<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body bgcolor="#ffffff">
... I gather, the "spike removal" you mention averages adjacent pixels (i.e. low-pass filtering).<br>
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.<br>
<br>
Kind regards<br>
Matt<br>
<br>
<br>
Am 08.10.2011 20:14, schrieb spiderplant0:
<blockquote type="cite">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...
<img src="http://osgeo-org.1803224.n2.nabble.com/file/n6873002/grass_test2_input.jpg" alt="map prior to filtering" border="0"> Map after filtering...
<img src="http://osgeo-org.1803224.n2.nabble.com/file/n6873002/grass_test2_filtered.jpg" alt="map after filtering" border="0"> Composite map....
<img src="http://osgeo-org.1803224.n2.nabble.com/file/n6873002/grass_test2_both.jpg" alt="map composite" border="0"> 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. <br>
<hr width="300" align="left">
View this message in context: <a href="http://osgeo-org.1803224.n2.nabble.com/Smoothing-algorithim-to-remove-small-spikes-tp6873002p6873002.html">
Smoothing algorithim to remove small spikes</a><br>
Sent from the <a href="http://osgeo-org.1803224.n2.nabble.com/Grass-Users-f1837860.html">
Grass - Users mailing list archive</a> at Nabble.com.<br>
<pre>
<fieldset class="mimeAttachmentHeader"></fieldset>
_______________________________________________
grass-user mailing list
<a class="moz-txt-link-abbreviated" href="mailto:grass-user@lists.osgeo.org">grass-user@lists.osgeo.org</a>
<a class="moz-txt-link-freetext" href="http://lists.osgeo.org/mailman/listinfo/grass-user">http://lists.osgeo.org/mailman/listinfo/grass-user</a>
</pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
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: <a class="moz-txt-link-abbreviated" href="mailto:Matthias.Rumitz@dignum.de">Matthias.Rumitz@dignum.de</a>
Postanschrift Standort:
Am Technologiepark 14 - 16
D-82229 Seefeld
Zentrale: +49 (0)8152-9829 0
Fax: +49 (0)8152-9829 22
<a class="moz-txt-link-abbreviated" href="http://www.dignum.de">www.dignum.de</a>
Niederlassungen:
Seefeld - Karlsbad - Kelkheim - Essen
_____________________________________
Name der Gesellschaft: dignum GmbH
Sitz: Seefeld, Bayern
Amtsgericht: München, HRB 147 408
Geschäftsführer: Armin Sammet, Volker Enkelmann</pre>
<p>----------------------------------------------<br>
<font face="Arial, sans-serif"><font size="1" style="font-size:8pt">dignum GmbH<br>
Am Technologiepark 14-16, 82229 Seefeld<br>
Tel.: +49-8152-92991-0, Fax: +49-8152-92991-22<br>
<a href="http://www.dignum.de/">www.dignum.de</a><br>
----------------------------------------------<br>
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</font></font><br>
<font face="Arial, sans-serif"><font size="1" style="font-size:7pt">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.
</font></font><font face="Arial, sans-serif"><font size="1" style="font-size:7pt"><span lang="en-US">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.</span></font></font></p>
<p style="margin-bottom:0cm"><br>
</p>
</body>
</html>