Photo EXIF Data

Photo EXIF Data

More digital photos will be taken this year than were taken on film in the entire history of the analogue camera business.  Estimates vary on the total number of photos that will be shared this year between worldwide users, between 2-3 trillion depending on how you crunch the numbers.  Some researchers estimated even higher and the exact number would be impossible to know.  Sharing our lives with other people through the photos we take on our smartphones has become a daily routine.  We share our digital snapshots on websites, blogs, social media, email, and through text messages.

Many people don’t realize that a photo has a lot of hidden information in it, or they underestimate just how much information can be extracted from a digital photo.  This information is called metadata or EXIF data, and that data is embedded into the code of every photograph.  The data may include the date/time the photo was taken, the type of camera or phone used, shutter speed, flash use, and about 100 other pieces of information.   While much of this information is not always accessible by the end user looking at it (whoever views the photo on Facebook or a blog), the information is accessible to the service you upload it to.  No-one really cares about the shutter speed or flash information, but location data is important.

locservicesLocation data (GPS coordinates) can be seen in the EXIF data of any photo that was taken on a smartphone when the user had location services turned on.  Location services are “on” by default and most users never adjust this setting for their camera.  Online tools like ExifTool will extract metadata from photos, including location data.  ExifTool is a command line tool but there are many GUI tools available as well, including http://www.verexif.com which is available online for free.

There are many useful ways that photo location data can be used and I won’t go into them all in this article.  Photographers of all types utilize this data for sorting, organization, documentation, and tracking purposes, as this is handy information to have about each photo in their collection.  The uses for having accurate location data are endless and technology enables us to use this data in new ways all the time.

When taking a photo, not only is the actual GPS location captured, but also the direction the photographer was facing when the photo was taken and in some cases even the altitude information.  For example, analyzing EXIF data from a photo could reveal the precise location of the photographer, the direction he/she was facing, and the floor of the building (elevation) they may have been on when taking the photo.  Isn’t technology amazing?  By now you may have guessed that I would prefer not to reveal so much information.  I love taking and sharing photos…but I also see photographs as “evidence”.  I recognize the tremendous amount of information that can be extracted from a single digital photo and I am conscious of what I share and with whom.  I don’t think that is paranoia; just an elevated awareness of how digital photos differ from traditional photos.

Location data is most commonly revealed when you share photos via a web server, blog, through email, and messaging apps, like iMessage.  Both the recipient of your photos and the companies involved in this transaction will have your location data, and all the other data associated with that particular photo.  Larger sharing services, like Facebook, usually strip away the metadata from photos that are posted on their services.  A user viewing those photos would not be able to extract metadata from that photo, however the original location data is still available and usually collected by that company (Facebook, and others).

Unless a service deals with a huge amount of photos and processes them to work with their internal system (Facebook, Google, Tumblr etc.), the metadata can usually be extracted.  Most people worry less about photos that are emailed or sent through iMessage because you know recipient.  Remember that photos are forwarded to others or uploaded somewhere else more often than you think.  Services that are in the business of collecting and selling information like Facebook and Google, or anyone who has an interest in finding out where you are and have been, could use this information to build a very detailed profile of you.  Someone with malicious intent could use location information to see when you are out of town or away from home.  The bottom line is to keep your location information private.  If you don’t, companies will target ads based on your location(s), you will open yourself up to people with bad intentions, and your boss will be able to see that car accident photo that you sent to show why you were late to work; is not really your photo, it was taken a year ago, and was nowhere near where you claimed to have been.  You get the idea.

The best way to keep your location info hidden is by not having any location data embedded in your photos.  Turn off location services on your phone.  This will keep your camera app from geotagging your photos and will keep apps from attaching geotags when you upload something.  If you do want to keep your location information available, then you can still get rid of that info before you upload or send the photo.  Applications such as Pixelgarde can strip your photos of almost all metadata.  Every photo that leaves my computer has been sanitized by Pixelgarde or a similar app first.  Think of malicious and creative ways that someone could compromise you based on your location data, or how much someone could learn analyzing it.   For a number of reasons, keep that information to yourself.  Now…go take some more photos of your cat!

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