs@gmail.com" target="_blank">dustymugs@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">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.<div>


<br></div><div>
-bborie</div></div><div class="gmail_extra"><br><br><div class="gmail_quote"><div><div>On Thu, Jun 6, 2013 at 12:38 PM, Jean Marchal <span dir="ltr"><<a href="mailto:jean.d.marchal@gmail.com" target="_blank">jean.d.marchal@gmail.com</a>></span> wrote:<br>



</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div>Dear List,<br><br>value's number 4 in this raster come out with ST_Value:<br><br>
SELECT ST_Value(rast, 1, 8, 2), ST_BandnoDataValue(rast), ST_BandPixelType(rast)<br>
FROM (SELECT '<div>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'::raster rast) foo<br>








<br>but not with ST_DumpAsPolygons:<br><br>SELECT (ST_DumpAsPolygons(rast)).val<br>FROM (SELECT '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'::raster rast) foo<br>








<br>Is this a bug or I am doing something wrong ?<br><br>Thanks,<br><br>Jean<div><div><br><span><font color="#888888">-- <br>Jean Marchal<br><br>Etudiant au doctorat / PHD student<br>Université Laval - Pavillon Abitibi-Price<br>





Faculté de foresterie, de géographie et de géomatique<br>2405, rue de la Terrasse<br>Québec (Québec) G1V 0A6<br></font></span></div></div>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Jean Marchal<br><br>Etudiant au doctorat / PHD student<br>Université Laval - Pavillon Abitibi-Price<br>Faculté de foresterie, de géographie et de géomatique<br>2405, rue de la Terrasse<br>


Québec (Québec) G1V 0A6