[KPhotoAlbum] Geotagging and searches within KPhotoAlbum

[Walter Francis]

I asked Jan about Geotagging in KPA today on IRC and he suggested I start a
bit of a discussion on the matter on this list to describe some use cases and
get additional input, so anyone feel free to jump in here!

Some very limited number of cameras have built-in GPS units, some other
cameras have optional GPS units which can be attached.  In either scenario,
the images taken with the cameras are tagged with EXIF data indicating their
latitude, longitude, typically altitude, datum, etc..  I haven't yet heard
anything suggesting GPS will become a common built-in feature in cameras.

Similar, but using separate processes, there are also methods to combine
information from a GPS with information from a digital photo and geotag the
images later.  Correlating the DateCreated (or perhaps other timestamps) from
the photo and looking for the closest datapoint from a GPS data file, one can
then write the GPS tags into the EXIF data.  There are several ways to do
this, some of them online, some of them scripted, some minimal GUI, etc.

See here for more info on geotagging:  http://en.wikipedia.org/wiki/Geotagging

I have some following example use cases and suggested implementation ideas for
both tagging and then referencing the data after.

Use case 1:
User does not have a GPS, but wishes to geotag their images for future
reference within KPhotoAlbum

Possible implementations/options:
KPA displays a map from online data (ex: Google Maps) and allows click-to-pick
spot.  Must be able to zoom in, display sat/hybrid.

KPA displays Geolocation input in the Single and Multiple Edit Photo screens
(lat, lon, perhaps even geolocation using online lookups to get lat,lon)

KPA accepts a GPS datafile (kml, gpx, nmea(?)) and then looks for images
within its database which match the GPS data and update the image EXIF and
database with the data.  Will need time offset and time window (how long away
is a valid time point) options.  Writing the EXIF data could be an option, but
is necessary to make available for referencing external to KPA.

Use case 2:
User wishes to find all images within a certain area.

Possible implementations/options:
KPA displays Geolocation input in the Search screen (lat, lon, perhaps even
geolocation using online lookups to get lat,lon)

KPA allows you to search images near the current image you're viewing

KPA displays a map and plots image points on the map.  This could be internal
to KPA, or KPA could generate the data and launch it in a browser for viewing.

Use case 3:
User wishes to see the location of an image as he views it (single view,
slideshow, etc).

Possible implementations/options:
KPA shows a small, simple map when viewing a single image, similar to the EXIF
View popup.

KPA displays Geolocation data in EXIF View popup (Image taken near City,
State/Country)

-- 
Walter Francis

khayts.us
theblackmoor.net
unlimitedphoto.com