Filters in Osmosis; filtering administrative boundaries

Question

I am trying to filter administrative boundaries of admin_level 4. I carefully read the Osmosis reference and some examples, and composed the following query (the chevrons allow to feed multiple lines into the Windows Command Prompt):

osmosis ^
  --read-pbf-fast workers=2 "D:/GIS Data/Data/netherlands-latest.osm.pbf" ^
  --tf accept-relations boundary=administrative ^
  --tf accept-relations admin_level=4 ^
  --tf reject-ways ^
  --tf reject-nodes ^
  --used-way ^
  --used-node ^
  --write-pbf omitmetadata=true file="D:/GIS Data/Tijdelijk/provinciestestosmosis.osm.pbf"

This works fine in the sense that it yields all the required relations (checked the OSM file manually). However, no ways of nodes are included, which is not what I wanted as I need them to plot the administrative boundaries. It seemed an obvious error to me as I first accept the required relations, then reject all ways and nodes, leaving Osmosis unable to resolve the used ways and nodes in the relations.

Then did the following, however this yields the same result:

osmosis ^
  --read-pbf-fast workers=2 "D:/GIS Data/Data/netherlands-latest.osm.pbf" ^
  --tf accept-relations boundary=administrative ^
  --tf accept-relations admin_level=4 ^
  --used-node ^
  --tf reject-ways ^
  --tf reject-nodes ^
  --write-pbf omitmetadata=true file="D:/GIS Data/Tijdelijk/provinciestestosmosis.osm.pbf"

Then did the following:

osmosis ^
  --read-pbf-fast workers=2 "D:/GIS Data/Data/netherlands-latest.osm.pbf" ^
  --tf accept-relations boundary=administrative ^
  --tf accept-relations admin_level=4 ^
  --tf accept-ways ^
  --tf accept-nodes ^
  --used-ways ^
  --used-node ^
  --write-pbf omitmetadata=true file="D:/GIS Data/Tijdelijk/provinciestestosmosis.osm.pbf"

However this yields an enormous result (700 MB PBF file), including far more data then is neccessary for the selected relations. Can someone please elaborate on how to exactly read the Osmosis queries and show an example of what is the correct query (relations:admin_level=4 including depending sub-relations, ways and nods)?

BTW: This question is related to my question about Osmfilter.

Answer 1

The following works correct. First filter the relations (step 1), then filter the ways (step 2) en then filter the nodes (step 3). I must say, Osmosis is not a very straight forward tool to use.

Step 1:

osmosis ^
  --read-pbf-fast workers=2 "D:/GIS Data/Tijdelijk/netherlands-latest.osm.pbf" ^
  --tf accept-relations boundary=administrative ^
  --tf accept-relations admin_level=4 ^
  --write-pbf file="D:/GIS Data/Tijdelijk/step1.osm.pbf"

Step 2:

osmosis ^
  --read-pbf-fast workers=2 "D:/GIS Data/Tijdelijk/step1.osm.pbf" ^
  --used-way ^
  --write-pbf file="D:/GIS Data/Tijdelijk/step2.osm.pbf"

Step 3:

osmosis ^
  --read-pbf-fast workers=2 "D:/GIS Data/Tijdelijk/step2.osm.pbf" ^
  --used-node ^
  --write-pbf file="D:/GIS Data/Tijdelijk/step3.osm.pbf"

Are there any suggestions on how to improve the rather tedious method? :)

Filters in Osmosis; filtering administrative boundaries

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