[GRASS-user] Performing a Maximum Likelihood Supervised classification with a single band

[umberto.minora]

Ciao Veronica,

thanks for the hint and sorry for the late feedback.
I'd like to use GRASS so I might go for the "r.texture" solution. 
Anyway, I did not get how to use it for my scope.
First of all, as I already have training areas, i want to use them in a 
Supervised classification rather than an unsupervised one (as ISODATA).
Second, I am only interested in using one band for the classification, 
which was the reason I could not use "i.maxlik".
Now, as I understand, using "r.texture" will generate images with 
textural features from my single band raster map. I got that I could use 
these as the needed input for the "i.maxlik", but I did not get what 
"r.texture" will give me, and if that is going to be a good statistic 
sample for the Supervised. Moreover, which method would you suggest?
I am pretty new to this function, so I hope you (or anyone else) could 
give me a hand to better understand it.
Thanks in advance!

Il 08/10/2015 22:21, Veronica Andreo ha scritto:
> Ciao Nikos :)
>
> Yes, you are right! I missed that one!
>
> There's ISODATA unsupervised classification algorithm (not in GRASS 
> that I know) and it allows for just one band input.
>
> Cheers,
> Vero
>
> 2015-10-08 16:52 GMT-03:00 Nikos Alexandris <nik a nikosalexandris.net 
> <mailto:nik a nikosalexandris.net>>:
>
>     * Veronica Andreo:
>
>     > Ciao Umberto,
>     >
>     > AFAIK, classification is multivariate on its statistical basis,
>     so that's
>     > why it will only take a group as input. If you only have one
>     band, you may
>     > want to extract some information from it, for example by using
>     r.texture
>     > module [1]. With those resulting new bands and the original one
>     you can
>     > create then a group and perform the classification you prefer.
>     > [1] https://grass.osgeo.org/grass71/manuals/r.texture.html
>
>
>     Ciao Vero.  There is, for example, the ISODATA algorithm out there.
>     Just not in GRASS (yet?).
>
>     Nikos
>
>

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