... I gather, the "spike removal" you mention averages adjacent pixels (i.e. low-pass filtering). But what you want would be "FourierTransformation" and therefore removing high frequency image components. Unfortunately I do not know whether there is such a feature already implemented.
Kind regards Matt Am 08.10.2011 20:14, schrieb 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... [map prior to filtering] Map after filtering... [map after filtering] Composite map.... [map composite] 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. ________________________________ View this message in context: Smoothing algorithim to remove small spikes<http://osgeo-org.1803224.n2.nabble.com/Smoothing-algorithim-to-remove-small-spikes-tp6873002p6873002.html> Sent from the Grass - Users mailing list archive<http://osgeo-org.1803224.n2.nabble.com/Grass-Users-f1837860.html> at Nabble.com. _______________________________________________ grass-user mailing list [email protected]<mailto:[email protected]> http://lists.osgeo.org/mailman/listinfo/grass-user -- Mit freundlichen Grüssen Matthias Rumitz Senior Systemberater Server- & Storage dignum GmbH Direktkontakt: VoIP direct: +49 (0)8152-9299 114 Mobil: -49 (0)172-83876 14 eMail: [email protected]<mailto:[email protected]> Postanschrift Standort: Am Technologiepark 14 - 16 D-82229 Seefeld Zentrale: +49 (0)8152-9829 0 Fax: +49 (0)8152-9829 22 www.dignum.de<http://www.dignum.de> Niederlassungen: Seefeld - Karlsbad - Kelkheim - Essen _____________________________________ Name der Gesellschaft: dignum GmbH Sitz: Seefeld, Bayern Amtsgericht: München, HRB 147 408 Geschäftsführer: Armin Sammet, Volker Enkelmann ---------------------------------------------- dignum GmbH Am Technologiepark 14-16, 82229 Seefeld Tel.: +49-8152-92991-0, Fax: +49-8152-92991-22 www.dignum.de<http://www.dignum.de/> ---------------------------------------------- Standorte der Firmengruppe: München, Essen, Frankfurt, Karlsruhe, Hannover, Berlin, Krakau/Polen. Name der Gesellschaft: dignum GmbH, Sitz der Gesellschaft: Seefeld, Amtsgericht: München, Handelsregister: HRB 147 408, Geschäftsführer: Armin Sammet, Volker Enkelmann Diese E-Mail ist vertraulich zu behandeln. Sie kann besonderem rechtlichen Schutz unterliegen. Wenn Sie nicht der richtige Adressat sind, senden Sie bitte diese E-Mail an den Absender zurück, löschen die eingegangene E-Mail und geben den Inhalt der E-Mail nicht weiter. Jegliche unbefugte Bearbeitung, Nutzung, Vervielfältigung oder Verbreitung ist verboten. / This e-mail is confidential and may also be legally privileged. If you are not the intended recipient please reply to sender, delete the e-mail and do not disclose its contents to any person. Any unauthorized review, use, disclosure, copying or distribution is strictly prohibited.
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