"SAC currently receives video and audio input from a conventional video camera and a pair of microphones," he adds. "It takes those two stimuli and it combines them, to compute the probability that a target has appeared in the environment. And then it initiates the movement of the camera to look in the direction of that target."
A Camera That Listens
The camera has been taught to distinguish between different sounds, so it knows if a person is speaking, or someone just dropped a book.
"The human voice has a very specific audio signature," Anastasio says. "It doesn't matter who's speaking, or what language, or the age or sex of the individual, they all seem to have a particular pattern in the audio power of their speech."
So SAC knows to zero in on a person who is speaking, rather than someone who is walking around the room, because it responds preferentially to the sound of the human voice. That could come in handy some day in automated video conferencing equipment.
SAC is very limited, however, in that it has to be taught just what to look for. The next goal, Anastasio says, is to have SAC learn for itself which targets in its environment are interesting.
"We don't want to have preconceived notions of what targets to look for," he says. "We want to detect a source of new information in our environment and turn around and look at it and see what it is. It might have survival value for us. Maybe it's a danger thing."
That's a tall order, but there are more modest applications for this kind of research, and those partly explain the military's interest. The Office of Naval Research's Davis, for example, thinks an advanced version of SAC might be useful in "directing counter fire."
Armed and Robotic
A brainy camera, armed with microphones, could train a gun automatically to return the fire from a hostile source.
The camera could pick up muzzle flashes, and the microphones could detect sounds consistent with gunfire, and almost instantaneously fire back.
And the sensors need not be limited to the range of human capability. Infrared sensors, for instance, could detect the presence of a living organism, radar could detect the distance to the target, and other sensors might even be able to sniff out dangerous fumes. Then it would combine those separate streams of data and compute whether the target poses any danger.
Of course, you couldn't call this thing SAC.