Slashdot Mirror
Mining EXIF Data From Camera Phones
emeitner notes that folks at the Internet Storm Center wrote scripts that harvested 15,291 images from Twitpic and analyzed the EXIF information. This reader adds, "While mining EXIF data from images is nothing new, how many people would allow this data to leave their cell phone if they knew what it contained? The source code for the scripts is also available from the article." "399 images included the location of the camera at the time the image was taken, and 102 images included the name of the photographer. ... The iPhone is including the most EXIF information among the images we found. ... It not only includes the phone's location, but also accelerometer data showing if the phone was moved at the time the picture was taken and the readout from the [built-]in compass showing in which direction the phone was pointed at the time."
No picture leaves this computer before it has been subjected to "jhead -purejpg". Something else to look out for: Image data beyond the edge of the image after lossless resizing and orphaned preview images embedded in the JPG, showing the full uncropped picture. The latter is dealt with by the "jhead -purejpg" command, the former isn't.
The location data can be very wrong. If you don't have an adequate line of sight to the sky the phone will use cell towers to triangulate. If you can't see enough of them, it will use a wifi database to guess. If you've got a crappy (or no) cell connection but a clear view of the sky it might take a considerable amount of time for the GPS to lock on.
399 images included the location of the camera at the time the image was taken, and 102 images included the name of the photographer. ...
Or, to summarize from the other point of view...
"97.4% of images did not include the location of the camera at the time the image was taken, and 99.3% of images did not include the name of the photographer. ... "
Facebook strips the EXIF data...
and then saves the photo with a filename that includes the Facebook user ID of the person who uploaded it.
Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
Individual apps require you to give them the OK to get location data, but that only applies to shots taken from the app itself and not those that pull from the existing photo library. You can turn location services off entirely, but I can't find an immediately obvious way to revoke privileges from individual apps.
How are sites slashdotted when nobody reads TFAs?