An imposm parser for
OSM QA tiles. osmqa-parser was
written for use with tile-reduce-py
and osmgraph.
The parser should be used with an imposm importer such as the one found in
osmgraph.
OSM QA tiles are delivered as Mapbox Vector Tiles. It is impossible to exactly reconstruct the original OSM data from a vector tile.
Because ways in a QA tile contain a coordinate sequence instead of a node
sequence, we can't distinguish different nodes that have the same tile
coordinate. osmqa-parser assigns unique node IDs based on tile coordinate.
As a result, it's possible we introduce false intersections which arise when
two ways have different nodes that have the same coordinates. Also, different
nodes that fall on the same tile coordinate will have identical node IDs,
which usually means their tags are merged together as one.