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I am working with vectorized greyscale images converted into polygon layers by the QGIS vetorize tool. Currently I am using a rather long way to get rid of small polygones.

I convert the polygons into lines, run the Generalizer Tool (Plugin) with the Alghorithm "Remove small object" and a Threshold of 2.0 and convert the hole thing back into polygons.

Is there a way to do the same thing without converting the polygons into lines? I tried the v.generalize, but it does not seem to have the same Alghorithm for small object removal.

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Here is the workflow I propose:

  • After vectorization go to attribute table and add a field called area and calculate the area of each feature with $area
  • After this, you can select features with an expression like "area" < 20 for example to get all features which are too small
  • delete those or go the other way by selecting only the desired features and go on the layer -> Save as.. and check the "save only selected features" option
  • after those steps you could still run the "simplify geometries" tool
  • That solved the question. Thanks! Sometimes the solution is so simple, that you just do not see it. – akra-kachi Jun 8 '17 at 15:27

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