[GRASS-user] Apply a segmentation to derive objects

[Markus Neteler]

On Mon, Jan 18, 2010 at 6:30 PM, Nikos Dumakis <nikosdu1980 at gmail.com> wrote:
> Greetings all
> I've been following GRASS-user discussion related with pos-classigfication,
> classification, aggregation and so on. But, while I was readingh those
> emails I figured that I will need to perform, before classification, an
> image segmentation to derive objects.

You don't need to perform a segmentation before doing classification but
i.smap is doing it in a combined way.

> Can anyone give me a clue abvout that because in GRASS book, I only founded
> Image segmentation related with processing large quantities of vectorial
> data (DEM's).

(DEMs are raster data)

What you need to do is to prepare the statistics with i.gensigset. See
"radiometric & geometric  supervised" in

http://grass.osgeo.org/wiki/Image_classification

(The book is explaining that as well)

Hope this helps,
Markus