Hello Natalia:
(Returning to the list - perhaps someone else can help also)
On 11/05/2010 03:20 PM, Sofina Natalia wrote:
Am 04.11.2010 20:20, schrieb Micha Silver:
The "too many subclasses" is not necessarily an error. I believe that
it means one classification is too complicated, that is the spread of
pixel values is such that it can't create a signature for that class.
Did the process finish?
How did you make the training map? Are all the training areas with
the same category uniform? If you setup a training area that is too
large, with a broad mix of pixel values, then gensigset won't be able
to create unique signatures for each class.
HTH
--------------------------------------------------------------------------------------------
Hi, Micha!
I can't create a "sig-file" still... Below it is what I got after
starting the i.gensigset:
---------------------------------------------------------------------------------------------------------------
(Fri Nov 05 12:47:14 2010)
i.gensigset trainingmap=my...@image_classification
group=tr...@image_classification subgroup=train_sub
signaturefile=train_sig
No need to explicitly enter the mapset here. It shoud be enough to do:
i.gensigset trainingmap=my_cl group=train \
subgroup=train_sub signaturefile=train_sig
Finding training classes...
6 classes found
Reading raster maps...
Clustering class 1 (3324 pixels)...
Removed a singular subsignature number 5 (9 remain)
Removed a singular subsignature number 8 (8 remain)
Number of subclasses is 6
Clustering class 2 (1898 pixels)...
Removed a singular subsignature number 9 (9 remain)
Number of subclasses is 3
Clustering class 3 (2710 pixels)...
Number of subclasses is 10
Clustering class 4 (1347 pixels)...
Removed a singular subsignature number 10 (9 remain)
Removed a singular subsignature number 6 (8 remain)
Removed a singular subsignature number 2 (7 remain)
Number of subclasses is 6
Clustering class 5 (1024 pixels)...
Number of subclasses is 4
Clustering class 6 (2107 pixels)...
Number of subclasses is 1
So far this looks normal. You have a few thousand pixels in each
training area which should be enough.
unable to create signature file train_sig for subgroup train_sub of
group tr...@image_classification
Hmmm... What went wrong? One additional test below...
ERROR: Unable to create signature file <train_sig>
(Fri Nov 05 12:47:19 2010) Command finished (5 sec)
My training map I make so as it is described in your paper. I've tried
to create it with different sizes of the training areas. And the color
of the area I define using the function r.what.color.
I'm not sure what you mean here. Each training area should cover a
uniform feature in the landscape. Perhaps send the output of:
r.info my_cl
r.univar my_cl
I don't understand what is wrong... Which size should be a training
area? Does it depend on the number of pixels?
Thanks a lot,
Natalia
This mail was received via Mail-SeCure System.
--
Micha Silver
Arava Development Co. +972-52-3665918
http://www.surfaces.co.il
_______________________________________________
grass-user mailing list
grass-user@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/grass-user
