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.
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).
Thanks for your help
Berst regards,
Nikos
On Mon, Jan 18, 2010 at 6:30 PM, Nikos Dumakis <nikosdu1980@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
You are absolutely right 
My mistake. SMAP is a segmentation algorithm. But my idea was not to use SMAP as a classification but use a Segmentation process and only then a Supervides Classification. Or if Use SMAP I’m doing both things in this order?
Thanks Markus
Nikos
On Mon, Jan 18, 2010 at 11:22 PM, Markus Neteler <neteler@osgeo.org> wrote:
On Mon, Jan 18, 2010 at 6:30 PM, Nikos Dumakis <nikosdu1980@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” inhttp://grass.osgeo.org/wiki/Image_classification
(The book is explaining that as well)
Hope this helps,
Markus
You are absolutely right My mistake. SMAP is a segmentation algorithm. But my idea was not to use SMAP as a classification but use a Segmentation process and only then a Supervides Classification. Or if Use SMAP I’m doing both things in this order?
Thanks Markus
Nikos
On Mon, Jan 18, 2010 at 11:22 PM, Markus Neteler <neteler@osgeo.org> wrote:
On Mon, Jan 18, 2010 at 6:30 PM, Nikos Dumakis <nikosdu1980@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” inhttp://grass.osgeo.org/wiki/Image_classification
(The book is explaining that as well)
Hope this helps,
Markus
Hi
Regarsding segmentation, has anyone implemented a method to segment an image in a unsupervised way? (i.smap is supervised).
Or anyone developed some method to do image segmentation?
Thanks
Nikos
On Mon, Jan 18, 2010 at 11:22 PM, Markus Neteler <neteler@osgeo.org> wrote:
On Mon, Jan 18, 2010 at 6:30 PM, Nikos Dumakis <nikosdu1980@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” inhttp://grass.osgeo.org/wiki/Image_classification
(The book is explaining that as well)
Hope this helps,
Markus