[GRASS-dev] Object-based classification [was: Re: i.segment: invalid region id 0]

[Moritz Lennert]

Pietro,

On 31/07/13 10:01, Pietro wrote:
> I'm working to develop a module that use several machine learning
> technique to classify the segments results...
> the part concerning the hierarchical segmentation is working quite well...

Out of curiosity: which variables are you planning on using for this 
classification ?

FYI, here's a list of variables that colleagues established here as 
being the ones they use most in objet-based classification:

- mean band values
- brightness (combination of several band values)
- standard deviation of a certain band within an object
- length/width ratio of an object
- GLCM Homogeneity (Haralick)

All of these are implemented in GRASS, except for the length/width ratio.

And of the Haralick indicator, r.texture is pixel-based, evaluating 
texture in a given neighborhood. Don't know how difficult it would be to 
add the option to calculate the same indicators within the polygons 
defined in a cover map.

Moritz