[GRASS-user] Viewing ecw files

Hamish hamish_nospam at yahoo.com
Thu Feb 15 18:03:41 EST 2007


> > Nicholas wrote:
> > >> It would be really nice if GRASS had a wavelet based scheme for
> > >> imagery, but that would require significant development and many
> > >> of us don't have the spare time available.  At the moment,
> > >> Hamish's suggestion is about the best that can be done.  GRASS
> > >> cannot handle such large datasets with efficiency.
> > >>
> > >> ECW is a wonderful format.  It is hard to beat the compression
> > >> and speed of scale change.
Brad:
> I did notice that there is an add-on r.wavelet module, but I have not
> used it.  The backend library seems to be license-free and GPL, IIRC.
> 
> Wavelets for GRASS as an imagery format is "pie in the sky". :-\ 
> There are too many other issues that need attention at the moment.


maybe a r.external module could read/write GDAL formats (JPEG2000,
ECW, MrSID..) as v.external does for OGR formats?

A simple script using gdal_translate to extract and import the current
region (read-only) could be written in a few minutes. (r.in.gdal flag?)

FWIW, ER Mapper's ECW SDK page states "Free unlimited compression use in
GPL style software".  http://www.ermapper.com/ProductView.aspx?t=28

Also that page claims that there is a lossless version available- which
is a requirement for us. 


Hamish




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