Sharada Prasad

I am a strong believer in location information. What is the point in talking about an issue, community or anything for that matter if we cannot pinpoint their location on Earth?

Geotagging^W is, simply said, tagging location information to an object – the object could be an image or a post office. But geotagging^W in photography is picking up since the entire process of capturing the location information (latitude, longitude, altitude and orientation) has been simplified since it can be directly written into EXIF^W data of the image.

I am a big fan of geotagging and the next few paragraphs I want to explain how to geotag photographs and create history

As I said earlier, geotagging photographs means associating location information with a photo. So there are two components here

1. Photo
2. Location information

How can we bring these two things together?

Photo – Any digital camera should help you to take a photo.

Location – You can either use your own GPS^W or if you can identify the location on a google/yahoo map, you can get the location information.

But how can we stitch these two? There are may ways to do that.

1. If you know the exact location of the picture you took, you can upload the photograph on Picasa or Flickr and use the map option to associate the photo with a location.

2. If you are taking pictures everywhere on earth and want to store location information realtime into the EXIF data of the photo, you need a camera that can interact with a GPS^W in realtime.

There are many cameras that allow you to communicate with a GPS in realtime. I used Nikon D300. Bt even Nikon D200 and several Canon cameras allow you to interact with a GPS^W. The issue with Canon cameras is that they need you to use a bluetooth enabled/wireless enabled GPS and you also need to buy a bluetooth/wireless adapter for the camera.

Nikon D200 and D300 allow you to interact with a GPS using a cable. It is cheaper and requires fewer batteries. I chose Nikon D300 over D200 since it allows me to even capture the orientation (the direction in which I take the photograph). Orientation is important since location can tell you that somebody captured a lake at a particular point… but if the lake has dried up when you visit it next time, you have no way to know in which exact spot it existed. So NE, 169 degree etc. add lot of value to orientation. Some cameras /GPS do not capture altitude information. But if you have lat/long, you can always get the exact altitude of that location through google maps. Also, the algorithm GPS use to provide altitude information is based on barometric variation and i not always accurate. Only GPS^W with builtin electronic compass enable you to capture orientation.

I used Garmin GPS GPSMap76Csx with Nikon D300 for realtime geotagging.

3. If you don’t want to buy a costly DSLR, you can still geotag pictures. But it requires some amount of post processing. First, you need to sync the time of the GPS and the camera. Then, you should set the GPS to log the track. A track log is a set of points the GPS records at specific intervals. Later, you need to put your pictures and tracklog on to a computer and use a free/paid geotagging software to locate the nearest co-ordinate from the tracklog for the date stamp on the picture and write it on to EXIF data. It is a 5 minute task for the entire set of pictures. Once you write the location info to EXIF data, Picasa or Flickr can read the EXIF data and show the picture at the exact point on the map…

You can even upload your GPS track on websites such as EveryTrail and sync it with your Flickr account to create a good visualization of your trip.

4. Now there is now a new and much simpler way of geotagging. Nikon has released a camera with builtin GPS. It is Nikon CoolPix P6000. The camera is a highend point and shoot camera and allows you to record location information realtime. No hassles with cable, extra GPS cost or any post processing. The only issue is, you cannot create track logs. Track logs are not always essential unless you want to share it with someone. If you take pictures in Cubbon park, why do you need a tracklog to show people how to reach cubbon park? But your children will always know where they had their favourite ice-cream – 50 years down the line, without you telling them…

Yes, writing location info in EXIF data is as good as creating a historical document. Nobody needs to get any information about how to reach the waterfall in the photograph. The location is embedded in the photograph

References:

1. http://www.wildportraits.com/gps.aspx
2. http://www.microsoft.com/windowsxp/using/digitalphotography/prophoto/gps.mspx (alternate link)
3. My geotagged images on Flickr
4. My GPS Tracks on EveryTrail
5. List of Free GeoCoding Software
6. My other posts on Geotagging

My 13 minute talk – Is geotagging the future of mapping? on Blip

PS: BTW Ricoh Caplio 500SE is not a camera with in-built GPS. It just supports pairing with a GPS through wireless/bluetooth technology.

This entry was posted on Wednesday, June 10th, 2009 at 2:55 pm and is filed under GPS, Photography. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.