[GRASS-user] Smoothing algorithim to remove small spikes

[spiderplant0]

Hi, I have a vector map that has some narrow features (boat jettys etc) that
I wish to smooth out. Can anyone suggest a method of achieving this please?
I have tried several of the algorithims in v.generalise without success. 

One of the problems I am experiencing is that small details seem to be
treated similarly to large scale detail. 

See links to example using snakes method.


Map prior to filtering...
http://osgeo-org.1803224.n2.nabble.com/file/n6873002/grass_test2_input.jpg 


Map after filtering...
http://osgeo-org.1803224.n2.nabble.com/file/n6873002/grass_test2_filtered.jpg 


Composite map....
http://osgeo-org.1803224.n2.nabble.com/file/n6873002/grass_test2_both.jpg 


At the bottom-left of the map I have small spikes that I want smoothed over.
They have been smoothed out reasonably well but the large spike has been
converted into a short fat spike. I.e. it has been reduced in size by around
the same percentage as the small ones. Also at the top-right of the map, a
huge area of land has been chopped off. 

Its as if the smoothing algorithm didnt take account of scale but just
consider a number of vertices each side of the point and apply the filter
without considering how far apart in metres the points are.

What I'm looking for is a way to smooth out the small detail especially
small spikes, but not chop out big areas of land at larger scales.


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