NAME

       osmcoastline - extract coastline from OpenStreetMap data

SYNOPSIS

       osmcoastline [OPTIONS] –output-database=OUTPUT-DB INPUT-FILE

DESCRIPTION

       osmcoastline extracts the coastline data from the INPUT-FILE, usually a planet file (or the output of the
       osmcoastline_filter  program,  see  below)  and  assembles  all  the  pieces into polygons for use in map
       renderers etc.

       The output is written to the Spatialite database OUTPUT-DB.  Depending on the options it will contain the
       coastlines in different formats.  See the description of the options below and the README.md for details.

OPTIONS

       -h, –help
              Display usage information.

       -b, –bbox-overlap=OVERLAP
              Polygons that are too large are split into  two  halves  (recursively  if  need  be).   Where  the
              polygons  touch  the  OVERLAP is added, because two polygons just touching often lead to rendering
              problems.  The value is given in the units used for the projection (for WGS84 (EPSG: 4326) this is
              in degrees, for Mercator (EPSG: 3857) this is in meters).  If this is set too small you might  get
              rendering  artefacts where polygons touch.  The larger you set this the larger the output polygons
              will be.  The best values depend on the map scale or zoom level you are preparing  the  data  for.
              Disable the overlap by setting it to 0.  Default is 0.0001 for WGS84 and 10 for Mercator.

       -c, –close-distance=DISTANCE
              osmcoastline  assembles ways tagged natural=coastline into rings.  Sometimes there is a gap in the
              coastline in the OSM data.  osmcoastline will close this gap if it is smaller than DISTANCE.   Use
              0 to disable this feature.

       -d, –debug
              Enable debugging output.

       -f, –overwrite
              Overwrite output file if it already exists.

       -i, –no-index
              Do  not  create spatial indexes in output db.  The default is to create those indexes.  This makes
              the database larger, but data access is faster.

       -l, –output-lines
              Output coastlines as lines to database file.

       -m, –max-points=NUM
              Set this to 0 to prevent splitting of large  polygons  and  linestrings.   If  set  to  any  other
              positive  integer  osmcoastline  will try to split polygons/linestrings to not have more than this
              many points.  Depending on the overlap defined with -b  and  the  shape  of  the  polygons  it  is
              sometimes  not possible to get the polygons small enough.  osmcoastline will warn you on STDERR if
              this is the case.  Default is 1000.

       -o, –output-database=FILE
              Spatialite database file for output.  This option must be set.

       -p, –output-polygons=land|water|both|none
              Which polygons to write out (default: land).

       -r, –output-rings
              Output rings to database file.  This is used for debugging.

       -s, –srs=EPSGCODE
              Set spatial reference system/projection.  Use 4326 for WGS84 or 3857 for “Web Mercator”.   If  you
              want  to  use  the  data  for  the  usual tiled web maps, 3857 is probably right.  For other uses,
              especially if you want to re-project to some other projection,  4326  is  probably  right.   Other
              projections are currently not supported.  Default is 4326.

       -S, –write-segments=FILENAME
              Write  out  all  coastline  segments  to the specified file.  Segments are connections between two
              points.   The  segments  are  written  in  an  internal  format  intended   for   use   with   the
              osmcoastline_segments  program  only.  The file includes all segments actually in the OSM data and
              only those.  Gaps are (possibly) closed in a  later  stage  of  running  osmcoastline,  but  those
              closing segments will not be included.

       -v, –verbose
              Gives you detailed information on what osmcoastline is doing, including timing.

       -V, –version
              Display program version and license information.

NOTES

       To speed up processing you might want to run the osmcoastline_filter program first.  See its man page for
       details.

DIAGNOSTICS

       osmcoastline exits with exit code

       0      if everything was okay

       1      if there were warnings while processing the coastline

       2      if there were errors while processing the coastline

       3      if there was a fatal error when running the program

       4      if there was a problem with the command line arguments.

EXAMPLES

       Run osmcoastline on a planet file using default options:

              osmcoastline -o coastline.db planet.osm.pbf

       Running osmcoastline_filter first:

              osmcoastline_filter -o coastline.osm.pbf planet.osm.pbf
              osmcoastline -o coastline.db coastline.osm.pbf

SEE ALSO

       • README.md

       • osmcoastline_filter(1), osmcoastline_readmeta(1), osmcoastline_segments(1), osmcoastline_ways(1)

       • Project page (https://osmcode.org/osmcoastline/)

       • OSMCoastline in OSM wiki (https://wiki.openstreetmap.org/wiki/OSMCoastline)

COPYRIGHT

       Copyright  (C)  2012-2019  Jochen  Topf  <jochen@topf.org>.   License  GPLv3+: GNU GPL version 3 or later
       <https://gnu.org/licenses/gpl.html>.  This is free software: you are free to change and redistribute  it.
       There is NO WARRANTY, to the extent permitted by law.

CONTACT

       If you have any questions or want to report a bug, please go to https://osmcode.org/contact.html

AUTHORS

       Jochen Topf <jochen@topf.org>.

                                                      2.2.4                                      OSMCOASTLINE(1)