Geotagging Images for Geoengineers

Get to Geotagging

Now we’re ready to actually do the geotagging. As with most things there are multiple ways of doing this and this is by no means an exhaustive list. But I think for most users it covers the basic options they will consider. We’ll look at geotagging manually with Picasa, using RoboGEO software (commercial software package), and using GPicSync software (free). If you have a Mac, you can try HoudahGeo (commercial software package) but I won’t cover it here. If you need a solution for Linux, you’re probably a bigger nerd than I am, so you’re on your own!

The Manual Way with Picasa

The best way to learn how to do this is with a short video (about 2 min). I’m not a big Picasa user, I prefer Flickr. By the way, if you want to manually tag photos in Flickr, check out this cool bookmarklet.

The Best Way – RoboGEO Software

When I say "best way", what I mean is that RoboGEO is the best way I’ve found so far. The only drawback is it’s not free, the personal license is $40, commercial license is $80 and a 10-user commercial license is $400. But on the plus side, once you buy a license, you get free upgrades for life. They seem to have some kind of activation, so don’t think you’ll be able to install it on multiple computers without the appropriate licenses. Assuming you decide to purchase the software, I have a sequence of screenshots to walk you through how the process works.

After starting RoboGEO, check the Preferences to see if you need to adjust anything, including the camera offset which helps if you ignored my suggestion to synchronize your camera and GPS clocks. Then you’re ready to load your photos for geotagging (Figure 3).

Figure 3: Select images in a folder

Once you do that, it should look something like Figure 4.

Figure 4: Photos loaded

Now we need to add the GPS data by importing the GPX file you created (see Figure 5).

Figure 5: Import a tracklog file

Once you import the tracklog, you’ll see that all of the lat/long/alt fields have been filled in (Figure 6). But you’re not done yet!

Figure 6: Photos tab after importing GPS tracklog file

Click the button shown in Figure 7 to write the coordinates to the EXIF headers of the image. Then the coordinates become a part of the JPG file and can be used in any application that respects the EXIF headers.

Figure 7: Write data to EXIF headers

The best way to distribute your geotagged photos for casual browsing in a geographic environment is to export them to Google Earth by clicking on the appropriate link (Figure 8).

Figure 8: Export to Google Earth

Figure 9 shows the Google Earth export interface from RoboGEO. You can adjust the image title (used for the placemark name) and add a description to be displayed when the image thumbnail or icon is clicked.

Figure 9: Google Earth export interface

Probably the biggest decision you have to make in this process is the file format (see Figure 10). KML is now an open standard file format that can contain things like placemarks, shapes etc. To display an image, you basically use HTML inside the description of the placemark denoting the image location. RoboGEO handles all the nitty gritty of creating this for you.

A KMZ file is basically a KML file that’s been compressed in the same way a ZIP file is compressed. In fact, if you change the file extension of a KMZ file to ZIP it should open up to show the KML file and sometimes other files. In this way, a KMZ file can actually contain images. Using the KMZ w/images format will do this for you, but watch out. The file size can get rather large if you have many images and you make the sizes large. Despite the potentially large file size, this format is the easiest way to distribute your images for someone to look at in Google Earth, there’s only one file to worry about. If you are only sharing the files with people in your office and the photos are stored on the network, KML or KMZ should work. If you have space on a webserver, you can publish the photos to a folder there (like by using FTP) and select KMZ for the web and fill out the field to point to the correct folder on your webserver.

Figure 10: Type of Google Earth file to output

Once you click the create button, open up your file and try it out! In Figure 11, each camera icon corresponds to the geotagged location of the photo. You can change the preferences in RoboGEO to output a thumbnail image of the photo instead of the icon if you want.

Figure 11: Google Earth screen capture

When you click on the icon, you can see the larger size image complete with the title and description you specified (Figure 12).

Figure 12: Viewing geotagged photo in Google Earth