Digikam/GSoC2010/ReverseGeocoding
Reverse geocoding will be implemented for the new version of the GPSSync plugin as part of GSOC by Gabriel Voicu, mentored by Michael G. Hansen.
Short description
The idea of reverse geocoding is that when the coordinates on earth of an image are known, the application retrieves the associated human readable location: City, street, country, etc. and stores this information in the image. The location names can be stored in the images as new tags, allowing the user to easily search for all pictures he took in a country, city or even street.
Where is the code?
- gsoc-geocoding: General place for experiments and small code snippets.
- GPSSync2: New version of the GPSSync plugin.
- WorldMapWidget2: Widget to display the location of images on both Google Maps and Marble. Required by GPSSync2.
Backends
Google Maps
- provides both reverse geocoding and elevation information
- returns for each coordinate:
- country and administration zone if the coordinate is not inside a city
- country, administration zone and city if the coordinate is inside a city but not inside a street
- country, administration zone and street if the coordinate is inside a street but not inside a city
- country, administration zone, city and street(eventually and street number) if the coordinate is inside a city street
OpenStreetMap Nominatim
- Marble already has integration for this service
Geonames.org
- provides both reverse geocoding and elevation information
Storing information
The textual location descriptions can be stored as tags and in the dedicated location fields provided by XMP and IPTC. However, there are some competing tags which store the same information.