NAME

downloadosmtiles.pl - Download map tiles from OpenStreetMap

SYNOPSIS

  downloadosmtiles.pl --lat=49.5611:49.6282 --lon=10.951:11.0574 --zoom=13:14
  downloadosmtiles.pl --link='http://www.openstreetmap.org/?lat=-23.5872&lon=-46.6508&zoom=12&layers=B000FTF'

DESCRIPTION

This script downloads all map tiles from an OpenStreetMap tile server for some geographic region in a range of zoom levels. The PNG images of the tiles are stored in a directory tree that mirrors the paths from the server.

A bounding box of geographic coordinates and a range of zoom levels must be selected by command line options.

COMMAND LINE OPTIONS

Command line options may be abbreviated as long as they remain unambiguous.

At least either --latitude, --longitude, and --zoom or --link must be specified.

--latitude=latmin[:latmax]

Selects the latitude of the bounding box of coordinates to download. May be one single real value or two real values separated by a colon in the range -85.0511..85.0511. If given only one value, just the tile (or row of tiles) at this latitude will be downloaded.

Default: none

--longitude=lonmin[:lonmax]

Selects the longitude of the bounding box of coordinates to download. May be one single real value or two real values separated by a colon in the range -180.0..180.0. If given only one value, just the tile (or column of tiles) at this longitude will be downloaded.

Default: none

--zoom=zoommin[:zoommax]

Selects the range of zoom levels to download the map tiles for. May be one single integer value or two integer values separated by a colon. OpenStreetMap supports zoom levels in the range 0..18. (This depends on the base URL and is not enforced by this script.)

Note that the number of tiles to download grows by a factor of up to four with each zoom level.

Default: none

--link=url

An URL selecting --latitude, --longitude, and --zoom in one argument. The idea is to select the current view of OSM's slippy map by its permalink.

The argument to --link must be an URL containing the HTTP options ?lat=s&lon=s&zoom=s. (Actually, the base URL will be ignored.) The script chooses a box around the latitude and longitude options. The size of the box depends on the zoom option.

If combined with --latitude, --longitude, or --zoom, these explicitly specified values override the implicitly specified values from --link.

Default: none

--baseurl=url

The base URL of the server to download the tiles from.

Default: http://tile.openstreetmap.org (This is the base URL for the Mapnik tiles.)

--destdir=dir

The directory where the tiles will be stored. The PNG files will be stored as dir/zoom/x/y.png.

Default: The current working directory.

--quiet

Do not write any diagnostic messages. Only fatal errors will be reported.

EXAMPLE

Select the region of interest in OSM's slippy map and follow the permalink in the lower left of the window. Lets assume this permalink to be http://www.openstreetmap.org/?lat=49.5782&lon=11.0076&zoom=12&layers=B000FTF. Then

  downloadosmtiles.pl --link='http://www.openstreetmap.org/?lat=49.5782&lon=11.0076&zoom=12&layers=B000FTF' --zoom=5:18

will download all tiles from zoom level 5 to 18 for this region.

ENVIRONMENT

http_proxy
ftp_proxy
xxx_proxy
no_proxy

These environment variables can be set to enable communication through a proxy server. This is implemented by LWP::UserAgent.

BUGS

  • Ranges in the command line options must always be increasing. While this is considered a feature for --latitude and --zoom, it means that it is impossible for a range in the --longitude argument to cross the 180 degree line. A command line option like --longitude=179.5:-179.5 will not work as one should expect.

  • The bounding box selected by the --link command line option does not always correspond to the current view in the slippy map. The problem is that the permalink from the slippy map only contains one position and not the bounds of the current view. The actual view of the slippy map depends on many factors, including the size of the browser window. Thus, there is not much that can be done about this issue.

SEE ALSO

http://wiki.openstreetmap.org/wiki/Slippy_Map

AUTHOR

Rolf Krahl <rolf@rotkraut.de>

COPYRIGHT AND LICENSE

Copyright (C) 2008 by Rolf Krahl

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.