Need help converting mrSid {Scanned}

[Gregor Mosheh]

> Yes I've downloaded that file, but it seems as tho the output file will be to
> large
> The input file is about 1G (I have one that is a tad over 3G).
> It doesn't have to be a GeoTiff, but does need to be something HostGIS can
> understand.
> Any thoughts on that?

Yeah. TIFF has a size limit of 2 GB. If your MrSID is 1 GB, then it 
probably has some 10 GB if it were converted to TIFF. Look at that width 
and height, and figure out what dimensions would correspond to just 
under 2 GB, then use the -srcwin flag to extract a small part of the 
file, several times.

Example:
gdal_translate -of GTiff -srcwin      0 0 20000 21500 co.sid co1.tif
gdal_translate -of GTiff -srcwin  20000 0 20000 21500 co.sid co1.tif
gdal_translate -of GTiff -srcwin  40000 0 20000 21500 co.sid co1.tif
gdal_translate -of GTiff -srcwin  60000 0 20000 21500 co.sid co1.tif
gdal_translate -of GTiff -srcwin  80000 0 20000 21500 co.sid co1.tif
gdal_translate -of GTiff -srcwin 100000 0 23859 21500 co.sid co1.tif
and so on

Thus, you'll have 12 TIFFs of about 900 MB GB apiece. Then you'd make a 
tileindex to mosaic them back together. It's a bit roundabout, but 
that's life with a proprietary image format that doesn't even have a 
driver for Linux.

-- 
Gregor Mosheh / Greg Allensworth
System Administrator, HostGIS cartographic development & hosting services
http://www.HostGIS.com/

"Remember that no one cares if you can back up,
  only if you can restore." - AMANDA