[GRASS-dev] Re: [GRASSGUI] Adding a Raster Group as layer

Hamish hamish_nospam at yahoo.com
Wed May 23 03:23:30 EDT 2007

> Yann wrote:
> > After importing a multispectral image with r.in.gdal, a group is
> > created holding all these layers.

> I don't follow you on this. What kind of group? AFAIK, r.in.gdal just
> creates a set of separate raster files with identical prefixed names.
> Does it build an image group?

Yes, r.in.gdal puts all imported bands into a group. "g.list group"
Get map names in the group with "i.group -g $GROUPNAME". (or "-l")

> > Could we have a button that would show/select/load any existing
> > group in the GUI (it could have a tree inside for all the bands
> > available).
> > 
> > Once loaded we could select one or any combination of 3 bands for
> > display.
> Putting the maps in separate layers would simply overlay one on top of
> the other, not recombine them into an RGB image again. This would have
> to take place within d.rgb.
> Following your idea, an enhanced d.rgb would be able to load a group,
> in addtion to just any individual layer, making layer selection more
> convenient for bands of a multiband image. I'd add that it should also
> have a couple of options for doing automatic equalization stretches
> (linear, log, and gaussian if I want to imagine a really nice module)
> on the bands before it displays them.

"d.rgb group=" or rgbhis.tcl browse button.

The group list is not ordered, so you would have to assume that Red was
first, Green second, and Blue third, and ignore any other bands.
Maybe ok for hinting map names in rgbhis.tcl.


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