[GRASS5] r.in.gdal updates?

Glynn Clements glynn.clements at virgin.net
Sun Mar 2 13:53:56 EST 2003


Glynn Clements wrote:

> > I would like to ask if a developer is willing to update r.in.gdal
> > (Frank Warmerdam told me that he won't do that at time):
> > 
> > Outstanding
> >  - fix the grey color tables issue for RGB maps
> 
> The main problem here is determining the overall range of the data,
> i.e. which values correspond to black and white. Black is almost
> certain to be 0, but determining white is more difficult. Usually it's
> ((1<<bit_depth)-1), but you need to know what bit_depth is.

The upshot of a private conversation with Frank is that GDAL doesn't
make this information available. Consequently, you would need to use
heuristics to determine the bit depth (and hope that the image isn't
too dark).

-- 
Glynn Clements <glynn.clements at virgin.net>




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