[Digikam-users] GPS - other maps than worldmap.jpg?

Arnd Baecker arnd.baecker at web.de
Wed Sep 6 13:16:32 BST 2006


Hi,

the new GPS view in digikam svn is very nice.

Is there a way to add user-supplied maps?

This would require to have a .jpg (etc.) image of a map
together with corresponding geographical information.

One approch would be to provide the geographical information
is  to use the "world file format",
see e.g.
http://www.gpsphone-forums.com/showthread.php?p=38
http://www.nps.gov/gis/av3_online/documents/section7/docs/section7_pg3.html

To create maps with geographical information
the section "Georeferencing"
http://www.gdf-hannover.de/lit_html/grass60_v1.2_en/node31.html
in the GRASS documentation seems helpful.

Another option to create those maps is `Karto`
which allows to calibrate a scanned map with some
known geo-points (Lambert, UTM, etc.).
http://freshmeat.net/projects/karto/

Has anyone already tried something in this direction?

Best, Arnd

P.S.: Of course there are a couple problems to be solved, like
- selection of the presently shown map:
  I.e., from what zoom level on does one switch
  to a more detailed map (if available)?
- switching from one map to another if there is partial overlap
  (or how to blend them together?)
- open source/free georeferenced maps seem to be rare.

But maybe for a start one could just allow the user
to select from a list of maps and just display that one.


P.P.S.: This GPS stuff opens cans of worms: for example
associating a GPS track with a folder or set of images
and display of the track in the corresponding map would be cool.




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