Digital Camera Face Recognition: How It Works?

Face detection technology, available from manufacturers such as Canon, Pentax and Fuji­Film, uses special algorithms to parse the scene while you aim the camera. What's it looking for? The shape of a human face, of course. When it finds one, the camera automatically adjusts both the focus and the exposure to provide the best portrait possible. In the case of FujiFilm's "Image Intelligence" system, for example, a chip inside the camera constantly scans the image in its viewfinder for two eyes, a nose, ears and a chin, making out up to 10 faces at a time before you've hit the shutter. Usually, a scanned face has to cover at least 10 percent of the height of the viewfinder LCD — this requirement prevents the camera from trying to lock on to faces far in the background. The face identification process takes about four one-hundredths of a second. You can turn off the face recognition feature for times when your subject isn't a human. However, according to FujiFilm project manager David Troy, research shows that "70 percent of images taken have a person as the subject." Face recognition can be used for more than just autofocus. Some cameras capture the location of the identified faces within each picture snapped. This lets you zoom in on the faces automatically on the camera's LCD after you take the shot — useful when checking if grandma's eyes were closed or open. Sometime soon, face detection may even give way to facial identification, discerning one subject from an-other. For instance, the camera could retain an image tagged "Mom" in its memory. Later, the camera would automatically recognize each subsequent picture of your mother and add the "Mom" tag to it. As for the question about animal faces, you're not alone in wondering how the new cameras handle our friends from other species. "You'd be surprised how often we get that question!" says FujiFilm spokeswoman Katherine Keane. "Unfortunately, FujiFilm's face detection technology can only detect human faces." So you'll just have to focus on Fido's friendly mug yourself.