[GRASS5] Re: d.his r.his question

Markus Neteler neteler at itc.it
Wed Dec 12 10:24:54 EST 2001


On Wed, Dec 12, 2001 at 03:04:19PM +0000, Glynn Clements wrote:
> 
> Markus Neteler wrote:
> 
> > > I am actaully writing with a question about d.his (and r.his). In the
> > > past I used a modified version of d.his to create color shaded relief
> > > maps. In other words I fused a color raster (h_map) with a grey
> > > sun-illuminated raster (i_map).  The new r.his seems to be (correctly)
> > > designed for imagery.
> 
> Treating colour images as a single raster layer with R*G*B distinct
> categories is something of a kludge. In the absence of vector-valued
> cell maps (i.e. band-interleaved-by-pixel), the next best thing (IMHO)
> is separate R,G,B maps (effectively band-sequential).
> 
> I'm having second thoughts about whether r.his and r.composite should
> have separate arguments for each channel, though. It might be better
> to just have input=/output= and require that the bands are called
> foo.r, foo.g and foo.b.

... that's  a good suggestions which reduces typing efforts.
eventually just:

 input=name [prefix=name]

if !prefix
 prefix=input 

[...]

Markus



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