On Wed, Jan 18, 2017 at 8:16 PM, Giuseppe Amatulli < giuseppe.amatu...@gmail.com> wrote: > > Hi all, > > I would like to "segment" an image using a sort of Voronoi algorithm on a cost surface instead of distance between point. > > Below you can see an image where the black pixels identity areas with high cost value. I would like to identify the "valley" between theses black areas. > > In the second image I draft by hand an ideal solution for few high cost areas. > > Which grass command can do this kind of delineation?
You can use v.voronoi: first extract the pixels with high cost values with e.g. r.mapcalc "high_cost = if(surface_map > threshold_value, 1, null())" Then convert to vector areas with r.to.vect input=high_cost output=high_cost type=area Now create Voronoi triangles for areas with v.voronoi input=high_cost output=high_cost_voronoi -a HTH, Markus M > > Thanks, > > Giuseppe > > > > > > > -- > Giuseppe Amatulli, Ph.D. > > Research scientist at > Yale School of Forestry & Environmental Studies > Yale Center for Research Computing > Center for Science and Social Science Information > New Haven, 06511 > Teaching: http://spatial-ecology.org > Work: https://environment.yale.edu/profile/giuseppe-amatulli/ > > > > > _______________________________________________ > grass-user mailing list > grass-user@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/grass-user
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