Geotagging photos...without breaking the bank

Cameras with built in GPS receivers are becoming more and more popular, and common. This is a great feature an allows you to review exactly where you took that holiday photo (which beach in the Australia was that anyway?!). Many photo management tools, both online and local, such as Flikr and iPhoto will happily show you a map of your photo exploits and allow others the share your travels too. Unfortunately many (most) cameras don't have native GPS receivers, but there's a cheap and easy way to achieve the same end result with some simple software and a mobile phone. I make an apology at this point; the rest of this post focusses on two tools for the Apple eco-system. There are equivalents for Windows and Android too - the workflow is the same, just the tools are different.

The idea is simple enough; whilst not all cameras have a GPS, practically ANY smart phone does. So if we use the phone the track our location then add that location data to our photos, we've achieved exactly the smae result as our smug GPS-enabled-camera friends. In some ways, this method is even better as you only need a single GPS for a whole range of cameras provided your group (such as a family holiday) are more or less in the same place. The only caveat is that the GPS and all cmaeras need to have their clocks in sync. Not perfectly in sync, but at least within a minute or two. This is actually a lot easier than it sounds.

Step One - Get the software

I use two tools:

  1. Geotag Photos Pro - this runs on iOS and turns your iPhone into a full-featured geotagging tool. Configurable to record your location based on time or how far you've move from your previously detected position. Stores the results in Dropbox too for easy retrieval later. I ran this for nearly 2 weeks on a holiday 24 hours a day and ended up with a 10.6MB file.
  2. HoudahGeo - the magic that inserts your geotag (location) into the photo. THe beauty of HoudahGeo is it can work with flat files (like a directory full of photos), but also directly integrates with Apple's iPhoto and Aperture. Basically it matches the time stamp on the photo to the nearest geotag recorded from the file created by your iPhone.

Step Two - The Workflow

Really, this is why I love this so much - it's so easy:

  1. Ensure your cameras are synced to the same time as your GPS. Beware of time zones on some cameras: USE THE THE ZONE rather than push around your local time zone. HoudahGeo will thank you. Geotag Photos Pro (iPhone) app has a function to show you the time in big bold print that you need enter into your camera. This time synchronisation step is important to the subsequent accuracy of the tagging later, so take a minute and get it right.
  2. Grab your cameras and iPhone, fire up Geotag Photos Pro on your iPhone and take some photos!
  3. Load all your photos onto your Mac with iPhoto, Aperture or just a directory full of photos.
  4. Start HoudahGeo, and follow the workflow in the top right: Load -> Process -> Output.
    • Load the photos into HoudahGeo (drag into the top right panel), load the GPS track from Dropbox that Geotag Photos Pro into the lower right panel.
    • Now process! This matches the photo time stamps with the GPS track time stamps. You can review and fine-tune the matches if necessary. You can even tag photos, if you know where they were taken, using a map etc. Lots of powerful tools in HoudahGeo to tag your photos. This guide isn't to show you how to use the tools, just run through the process. Email me if you want to know more.
  5. Lastly, output the tagged photos into whatever format you need (iPhoto, Aperture, flat files etc).
  6. Go crack a beer, make a coffee or do whatever you do to celebrate.

As I said earlier, you can use this technique when travelling with a group. My family and I used this on a trip to New Zealand and ended up with thousands of photos taken by all four of us, on 5 different cameras, all tagged from a single GPS track file. Easy!

The software above isnt perfect though: * Neither are free (Geotag Photos Pro USD$3.99, HoudahGeo USD$29.00) * Geotag Photos Pro doesn't log distance travelled, so if this is important (a lot of hikers want that) you might want to consider other alternatives. * HoudahGeo is very slow when integrated with iPhoto/APerture but this is more a limitation on the iPhoto/Aperture API and disk I/O limitations.


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