[Geowanking] Geocoding photos

[Dan Brickley]

Lars Aronsson wrote:
> So, after one year with a GPS receiver, my disk is full with 6500 
> digital photos and 100 GPX files.  In theory I should be able to 
> geocode them all with just some simple script.  But in reality I 
> don't know if my camera's clock was accurate within a few minutes, 
> and I know I forgot to change it to daylight savings time for a 
> few months.  So the timestamps could be out of sync by a few 
> minutes or a whole hour. But in that case, exactly the same time 
> shift is likely to apply to the previous and next 100 images or 
> so.  However, if there are no GPS samples within, say, 20 minutes, 
> the photo should perhaps not be geocoded at all.
> 
> What software should I use for geocoding these photos?  I cannot 
> spend two minutes per picture, since that would take 217 work 
> hours or five full weeks.  I could spend 10 hours, which would 
> average 5 seconds per photo.  I need to be highly productive.
> 
> I guess if I only use the simple script, I'll get within an hour 
> or roughly 100 km.  Perhaps that's an OK start.  Does anybody have 
> a useful program for Linux laying around?
> 
> 

Glad you mentioned it. I found such a thing a couple years ago,
geoloc_media.pl ... not sure even whose it was. I did a bit of
rewriting, see notes at
http://rdfweb.org/people/danbri/media/bin/geoloc_media.pl ...basically
switched the EXIF library so it can write as well as read (and i think
moved to pure perl; was Image::ExifTool instead of Image::EXIF). It uses
some handy CPAN modules too, in particular Rich Gibson's
Geo::Track::Log, see
http://search.cpan.org/~rgibson/Geo-Track-Log-0.02/lib/Geo/Track/Log.pm
("Represent track logs and find a location based on a track log and a
date.").

Googling, I find the original at
http://locative.us/photomap/geoloc_media.pl tho dunno if it's evolved
since my little fork.

Have fun,

Dan

ps. Flickr have launched their mapping thingumy.
http://blog.flickr.com/flickrblog/2006/08/great_shot_wher.html
It noticed a couple of already geo-tagged pics when I ran their
Map-enabled Organizer. I don't know if it spotted the lat/long tags,
...or the embedded Exif which I added via this script. Presumably the
former, thinking in terms of server-load...?