[GRASS-user] Semi-automatic classification with GRASS modules

[Giuseppe Cillis]

Thanks you for the answers!
The aerial photos classification is a common problem. In particular when
there is a need to classify small elements.
I have alway done a manual classification but now I need to eleborate many
photos to distinguish the forest from the agricultural areas. So, I will
try with different modules and, if doesn't work, I will use GRASS direclty.

2018-07-05 8:17 GMT+02:00 Nikos Alexandris <nik at nikosalexandris.net>:

> Michele Zurlo:
>
> [..]
>
> I use this e-mail also to make a question, during a work I tried to
>> classify a pancromatic aerial image using an unsupervised approach.
>> Running i.cluster it gave me an error indicating that it needs more
>> than two classes. What I missed?
>>
>
> Dear Michele, the algorithm behind i.cluster does not work with less
> than two input images. See also:
> https://trac.osgeo.org/grass/ticket/1908.
>
> Kind of a common practice, is to use another input derived from the first.
> I.e., some synthetic image, derived from the aerial panchromatic one.
> See https://grass.osgeo.org/grass74/manuals/r.texture.html.
>
> Nikos
>
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