GeoTagger - Display and modify GPS location data in photos
User Guide

GeoTagger User Guide

This User Guide shall show you how to efficiently use GeoTagger to modify the time and location data in your photos, as well as correct wrong orientations, straighten horizons or crop your images. It will also provide suggestions on how to organize your photos. For detailed information on the commands mentioned here, please refer to Help/GeoTagger Help (F1).

Organizing your photos

If you have many photos, it's probably a good idea to store them in some ordered way. Here's one way to do it:

Create a directory for your photos, for instance
MyPhotos
Create a subdirectory for each year, as in
MyPhotos/2019
MyPhotos/2020
MyPhotos/2021
For each event in a year, create a subdirectory that starts with the month and a lowercase letter, like
MyPhotos/2019/01a_Happy_New_Year
MyPhotos/2019/06a_Summer_Vacation
MyPhotos/2019/06b_Touring_the_Rockies
MyPhotos/2019/12a_Christmas
The reason for the leading numbers and letters is to have the directories sorted in the proper chronological order. Of course any other method will do just as well. Using underline characters instead of blanks may help avoid problems when accessing them from scripts or the command line, but it is not mandatory.

All of this is just a suggestion, GeoTagger works with any files from any directories.

Photos from various sources

If you have photos from various sources, like different cameras, smartphones or other people who took photos at the same event, it's a good idea to keep the original files in separate directories:

Within the directory of the event, create a subdirectory that will hold all the original files, like
MyPhotos/2019/06a_Summer_Vacation/ORG
If you have received files from different people, you may want to create a subdirectory for each of them, as in
.../ORG/Alice
.../ORG/Bob
.../ORG/Peter
Even if, for the moment, you only have files of your own, it's a good idea to introduce this level of hierarchy, so you can easily add files from other people if you get them later.
Nowadays you most likely take the majority of photos with a smartphone, but you might also have dedicated cameras for special purposes. So another directory level should be created, like
.../ORG/Peter/iPhone
.../ORG/Peter/SONY-DSC-HX90V
.../ORG/Peter/Canon-EOS-6D
Finally, copy the files from each source into the proper directory.

Again, this is just a suggestion. However, using this scheme (or something similar) can make the operations described in the upcoming chapters easier. Plus, there's always the chance that files from different sources might have the same names, so keeping them in separate directories can avoid overwriting files. Keep in mind, though, that GeoTagger doesn't require any of this - you can have all your files in a single directory and will still be able to work with GeoTagger.

GPS track files

You can put your GPS track files (if any) anywhere you like. A good place would be a directory named something like GPS or TRACKS under the ORG directory, as in

.../ORG/GPS

That way, if you load the entire ORG directory into GeoTagger, the track files will be loaded automatically.

Which mode to use

GeoTagger can work in two different modes when it comes to saving modifications you made to your photos. In store mode it writes the modifications back into the original files (making backup copies first), while in cache mode it keeps them in files named .geotagger in the directory holding the image files. The first one is the default, because this is probably what most users would expect. However, the second mode has the advantage of leaving the original files completely untouched and saving data much faster. If you just want to combine all your photos into one directory (using the File/Export (Ctrl+E) command, this mode is strongly recommended. You can activate it in the Edit/Preferences/Backup dialog.

Fixing times

The first step in consolidating your photos is setting the timestamps right.

Wrong time in camera

Let's assume that in the above example Peter's SONY camera didn't have the correct time, but was 10 minutes behind. To fix this, do the following:

File/Clear Image List (Ctrl+K)
File/Open Directories (Ctrl+Shift+O)
select .../ORG/Peter/SONY-DSC-HX90V
Edit/Select All (Ctrl+A)
Edit/Modify Date/Time (Ctrl+D)
in the dialog change the time accordingly and click OK

Now all selected photos have their time set correctly. Good thing you stored the photos from all sources in separate directories, isn't it?

Time zones

The time stored in the EXIF data of photos is usually local time at the place where the photo was taken. Even though your camera might have a setting for the local time zone, it most likely doesn't store that information in the EXIF data. To fix the time zone information, simply do as described above, but instead of changing the time, set the "Offset from UTC" to the proper value. This new value will be applied to all selected images. Note that the "Offset from UTC" is given in hours and minutes in the form +/-hhmm, and includes a possible daylight saving time. For instance, in Denver, Colorado, the offset from UTC would be -0700 in winter, and -0600 in summer.

There is also another problem with moving between time zones, which is described in detail in the chapter "Aligning times" of the GeoTagger Help.

Fixing locations

Now that the timestamps of your photos are correct, you can begin to fix the location data. Not all cameras have GPS sensors, and even if they do, the location in the EXIF data may be wrong or missing (if there was no GPS reception at the time).

Known locations

If you know where a photo was taken, just scroll/zoom the map to that point and click on the location in the map. You can also select a group of photos that were all taken at the same place, and set their location that way. See "Modifying locations" in the Geotagger Help for details.

GPS tracks

Using GPS track logs is another method of setting the location of your photos. Again, you can do this for individual photos or a group of photos. See "GPS track logs" in the Geotagger Help for details.

Interpolating locations

If you don's have a GPS track log, and some of your photos have location data, but others don't, you can let GeoTagger interpolate the locations of photos between two known points. See "Interpolating locations" in the Geotagger Help for details.

Altitudes

GPS coordinates consist of three values: latitude, longitude and altitude. Measuring the altitude is more complex than measuring the other two, so sometimes the location data of your photos may lack that value (or have it completely wrong). There are services on the Web that provide the altitude for a given latitude/longitude. See "Altitude" in the Geotagger Help for details.

Manipulating the images

The main focus of GeoTagger is, of course, setting the times and locations of your photos right. However, while going through your photos, you may come across some of them that have a wrong orientation (like portrait instead of landscape), are a bit slanted (so that the horizon isn't horizontal) or show stuff that you would like to cut off. GeoTagger can do these simple operations, so you don't need to launch some image processing tool for this. See "Rotating images", "Straightening images" and "Cropping images" in the Geotagger Help for details.

Exporting photos

GeoTagger can combine all photos from various sources of a certain event into one directory, generating new file names that contain the date and time the photos were taken, and setting their timestamps accordingly, so that any image viewer will show them in the proper sequence. In the example mentioned above, this could be

MyPhotos/2019/06a_Summer_Vacation

See "Exporting image files" in the Geotagger Help for details.

GeoTagger icon made by Nikita Golubev from www.flaticon.com