Japanese site Egami spotted a Canon patent to obscure EXIF-information and protect your privacy. This is a particularly sensible issue if considered with regard to social networks like Facebook. EXIF data contains lots of information you may not want to deliver to the world, as geographic location, dates and time. These information allow everyone to know where you have been and when you were there (and which camera you used :-) ). Two kinds of EXIF outputs are discussed: high accuracy and low accuracy. High accuracy EXIF data is the usual data. The “low precision” EXIF data is obtained by obscuring some of the information. For instance “if the information is numeric, the digit of the lower [digits is] cut off“, and in case of alphanumeric data some of the characters will be hidden. Another way is used to obscure dates and times. As the image below shows, an exact date-time information is made fuzzy. Look at the time: from 9:45:13 it becomes a range (between 9:00 and 10:00)
A similar operation is done with GPS data. The geographic information is made more vague. In the picture below, the exact position is transformed in somewhere inside the dotted lines.