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RSSGPS Tagging in ImageIngesterPro
Updated June 13, 2007
Starting with Mac version 2.3.01B6 and Windows version 2.3.01B6, ImageIngesterPro now has the ability to read in GPS track points and write GPS tagging (latitude, longitude, and altitude) into ingested files.
A new GPS Data panel, which you open from the Tools menu, can get GPS data from a GPX file or from Garmin or Magellan devices. Once you input the data, ingested image files are automatically tagged in their EXIF metadata. (Technically, the tagging goes into a GPS IFD (image file directory), rather than into the EXIF IFD, but the GPS data is conventionally called EXIF metadata.)
Because the GPS tagging is written into the image file, rather than only into a sidecar, the resulting images are compatible with any software that expects GPS metadata, including Bridge, Photoshop, iView Media Pro/Expression Media, Lightroom, or any web site that deals with geography (e.g., Flickr or SmugMug).
Actual reading of the GPS data is done by GPSBabel, which is a common approach used by many apps, such as Google Earth. You don't have to install GPSBabel, as it's included in the IIP installation.
As is done by most other tagging programs, IIP interpolates between track points based on time. If you move the device while it's off, and take a picture while it's off, this interpolation is likely to be off, too. But, if the device is on and you're moving slowly enough to actually shoot, the location will be very accurate.
Actual writing into images is done by ExifTool, which is also includedin the IIP installation.
What images get tagged depends on whether you have a pre-conversion backup or not. If you do not have one, that means the first copy of the card is made to the primary folder, and so the images there are tagged. JPEGs and many raw formats are supported by ExifTool, but some are not (e.g., the RAW files from a Panasonic Lumix DMC-LX2). You'll see an error message if a raw file can't be tagged.
If you do have a pre-conversion backup, whether you're converting or not, the images in the pre-conversion backup folder aren't tagged, just those in the primary folder. Therefore, converting to DNG is a good way to get images tagged if ExifTool can't support your raw format. In this case, you should keep a copy of the GPX file, since the untagged backup images may be useless without their GPS tagging. (A later IIP release will save the GPX data automatically.)
In all cases, if you have a post-conversion backup, those images are tagged, since they are a copy of what's in the primary folder.
Tagging adds time to the ingestion, because ExifTool is fairly slow. However, it has an excellent reputation for reliability, so I'm likely to keep using it unless technical problems (other than speed) arise.
Sometimes ExifTool reports a minor error, but the resulting images and the entire ingestion are OK, as in this example:
ERROR processing /Volumes/External/Temp/PrimaryTest/7136-7136/L1000568Leica Camera AGM8 Digital Camera-0.dng: Error: [minor] Bad MakerNotes directory pointer for tag 0x311 - /Volumes/External/Temp/PrimaryTest/7136-7136/L1000568Leica Camera AGM8 Digital Camera-0.dng
GPS Tagging:
0 tagged
0 out of time interval
1 error(s)
An error from GPS Tagging isn't considered to be an ingestion error, so in this case IIP continued and reported the ingestion as successful. This means that you have to look at the results of the GPS Tagging in the main-window log—you can't rely on the result from IIP to tell you if the tagging went OK.
The "out of time interval" count is the number of images that couldn't be tagged because their EXIF datetimes didn't fall within the time interval convered by the GPS track points. Of course, it's important to have the camera's clock set correctly, to have the GPS device on and tracking while you shoot, and to input the right data from the device when you ingest. (If you're stationary when you shoot, the camera's clock can be off by a minute, or even longer, depending on how often you move. But, if you're shooting from a moving car, the camera time has to be exact, or else the position will be off by 50 or 100 feet or more, depending on how fast you're moving.)
If the camera's clock isn't set correctly, there are controls on the GPS Data panel to correct the times as they're read in. See this ImageIngester Blog entry for details about how this works.
I did my testing using the only device I have, a Garmin 60CSx, which might be the best device you can get. I have no idea how well IIP works with less precise devices or those that might record erroneous track points. Right now, there's no sanity checking on the track at all; it might be a good idea to toss out points that are not on a fairly smooth path. I'm very interested in feedback from anyone with a Sony GPS-CS1, since that device is fairly cheap. IIP (GPSBabel, really) can't read the Sony directly (as far as I know; tell me if it works for you), so you have to record a GPX file and transfer it to your computer. (You can ingest it with IIP if you like.) If the Sony won't record a GPX, or won't transfer one, or somehow won't work or isn't convenient, somebody please tell me and I'll buy one and get IIP working with it.
Please view the new GPS Tagging feature as experimental until a few people have tried it and had success with it. Some user-interface niceties are still missing, such as the ability to cancel executions of ExifTool in progress.
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