The Adobe Photoshop Lightroom 3 Book: GPS Metadata and Lightroom
From the book
From the book
From the book
GPS metadata and linking to Google Earth™
If you have GPS metadata embedded in an image file, Lightroom will let you link directly to the Google Maps™ Web site and locate exactly where that photograph had been taken. But in order to pull off this trick, you will need to find a way to embed GPS metadata in your image capture files. This is not as difficult as you might imagine, since there are now quite a few GPS devices capable of capturing the GPS coordinates at the time of capture and then synchronizing the GPS data with your capture images via post-processing software. For example, according to John Nack's blog, JOBO AG has announced photoGPS, a $155 device that sits in the hot shoe (the mounting point for a flash) of a digital SLR. Post-processing software synchronizes data captured by the device with the corresponding images. In the following steps, I have used an image with embedded GPS metadata to demonstrate how Lightroom can use such metadata to link to Google Maps as well as how to view the location using the Google Earth program.
- Here is a Library view of photographs shot around Dorset, including a highlighted photograph that was shot looking toward Ballard Point near Swanage, England.
- In this Library module view, you can see the Metadata panel is in the All view mode. If GPS metadata is associated with a photograph in the catalog, the GPS coordinates are displayed with an action arrow Map Location button next to the item in the Metadata panel. Note: If no GPS data is associated with a selected photo, this GPS field remains hidden.
- Clicking the Map Location button takes you directly to the Google Maps Web site, pinpointing exactly where the photograph was taken (providing you have a live Internet connection). If Google Maps allows, you may be able to zoom in to get a closer look at the location where the photograph was taken.
- If you have the Google Earth program installed on your computer, you can copy and paste the GPS coordinates and use the program's extensive navigation tools to explore the scene where the photograph was taken. Here, I tilted the preview to show a ground-level view from where the photograph was shot.
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How to embed GPS metadata in a photo
OK, now that I have shown you how GPS metadata can be useful, let's see how you can capture and embed GPS metadata in a series of photos. Lightroom does not have any mechanism that will allow you to import or edit GPS metadata. In fact, it will only display the GPS field in the EXIF Metadata panel if GPS metadata is actually present in the catalog image files. The following steps show how I was able to import the GPX data from an AMOD AGL3080 unit (see Figure 4.88) and merge the GPX data with the camera-captured images. This small device can record the GPS coordinates of wherever the unit is, several times per minute, and record the GPS time-stamped trackpoints to a log file. When you get back to the computer, you'll need to use one of the suggested programs described here to read the GPS log data and merge the data with the imported photos.
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Figure 4.88 The AMOD AGL3080 GPS Photo Tracker is a small, lightweight device which can be used to record GPS coordinates that can be read by the appropriate software. It is easily attached to a camera bag strap.
There are a number of software solutions you can use, and when you purchase a GPS geotagging device, you may well find it comes with software that is supplied free for Mac or PC. The problem here is that many of these programs are designed to write GPS data to JPEG capture images only. What's really needed is software that can write GPS data to .xmp sidecar files, from which you can read the updated metadata via Lightroom. For this edition of the book, I thought I would update things by highlighting two popular programs: one that's suitable for PC users and one that's for Mac only.
GeoTagging with GeoSetter for PC
The following steps show how I used GeoSetter to tag raw images with GPS coordinates recorded using the AMOD GPS tracker device. GeoSetter is available free from www.geosetter.de/en/, but don't forget to make a donation if you find this software useful.
- I connected the AMOD GPS device via the USB cable that came with the unit. The AMOD device has room to store lots of GPS data, but it makes sense to back these up to the main computer as soon as you can. Once the GPS log files have been copied and backed up, it is safe to delete them from the device.
- Next, I launched the GeoSetter program for Windows Vista. I targeted a folder of images and loaded the copied GPS files that were associated with this particular folder. (You can see here, outlined in red, some of the routes that were recorded by the AMOD GPS device.) Normally, you can select all of the photos from a shoot and add GPS data to all the selected photos, but in this instance, I wanted to show what happens when a single photo is processed. So I selected just the one photo shown here and used the
command to add GPS data to the selected image.
