[GRASS-user] Question to the input seed grid of i.segment

[Moritz Lennert]

Le Fri, 10 Feb 2017 19:15:25 +0100,
Paulo van Breugel <p.vanbreugel at gmail.com> a écrit :

> On 10-02-17 18:41, Moritz Lennert wrote:
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> >> Besides, manually, I calculated
> >> Moran's I and Intrasegment Variance by i.segment with 8 instead of
> >> 4 neighbors (default). Even if the object looks kind of "
> >> pixelated" at the border, I received smaller Moran's I and
> >> Intrasegment Variance values with i.segment 8 NB in comparison to
> >> 4 NB (same settings for minsize and threshold). Maybe the "-d"
> >> flag of i.segment could also be added to i.segment.uspo...  
> >
> > That shouldn't be too difficult. Internally, i.segment.uspo uses
> > the addon r.neighborhoodmatrix which has a '-d' flag. I just really
> > do not have the time to implement this right now. You could try
> > yourself by opening the i.segment.uspo (or on Windows
> > i.segment.uspo.py) file and adding "flags='d'" to the call to
> > r.neighborhoodmatrix (lines 535 and following):
> >
> >     res = gscript.read_command('r.neighborhoodmatrix',
> >                                input_=mapname,
> >                                output='-',
> >                                sep='comma',
> >                    flags='d',
> >                                quiet=True)
> >
> >
> > This will always apply the flag. When I have time I can add this as
> > a flag to i.segment.uspo.
> >
> > A slightly larger project I have is to actually extract the code
> > for the calculation of the spatial autocorrelation and create a 
> > "r.spatialautocorrelation" module. But not now... ;-)  
> 
> +1 (or make that a double plus) that would be really great!


r70696: r.object.spatialautocor: new addon to calculate global spatial
autocorrelation for raster objects

Moritz