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)