If you've ever been to Japan—or seen a picture—you'd know that the entire surface of cityscapes is basically one giant advertising mosaic. So how do advertisers know which ones people actually gawk at?
Japan's NTT Communications is testing a new billboard setup in January that has a built-in pair of cameras hooked up to image detection software that determines how many people are in front of the ad, and just how many are looking at it. It doesn't try to identify individuals, or tailor the ad to specific demographics, unlike some proposed systems.
The way NTT's system works is that it compares the image of passersby to an "average Japanese face" and determines whether or not they're peeping at the ad:
"We gathered together many faces and came up with an average Japanese face, and by using pattern matching the system recognises faces from the image."