GPS And Digicams: The article I hoped to write

by John Sequeira

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David Goldwasser describes the technique of matching GPS data with digital photos. It's such a simple idea, but with enormous potential.

I see the ability to join this data to your geocoded address book as an important next step in navigating through the huge numbers of photos digital cameras produce. Location tagging helps you find photos that might only have date stamps for metadata (hmmm, what year did we visit the lake?), and helps the people who you met at a party dig up the photos when they visit your photo web site. Now that I have four years of digital photos (about 8,000 photos, mostly friends/family), this is rising high on my wish list.

In general, I like the idea of using improved photo metadata to facilitate photo finding and sharing, and it's something I'd like to see discussed and implemented more. For example, I've long believed that the facial recognition companies are missing out on a great PR opportunity by not providing home editions for amateur photographers. Can you really think of them as big brother when they help you find photos of your .... uh ... big brother ?


2004-06-16 10:02:18
Anyone else doing this?
I got hooked on GPS when I had to use it for the military, and I have some GPS coordinates (in the military grid system) for some of the pictures I took.

Now that I'm back in the real world, I'm curious about doing this. I'd appreciate any comments anyone might have about which GPS receivers work with which cameras and so on. I see a lot of general information, but I'm ready for some specific use reports.

2004-06-17 02:43:23
Anyone else doing this?
my guess is you'd need a pretty highend camera.
After all, the initial target audience would be people like surveyors and law enforcement.

At the moment I know of 1 camera with 802.11 wireless LAN as an option, that's the Nikon D2h.
It will let you write out the photos you take directly to a computer or other storage device over wireless network.
Couple that with an 802.11 equipped GPS unit which is asked for location by that computer on receiving a new image, write a small application to tag the image with the data and you should be set.

2004-06-17 06:23:06
Anyone else doing this?
There aren't necessarily camera requirements to do this type of photo-geoencoding. Why? Well, most GPS's can store a tracklog... mine looks like this:

Track ACTIVE LOG 002 10/29/2003 1:17:55 PM 00:14:17 0.205 mi 0.9 mph

Header Position Time Altitude Depth Leg Length Leg Time Leg Speed Leg Course

Trackpoint N42 22.334 W71 06.159 10/29/2003 1:17:55 PM 292 ft
Trackpoint N42 22.293 W71 06.131 10/29/2003 1:18:15 PM 292 ft 281 ft 00:00:20 9.6 mph 153° true
Trackpoint N42 22.295 W71 06.138 10/29/2003 1:19:06 PM 278 ft 33 ft 00:00:51 0.4 mph 298° true
Trackpoint N42 22.402 W71 06.206 10/29/2003 1:28:18 PM 54 ft 719 ft 00:09:12 0.9 mph 335° true
Trackpoint N42 22.402 W71 06.201 10/29/2003 1:28:39 PM 52 ft 23 ft 00:00:21 0.8 mph 90° true
Trackpoint N42 22.405 W71 06.206 10/29/2003 1:32:12 PM 59 ft 28 ft 00:03:33 0.1 mph 304° true

The programs mentioned in David's article will compare photo timestamps with this file and assign a longitude and latitude. For the friends/family/party shots that I mostly take, I just turn on my eTrex Legend when I hop in the car to go somewhere. I then have a tracklog ending at my friend's house. When I leave, I do the same. If you stitch the two tracklogs together, there's a large period of time where I'm at the destination -- a period of time that corresponds with all the photo timestamps on the photos I took. The accuracy requirements for this type of encoding are much less than say wandering around a city or desert. In fact, I could probably do the geocoding if I just wrote in my appointment book whose house I was going to on a certain day.

In any event, I suspect that at some point when people realize how useful this is, camera will come bluetooth-enabled, so they can grab coordinates from either a GPS unit or (more likely?) your cell phone's e911 circuitry - which uses either GPS or tower triangulation.

2004-07-08 07:27:26
Anyone else doing this?
In Japan one of the three major mobile carriers, AU ( in Japanese), has GPS enabled mobile cameraphones available to everyday users. The unit that I use is by Casio on the AU network, and it includes 2 Megapixel camera w/ GPS( in Japanese).

Here's a link to a recent project that grabs GPS info out of the EXIF of the JPEG from the phone (keitai in Japanese) and maps it to a 2D satelite image of Tokyo.