<br><font size=2 face="sans-serif">All,</font>
<br>
<br><font size=2 face="sans-serif">I have a mrsid file: </font>
<br><font size=2 face="sans-serif"> sf.sid</font>
<br><font size=2 face="sans-serif"> 2,119,161,888 bytes</font>
<br><font size=2 face="sans-serif">My end goal is to create an image pyramid
with geotiffs from this mrsid file for use with the geoserver image mosaic
plugin.</font>
<br><font size=2 face="sans-serif">To that end I am trying to subset this
mrsid file with gdal_translate.</font>
<br><font size=2 face="sans-serif">It *seems* that I can use gdal_translate
successfully on a small area but not on relatively large area.</font>
<br>
<br><font size=2 face="sans-serif">This command appears to work properly
for a relatively small area (units=feet, projection=epsg:2227)</font>
<br><font size=2 face="sans-serif"> gdal_translate -of HFA
-projwin 6001765 2096567 6003198 2094764 sf.sid test1.img</font>
<br><font size=2 face="sans-serif">By "appear" I mean when I
*look* at the output using ArcMap, they are georeferenced properly and
the image appears (qualitatively) to be the same as the original.</font>
<br><font size=2 face="sans-serif">gdalinfo for test1.img snippets:</font>
<br><font size=2 face="sans-serif"> Size is 2866, 3606</font>
<br><font size=2 face="sans-serif"> Origin = (6001764.559999999600000,2096567.399999999900000)</font>
<br>
<br><font size=2 face="sans-serif">Now, here is the command for the larger
area:</font>
<br><font size=2 face="sans-serif"> gdal_translate -of HFA
-projwin 5978648 2131842 6025550 2085070 mrsid\sf.sid pict2004.img</font>
<br><font size=2 face="sans-serif">I see no error and the resulting files
include:</font>
<br><font size=2 face="sans-serif"> 26,337,579,229 pict2004.ige</font>
<br><font size=2 face="sans-serif"> 22,078 pict2004.img</font>
<br><font size=2 face="sans-serif"> 11,303 pict2004.img.aux.xml</font>
<br><font size=2 face="sans-serif"> 11,972 pict2004.img.info</font>
<br><font size=2 face="sans-serif">gdalinfo for pict2004.img snippets:</font>
<br><font size=2 face="sans-serif"> Size is 93804, 93544</font>
<br><font size=2 face="sans-serif"> Origin = (5978647.559999999600000,2131842.399999999900000)</font>
<br><font size=2 face="sans-serif">Note the size.</font>
<br>
<br><font size=2 face="sans-serif">Since this file size from the previous
step is unwieldy for visual inspection, I subset again just to do a visual
inspection:</font>
<br><font size=2 face="sans-serif"> gdal_translate -of HFA
-projwin 6001765 2096567 6003198 2094764 pict2004.img test2.img</font>
<br><font size=2 face="sans-serif">gdalinfo for test2.img snippets:</font>
<br><font size=2 face="sans-serif"> Size is 2866, 3606</font>
<br><font size=2 face="sans-serif"> Origin = (6001764.559999999600000,2096567.399999999900000)</font>
<br><font size=2 face="sans-serif">When I *look* at test2.img I see the
following problems:</font>
<br><font size=2 face="sans-serif">1) georeferecning is incorrect</font>
<br><font size=2 face="sans-serif">2) aspect ratio is incorrect</font>
<br><font size=2 face="sans-serif">3) scale is incorrect</font>
<br>
<br><font size=2 face="sans-serif">I am obviously missing something - can
someone please tell me what it is?</font>
<br>
<br><font size=2 face="sans-serif">Thanks</font>
<br><font size=2 face="sans-serif">Paul</font>
<br>