[gdal-dev] GTiff optimisation

Yves Jacolin yjacolin at free.fr
Thu Sep 1 04:39:50 EDT 2011

Le mercredi 31 août 2011 16:45:09, Jean-Claude Repetto a écrit :
> Le 31/08/2011 14:13, Yves Jacolin a écrit :
> > Another question: I have 2 000 ECW files (40 Mo each), 49 ECW files (1 Go
> > each) and 2 ECW files (2 Go each). I worked first on 2 Go ECW file, it
> > takes around 1 day to assign the projection information in the files.
> > 
> > Do you think this is normal? How can I improve this?
> Since you are using Linux, you may be interested in a tool I wrote a few
> years ago :
> http://jrepetto.free.fr/ecwhed/
> You can compile it manually by a command such as :
> g++ -o ecwhed -l pthread  ecwhed.cpp /usr/lib64/libecwj2.a
> ( The standard procedure ./configure; make; make install is not working
> anymore. If you know the autotools, may be you can fix it).
> Jean-Claude
Thanks Jean-Claude for your reply as I could build your app. Here some 

* original data show correct header with projection information
* data made from gdal show "raw" as DATUM and PROJ using ecwhed utilities:
>Datum = RAW
>Projection = RAW

What I don't understand is that QGIS or GDAL don't find it from the original 
data. Is it possible that there is some ECW specific projection information as 
ESRI one? I saw an ecw_cs.wkt file in the gdal data dir.

Any idea?


Yves Jacolin


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