GPS photography adds location to digital photos

GPS photography is a huge help in photo archiveing. GPS can tell exactly where a photo has been shot. With the GPS coordinates written into the photo, it can always be found by location and been shown on the right spot on a map or satellite imagery.

The ideal solution

The ideal GPS photography solution would be to take photos with a digital camera with incorporated GPS receiver that automatically writes the GPS coordinates into the photo's EXIF header, together with all other information.

In May 2007 we only know the Ricoh 500SE GPS that has a GPS receiver incorporated and automatically geocodes all photos that are taken with this camera. However the price tag of this camera makes it "for professionals only". In the near future more and more digital cameras will have this feature.

Cameras that can read GPS data from a separate GPS receiver

The Ricoh Caplio Pro G3 can use either a Compact Flash GPS, or it can communicate with an external Bluetooth GPS receiver, using a Compact Flash Bluetooth card. This is a practical GPS photography solution, as the photographer does not have to manipulate two separate devices; the camera and a GPS receiver.

Some digital cameras from Nikon (D2X, D2Hs and D200) and from Kodak (DCS Pro series and the DCS Pro 14n) can connect to a separate GPS receiver by means of a special cable. Needless to say that this does not add to the photographers freedom of maneuverability.

GPS dataloggers for GPS photography

Sony has released a GPS datalogger, the GPS-CS1KA, to record your exact positions when you take photos. It is a small device with a carabiner, that can be fixed on a backpack or as high as possible on your clothes. It records your location every 15 seconds and with only one AA alkaline battery it does so for about 10 hours.

After the shooting session you load the photos to your computer and launch the Image Tracker software that comes with the GPS-CS1 and connect the device via the supplied USB cable to your computer. With some clicks the software compares the time stamps in the photo EXIF headers with the time stamps in the registered GPS track logfile and adds the correct longitude and latitude to the EXIF headers of each photo.

The Jelbert GeoTagger is a compact device, smaller than most flash guns, that uniquely connects to the camera's flash shoe. However it does not have a GPS receiver incorporated. Instead you will have to buy a separate Garmin Geko 301, which also houses an electronic compass and can be fixed on the GeoTagger.

Every time a photo is taken it receives a signal via the flash shoe and records longitude, latitude, magnetic compass direction, time and date to the built-in SD Flash memory card. It does not come with any software neither. Geocoding your photos must be done with a third-party software such as RoboGEO.

A very neat GPS photography solution

The JOBO photoGPS, to be launched in the Summer of 2007, fits in the hot-shoe of a SLR camera. Nothing special here. What it makes so extra-ordinary is the NXP Software's swGPS SnapSpot technology. The system sleeps most of the time and consumes almost no power, running for upwards of a year on a single lithium coin cell.

As soon as the photographer takes a picture, the system wakes up in one tenth of a second, takes a digital snapshot of the raw GPS data, saves this information to its memory and falls asleep again. It does not do the usual heavy computations to determine its location from the GPS data. These are done later on a PC or Mac computer.

Back home, the photographer uploads these data and his digital photos to his computer. The client software queries a NXP server that continuously logs the detailed ephemeris data for all 32 GPS satellites, and it calculates the exact longitudes and latitudes for all spots where a photo has been taken, and writes this information to the EXIF header of each photo.

But it does more. It translates all the lat/lon pairs to the actual country, city, street and nearest point of interest. It writes this information to the IPTC header of each photo. This is called geotagging. Any program or Internet photo sharing service that is able to read this information will give you the opportunity to find, in one single search, all your photos, taken in the same country, or the same country AND the same city, or the same country AND the same city AND the same street. This is GPS photography at its best.

Do-it-yourself GPS photography

Any device that logs a GPS track in combination with any digital camera that writes time and date to its photo's EXIF headers can be used to finally get the longitude, latitude and altitude information in the EXIF header of each photo. Third-party software compares the time stamps in the GPS track log with the time stamps in the photos and completes the information in the EXIF headers.

This requires, of course, that the two time scales run in parallel. Any GPS track log will record the time as UTC time. So, why not set the camera's clock to GMT (=UTC) all the time? If you take photos, while standing still, one or two seconds difference will be of little importance, but when a passenger takes photos from within a fast driving car, a one second difference between the two clocks can locate these photos by as far as 50 meters from the actual location.

Most programs will ask the GPS track log file to be in the GPX format. For Windows there are WWMX Location Stamper, RoboPhoto, JetPhoto Studio, Quakemap, TopoFusion and last, but not least, RoboGEO. For Mac OS X: HoudaGeo, PhotoGPSEditor, GPSPhotoLinker and GPS Automator Actions. As webservices we know of GeoSnapper and Thingster.

For our castle tours we used the do-it-yourself method.

See your GPS photography results on the Internet

Once you managed to write the latitude/longitude info to the EXIF headers of your photos, you can upload your photos to services like Panoramio, Flickr, Picasa, IsWhere or Zoto. They project your photos on a map or satellite images and you can share this with other users and see their photos, taken in the same region as where you took yours. Other programs, like RoboGEO, allow you to export your photos and tracks to the KML or KMZ format, so you can see them in Google Earth or Google Maps.

Return from "GPS photography" to the "Articles" page