[GRASS-user] supervised image classification using textural aspects

[Markus Neteler]

Wout,

On Fri, Aug 22, 2008 at 2:29 PM, Wout Bijkerk <wout.bijkerk at xs4all.nl> wrote:
...
> Looking at the images, I wonder if including textural features within
> the images would be usefull: a forest canopy has a far coarser texture
> than a grassland. Also in the Grassbook this is mentioned, and for the
> supervised classification of saltmarshes in Germany, textural features
> are also used
...
> 1) Is it usefull to make a raster with textural image features  as an
> extra input for i.gensigset / i.smap? The i.gensigset / i.smap procedure
> is partly based on geometry and therefor on texture as well so what does
> a texturemap add?
...

It's worth trying. I have done so for orthophoto classification and
it definitely helped:
http://mpa.itc.it/markus/ortho_smap/

The texture map(s) add patterns which can stabilize the process
of assigning pixels to classes/can improve the segmentation part
of i.smap as it renders heterogeneous areas to homogeneous
areas.

Markus