Install osmcoastline with Homebrew, apt

Project links

• Homepage
• Repository
• Upstream docs
• Package manager page

Commands and aliases

• osmcoastline
• osmcoastline_filter
• osmcoastline_readmeta
• osmcoastline_segments
• osmcoastline_ways

Project history

Jochen Topf announced the work on March 7, 2012, while explaining the long-standing problem of turning `natural=coastline` ways into proper polygons. The same day, the osmcode/osmcoastline GitHub repository was created.

The blog post frames osmcoastline as a rewrite of an older coastcheck-based workflow that had become slow and difficult to maintain. The new implementation used Osmium to scan OSM files, assemble coastline rings, produce error information, and leave room for output options such as land polygons, water polygons, clipping, and splitting.

Adoption history

OpenStreetMapData's coastline-processing page says OSMCoastline was developed specifically to assemble coastline data, apply fixes where needed, and create the published coastline datasets on that site. It also feeds detected coastline errors onward to Geofabrik's OSM Inspector so mappers can correct source data.

How it is used

The man page describes `osmcoastline` as reading an input file, usually a planet file or filtered output, and writing coastline polygons to a Spatialite database. Options control overlap, gap-closing distance, warning behavior, output formats, and projection-specific details.

The repository also ships helper commands such as `osmcoastline_filter`; the README says the filter can reduce a planet file to the nodes and ways needed for coastline assembly, producing a file less than one percent of the original planet size.

Why package nerds care

osmcoastline is a compact example of domain-specific packaging: it depends on OSM parsing, geometry libraries, Spatialite, GDAL, GEOS, zlib, and optional PBF compression details, but exposes a focused CLI for one global map-production job.

Timeline

• 2012-03-07: Jochen Topf publishes the OSM Coastlines blog post and releases the osmcoastline code.
• The project grows around libosmium, protozero, GDAL, GEOS, SQLite/Spatialite, and PBF support.
• OpenStreetMapData uses OSMCoastline for published coastline processing and error reporting.

Related projects

• libosmium provides OSM file handling; OpenStreetMapData publishes derived coastline datasets; Geofabrik OSM Inspector surfaces coastline errors; renderers consume the assembled land and water polygons.

Sources

• https://api.github.com/repos/osmcode/osmcoastline
• https://blog.jochentopf.com/2012-03-07-osm-coastlines.html
• https://docs.osmcode.org/osmcoastline/master/osmcoastline.html
• https://formulae.brew.sh/formula/osmcoastline
• https://github.com/osmcode/osmcoastline
• https://osmcode.org/osmcoastline/
• https://osmdata.openstreetmap.de/processing/coastline.html