[gdal-dev] Kakadu JP2 Output Overviews possible?
even.rouault at mines-paris.org
Thu Jul 12 02:17:03 PDT 2012
Selon "Zermeno, Robert J CIV NAVAIR, 472100D" <robert.zermeno at navy.mil>:
> GDAL Community,
> I noticed GDAL has a utility program gdaladdo which embeds new overviews to a
> supplied file. Does gdal have a utility program that allows me to extract
> overviews to a file?
Yes, it is a debug utility, called dumpoverviews, that is not compiled by
default. You will have to download GDAL sources, compile them, and then go to
the "apps" directory and : make dumpoverviews (Linux/Unix) or nmake /f
makefile.vc dumpoverviews.exe (Windows)
The source http://trac.osgeo.org/gdal/browser/trunk/gdal/apps/dumpoverviews.cpp
will answer all your questions.
I'd note that JP2 is a bit special. The full resolution image and the overviews
are mixed in the JP2 datastream. The choice of overviews levels exposed by GDAL
is rather arbitrary.
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