Re: OBIA image segmentation with GRASS, i.segment(.uspo)
Please note that in general it is considered bad netiquette to address
such a mail to individual developers instead of the project mailing list
 (in CC). I, therefore, invite you to use that channel for communication.
This should be solved with the imminent 7.4.4 release.
> * installed GRASS 7.4.0 on Ubuntu using Oracle Virtualbox, where
> i.segment works * did some try&error with i.segment with different
> thresholds and different minsize parameters for an rgb image (made
> from the example tiff  using r.composite)
i.segment will certainly work better if you provide it as input a group
of three different r, g, b maps, instead of one single r.composite
output, because then it will have three variables on which to determine
similarity between pixels instead of only one.
> * installed add-on’s i.segment.stats and i.segment.uspo,
> r.neighborhoodmatrix * gave i.segment.uspo a trial run, but the
> result wasn’t really what I was looking for. I assume more tuning is
Without more explanation of what you are looking for and in what ways
the results diverged from that expectation, it is difficult to help you
> Do you think that this is an efficient approach to solve the
> question, how many square meters are damaged by wild boar in a
> specific field?
I don't really know how such damage manifests itself spectrally and how
important "objects" are for detection, compared to pixel-by-pixel
information. It might be that for this particular question a pixel-based
approach might be more relevant. If you want to try machine learning
algorithms on this, you can look at the r.learn.ml addon.