[GRASS5] Training sites and classification

How can I define the training sites in GRASS? I tried using i.class but I'm not very clear on how to deal with it.
In fact I'm a bit confused about the classification processes in GRASS, as the documentation is not very clear to me. Can anyone give some hints on this?

Thanks,

--
Gualter Barbas Baptista
gualter@gaia.org.pt ICQ# 8106393 jabber.org: gandhiano

GAIA - Grupo de Acção e Intervenção Ambiental
gaia@gaia.org.pt
Portugal

On Sat, Oct 19, 2002 at 06:39:06PM +0100, Gualter Barbas Baptista wrote:

How can I define the training sites in GRASS? I tried using i.class but
I'm not very clear on how to deal with it.
In fact I'm a bit confused about the classification processes in GRASS,
as the documentation is not very clear to me. Can anyone give some hints
on this?

Hi,

did you look at
http://grass.itc.it/gdp/imagery/imagery.ps.gz
or
http://grass.itc.it/gdp/index.html#tutorials
?

Following choices currently exist in GRASS 5 for image classification:
(see above books and tutorials)

               |radiometric, | radiometric, | radio- and geometric,
               |unsupervised | supervised | supervised
---------------+-------------+-------------------------+---------------------
Training areas | -- | a) i.class (in monitor) | a) r.digit
               | | b) r.digit; | b) v.digit/v.to.rast
               | | v.digit/v.to.rast |
               | | c) existing map | c) existing map
---------------+-------------+-------------------------+---------------------
Statistical | i.cluster | a) i.class (in monitor) | i.gensigset
preprocessing | | b) i.gensig (from map) |
---------------+-------------+-------------------------+---------------------
Computation | i.maxlik | i.maxlik | i.smap
---------------+-------------+-------------------------+---------------------

Cheers,

Markus Neteler