GEO Tagging Photos

GEO tagging photos is merely the ability to present a map with photos placed in the location they were taken. Many photo sites (Flickr and Picasa) support this ability in a fairly robust way. I happen to use Picasa, only because I happen to use several other Google products. Have a peek (but not yet) at my site. To present your photos on a map you have to capture the location (long/lat) where the photo was taken. This can be done in a variety of ways:

1. Buy a GPS receiver for your camera. This is the approach I use with my Nikon D200 and D90 which I described in a earlier blog. The basic idea here is the GPS receiver writes long/lat data into the EXIF information of the photo as you are taking them. Photo sharing sites read this information and plot the photo on a map. BLAM it is that easy.
2. Capture a GPS tracklog and use matching software. This is somewhat of a pain in the arse, but if your camera doesn’t support a GPS your options are limited. See this article for a example of how to marry a GPS tracklog to your photos. The short answer is you set your GPS date/time to be the same as your camera. You run around taking pictures while the GPS is tracking your location. When you get home you use software to match the GPS tracklog date/time to the photo date/time and write the location to the EXIF date of the photo. Upload to a photo sharing site and again BLAM, you’re done.
3. Determine the location of the photo using the capbilities of Flickr or Picasa. This is the for folks who cannot support option 1 or 2. Not terribly efficient but it works. See this Picasa article for more info.

Now, for those of you with a iPhone, note that when you take photos your photos’ EXIF data includes location data. So if you upload your iPhone photos to Picasa your photos will auto-magically display on a map. In case you were wondering, there are iPhone apps which allow you to take a photo, add a caption and send it to your Picasa folder. See PixelPipe for example.

GEO Tracking People

GEO Tracking people is certainly nothing new, but the availability of decent devices at decent prices is what is making it take off. I happen to use my iPhone and an application called Instamapper. Instamapper is an iPhone application which determines your long/lat position and sends it to the Instamapper servers where you can retrieve location data at your convienence through a programmatic API. They provide a URL which shows your current position (assuming you have the app running on your phone) and optionally a track of your last several positions. No biggie right? I agree. But what Instamapper also allows you to do is to programmatically retrieve the location data such that you can build custom sites. And here is where my obession takes off.

GEO Mashups

I wanted a site where I could display my GEO tagged photos from my Nikon DSLR with GPS attachment, my GEO Tagged photos from my iPhone and my current location all on a single Google Map (or Google Earth) with periodic updates. The result is this site which documents my wife and my travels. Once I did that my mind started wandering….

Would it not be cool to track, on a single map, you and your friends? I know Google has their latitudes product but I wanted full control of how the data was displayed. So I came up with this site. Note the link takes you to Google Maps which, due to web caching doesn’t refesh as much as one would like but it works. However, if you click on the “View in Google Earth” link the map will (if you have Google Earth installed on your PC) display a map that will automatically refresh every 90 seconds. So now I am looking for a good use of this technology. I am thinking about a map that displays the current location of hikers or bikers in realtime so long as they have Instamapper running on their phone and have cell service. If, in case of a emergency, they could text someone and say come get me. The rescuer pops open the map and, BLAM, they are saved. How about a fleet of trucks, taxis, your personal vehicle or your kids. If they have a phone with Instamapper installed it is a piece of cake. No, I do not work for Apple or Instamapper, I just happened to have their software installed on my phone. I suspect this could be done with several other apps.

Give me my next challenge….. Enjoy.