[GRASS-user] Road and river extraction using GRASS

[Anna Kratochvílová]

Hi,

On Wed, Oct 17, 2012 at 7:50 PM, António Rocha
<antonio.rocha at deimos.com.pt> wrote:
> Greetings,
> Is there any GRASS module that can be used to river and road extraction from
> satellite images? Some feature extraction algorithm

you can try new (and experimental) modules from grass7 addons - i.edge
and r.houghtransform. i.edge is for detecting edges using canny edge
detection algorithm [1] and r.houghtransform uses hough transformation
[2] to detect straight lines (maybe good for roads but not usable for
rivers).
r.houghtransform can take the output of i.edge as an input.
Unfortunately there is no information in the man page yet but you can
always ask.

Anna

[1] http://en.wikipedia.org/wiki/Canny_edge_detector
[2] http://en.wikipedia.org/wiki/Hough_transform


> Thank you
> Regards,
> Antonio Rocha
> _______________________________________________
> grass-user mailing list
> grass-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-user