- Here, you can see the Synchronize with GPS Data Files dialog. This allowed me to fine-tune the time settings before applying the GPS data. For example, I selected the Interpolate option, and GeoSetter read the previous and next track-points and calculated where between these two points the photo was most likely shot. Are you sure that the camera's time setting is accurate? You can compensate for any time difference between the time recorded by the GPS device and the time embedded by the camera's internal clock, whether there is a simple error of a few minutes or the time zone is incorrect.
- When I was happy with the synchronize GPS settings, I clicked OK. This opened the dialog shown here, where I could click Yes to apply the GPS data to the selected image.
- The GPS data had been synchronized in GeoSetter using the nearest track-point recorded by the GPS device, and you can see the GPS coordinates in red just below the image thumbnail. The estimated position the photo was taken from is also represented with a pin icon in the Map view panel section. At this stage, I needed to save the GPS data to the file's metadata so that the GPS coordinates could also be read by Lightroom. To do this, I highlighted the photo and used the
command shortcut. Here you can see that I had to click OK in a dialog asking me to confirm that I wished to use the current system date zone setting.
- I now needed to synchronize the file metadata in Lightroom. To do this, I went to the Library module and chose the Metadata
Read Metadata from Files menu option. At this point, Lightroom realized that this step might lead to a potential conflict in which, under some circumstances, you might end up overwriting important metadata information. For example, suppose you had edited one or more of your photos in Camera Raw via Photoshop or Bridge. If you were to choose to read metadata from files, this might mean overwriting some or all of the edits you had applied in Lightroom (see sidebar). In this example, I knew that it would be safe to read the metadata, knowing that all this would be the recently updated GPS metadata. Once this last step had been completed, the Map Location link appeared in the Metadata panel EXIF metadata list, and I could click the Map Location button (described on page 203) to view the Google Maps Web page.
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I recommend you consider carrying out a Metadata Save of all the images you are about to process before you open the files in GeoSetter (or the HoudahGeo program that's described in the next section). Select all the photos first and use
(Mac) or (PC) to save the current file metadata settings. Then you'll be ready to process them in a GPS linking program.
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GeoTagging with HoudahGeo for Mac
Mac users will find HoudahGeo (www.houdah.com/houdahGeo) is an easy geotagging program to work with. In demo mode, you can use this software to process up to five images at a time, but to batch process any more than this, you will need to purchase the full licence.
- In this first step, I opened both HoudahGeo and Lightroom and, with the Library catalog in Grid view mode, simply dragged a selection of imported photos across to the main HoudahGeo window. At this point, it is worth cross-checking the time shown here with the time shown on your camera to make sure they are in sync and to compensate for any time difference so as to achieve a more accurate syncing of your photos with the recorded GPS data log.
- Here you can see a list of the camera files that had just been imported. I then clicked the "Load GPS data from file" button and browsed to locate the GPS log to link with the images. (I discussed copying the GPS logs from the GPS device on page 204.)
- The unlinked image files remained colored orange, but the updated image files now appeared in black. At this stage, I needed to click the "Write EXIF/XMP/IPTC tags" button (circled) to sync the GPS data with the image files. In this dialog, all I really needed to do was to ensure that the "Tag masters / originals" option was checked.
- Meanwhile, in Lightroom, it was essential that I kept the exact same image selection active and chose Metadata "Save metadata to file" () before I went to the Metadata menu again and chose Read Metadata from Files. It appears that an initial "Save metadata" command is necessary to ensure that the HoudahGeo-edited data is updated to the files before you read from them again in Lightroom.
- Finally, I checked to see if the metadata information had been updated correctly by selecting one of the images and checking the status of the Metadata panel. If the geotagging had been successful, I would have seen the GPS data appear directly below the EXIF Lens data and Artist items.
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