[GRASS-dev] About signature files.

GRASS GIS GRASS GIS developer
1

Hi coworkers

I'm working with grass62. Now I'm trying to develop a code to classify
MODIS images. I have been using i.cluster, but this code perform an
unsupervised classification (in conjunction with i.maxlik). I have three
categories built with v.digit, then I need the signature file for this
training pixels like input to i.maxlik. Someone have developed an
"i.signature" code, with a categorized map like input, and the signature
file like output?

Thanks to all.

Juan Diego

2

Juan Diego Giraldo Osorio wrote on 09/10/2007 05:17 PM:

Hi coworkers

I'm working with grass62. Now I'm trying to develop a code to classify
MODIS images. I have been using i.cluster, but this code perform an
unsupervised classification (in conjunction with i.maxlik). I have three
categories built with v.digit, then I need the signature file for this
training pixels like input to i.maxlik. Someone have developed an
"i.signature" code, with a categorized map like input, and the signature
file like output?
  

It is there: i.gensig. Here the overview:

Classification methods in GRASS (table best seen with courier font):

              |radiometric,| radiometric, supervised | radio-
and geo-
              |unsupervised| |metric,
supervised
--------------+------------+---------------------------------+------------------
Preprocessing | i.cluster |i.class (monitor) i.gensig
(maps)|i.gensigset (maps)
--------------+------------+---------------------------------+------------------
Computation | i.maxlik | i.maxlik i.maxlik | i.smap

Hope this helps,
Markus

------------------
ITC -> dall'1 marzo 2007 Fondazione Bruno Kessler
ITC -> since 1 March 2007 Fondazione Bruno Kessler
------------------

3

Markus Neteler wrote on 09/10/2007 06:18 PM:

Juan Diego Giraldo Osorio wrote on 09/10/2007 05:17 PM:
  

Hi coworkers

I'm working with grass62. Now I'm trying to develop a code to classify
MODIS images. I have been using i.cluster, but this code perform an
unsupervised classification (in conjunction with i.maxlik). I have three
categories built with v.digit, then I need the signature file for this
training pixels like input to i.maxlik. Someone have developed an
"i.signature" code, with a categorized map like input, and the signature
file like output?
  

It is there: i.gensig. Here the overview:

Classification methods in GRASS (table best seen with courier font):

OK, the table didn't survive the formatting.
Just have a look here:

g.manual imageryintro
or
http://grass.itc.it/grass63/manuals/html63_user/imageryintro.html
-> Image classification

Markus

------------------
ITC -> dall'1 marzo 2007 Fondazione Bruno Kessler
ITC -> since 1 March 2007 Fondazione Bruno Kessler
------------------