I am using GDAL 1.9.2, yep ST_PixelAsPolygons() works fine,<br><br>Jean<br><br><div class="gmail_quote">2013/6/6 dustymugs <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">What version of GDAL are you using? ST_DumpAsPolygons() uses GDAL for<br>
processing. I notice that ST_PixelAsPolygons() works correctly...<br>
<span class="HOEnZb"><font color="#888888"><br>
-bborie<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
On 06/06/2013 01:04 PM, Jean Marchal wrote:<br>
> Bborie,<br>
><br>
> I used ST_Value to prove that the value for pixel with coordinates (8,2)<br>
> does exist. I did not mention it but adjacent pixels contains different<br>
> values (see reproducible example).<br>
><br>
> Jean<br>
><br>
> 2013/6/6 Bborie Park <<a href="mailto:dustymugs@gmail.com">dustymugs@gmail.com</a>><br>
><br>
>> ST_Value and ST_DumpAsPolygons do very different things. ST_Value gets a<br>
>> value for a specific pixel while ST_DumpAsPolygons() dumps values by<br>
>> merging pixels with same value in an area.<br>
>><br>
>> -bborie<br>
>><br>
>><br>
>> On Thu, Jun 6, 2013 at 12:38 PM, Jean Marchal <<a href="mailto:jean.d.marchal@gmail.com">jean.d.marchal@gmail.com</a>>wrote:<br>
>><br>
>>> 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),<br>
>>> ST_BandPixelType(rast)<br>
>>> FROM (SELECT '<br>
>>> 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raster<br>


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


>>> rast) foo<br>
>>><br>
>>> Is this a bug or I am doing something wrong ?<br>
>>><br>
>>> Thanks,<br>
>>><br>
>>> Jean<br>
>>><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<br>
>>><br>
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>>><br>
>>><br>
>><br>
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><br>
><br>
><br>
><br>
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</div></div></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<br>