I have a b&w image i want to classify; the trouble is that mere spectral classification yields a lot of error, I saw this in wikigrass
In case of panchromatic maps or limited amount of channels, it is often recommended to generate synthetic channels through texture analysis (r.texture)
And there's nothing more about it in that page; How can I use the outcome from r.texture in a classification, together with the segments of i.segment or i.smap?