About Geotagging
GPSPhotoLinker adds GPS position and location data to your photos. The latitude and longitude recorded by your GPS unit are linked and saved to your photos. GPSPhotoLinker also automatically enters the city, state and country into the metadata. Adding geographic information to an item is known as geotagging [wikipedia.org].
Why geotag?
You will always know exactly where a photo was taken since the latitude, longitude, city, state, and country are saved to the photo.
Mapped web galleries
Flickr, Picasa, Locr and other websites place geotagged images directly on a map for sharing with family and friends. Check out our examples of mapped web galleries.
Queries
Using Spotlight in Mac OS X 10.4 and higher, you can easily search on any of the metadata right in the Finder. If you search for "Alaska," all photos taken in Alaska will be found because of the geographic information saved to the photo.
How it works
Linking GPS position data to photos relies on the time stamp recorded by your camera and GPS.
A typical GPS continuously records position data (track points). Depending on the GPS settings, it may record track points every few seconds or every few minutes. Track points always contain the latitude and longitude. Often the time and altitude are recorded as well as other data.
A digital camera records the time you take a photo and saves that information to the photo. Imagine you took a photo at 9:50:20 AM. Your GPS was recording track points and recorded a track point at 9:50:01 AM and another at 9:50:30 AM. GPSPhotoLinker finds these two track points, calling the first track point the "Preceding track point" and the second track point the "Next track point".
GPSPhotoLinker will generate a "Time weighted average point". Using the example above, let's say you were standing at your house at 9:50:01 AM, walked for 20 seconds, took the picture, and 10 seconds later, at 9:50:30 AM you were 30 meters away. Because the photo was taken 20 seconds after you left the house, GPSPhotoLinker calculates a point assuming you were 20 meters away from the house, called the "Time weighted average point".
Depending on your choice GPSPhotoLinker will save the "Preceding track point", "Next track point" or the "Time weighted average point" to the photo.
GPSPhotoLinker has three modes for adding GPS position data. In addition to Single mode described above, Auto mode will automatically link and save geographic information to multiple photos. Manual mode allows you to select a waypoint or track point (which may not have time stamp data) and save the geographic information to the selected photo.
GPSPhotoLinker allows you to choose between two web services for saving city, state and country data to the photo.