I have done the land use classification for sentinel imagery. Now I want to create boundaries, within that classified image, enclosing different classified section. For example boundaries for water, forest etc. If a category has more than one portion inside the image, then it can have more than one enclosing boundaries. Like, the forest can have more than one enclosing boundaries depending on where foreset has been detected inside the image.

How can I perform this operation? (in QGIS)

For example - I have shapefile of the complete image given below. I want to create shapefiles for each unique colour in the image.

enter image description here

  • Do you mean like this docs.qgis.org/2.8/en/docs/training_manual/complete_analysis/… ? It might help if you gave us a screen shot of what you have and hand draw what you expect to get out of it, as it stands your question is a little bit vague on your data in hand and your expectation. Nov 5, 2019 at 6:28
  • @MichaelStimson Thanks for the prompt reply. I have edited the question and included a sample image too. I hope now it will be more clear. Nov 5, 2019 at 6:37
  • Do you have a legend as to what the colours mean? I see a red shape that appears to mix with the adjacent areas, are you expecting to get the red stained area as a separate polygon or is each unique colour its own polygon? Read gis.stackexchange.com/questions/113539/… and see if anything there sheds some light on your problem. In Esri I would build a raster attribute table then export raster to polygon then split classes by attributes into new shapefiles though I think in QGIS you do that in reverse order. Nov 5, 2019 at 6:43


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