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.


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

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.