 say something about them.
<p><a name="geotagging"></a></p>
<h3 class="section">4.1 Geotagging</h3>
<p>Geotagging adds GPS data to your images based on data from a GPS track log file.<br>
This GPS track file can be used from your phone, gps device, navigation device, or whatever you have providing such a GPS track.<br>
The GPS track log file is loaded, and linear interpolation is used to determine the GPS position at the time of the image, then the relevant tags 
are written to the image (if the correspondi