[postgis-devel] [PostGIS] #640: ST_SetPixelSize behaving unpredictably

PostGIS trac at osgeo.org
Fri Oct 22 21:42:37 PDT 2010


#640: ST_SetPixelSize behaving unpredictably
----------------------------+-----------------------------------------------
 Reporter:  robe            |       Owner:  pracine      
     Type:  defect          |      Status:  new          
 Priority:  medium          |   Milestone:  PostGIS 2.0.0
Component:  postgis raster  |     Version:  trunk        
 Keywords:                  |  
----------------------------+-----------------------------------------------
 Okay perhaps it is my misunderstanding.

 I have 2 elephants -- one I brought in whole and one I chopped into
 pieces.


 {{{
 -- we let this one live
 python gdal2raster.py -r pele.png -I -t ch13.pele -o pele.sql

 - we sacrifice this one
 python gdal2raster.py -r pele.png -I -k 50x50 -t ch13.pele_chunked -o
 pele_chunked.sql

 }}}

 Both come in upside down, which I assume is becasue I imported with gdal
 1.6.  No problem.

 -- run this command

 {{{
 UPDATE ch13.pele SET rast = ST_SetPixelSize(rast,1,-1);
 UPDATE ch13.pele_chunked SET rast = ST_SetPixelSize(rast,1,-1);
 }}}

 The single row whole one flips over correctly to line up with the image as
 I expect.  The second one just shifts down one row.

 I would have expected the sacrificed elephant to also line up with the
 image after flipping.

 See attached files.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/640>
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