In late 2010, Microsoft chalked up a Guinness World Record for
the fastest selling consumer electronics device with the Kinect -- a motion sensing controller for the Xbox 360.
Andrew Blake from Microsoft Research in Cambridge was part of
the team that built Kinect, and he took to the stage at Wired 2011to talk about the
history of computer vision, and how difficult it is to make a
computer see in the same way that a human does.
The field began in 1966 as a summer research project handed out
to a student. It was thought that it'd take a few months, but it's
been continually worked on by academics for more than 45 years and
it still isn't perfect.
The difficulty is that computers tend to take things literally.
They see an image as a field of numbers, whereas humans approach
image recognition in a totally different, probabilistic way --
"It's like our brains are professional statisticians running around
trying to make sense of the world," said Blake.
The first vision technology to gain much in the way of traction
was face recognition. A team fed a computer a series of faces and a
series of things that weren't faces, and got the computer to try
and form hypotheses about how much something looked like a face.
The locations with the highest probability were tagged, and the
rest were discarded.
That proved commercially lucrative, especially with camera
manufacturers, and the field has now moved on significantly.
Computers have been trained to detect when people have sunk
suspiciously in swimming pools, and panoramic photos can now be
automatically stitched together with an impressive success
That stitching technology has been taken far further with
Microsoft's Photosynth project, which
can switch thousands of photographs of the same object taken from
different angles under different lighting conditions, and stitch
them together into a three-dimensional representation of that
Human pose estimation, in the form seen in Kinect, is a trickier
problem still. The way they cracked it was to see the human body as
a cluster of objects, each with different but recognisable
properties. Faces have a nose, eyes and a mouth. Arms are long with
fingers on the end, etc.
But the team haven't just been sitting with their feet up since
the device was released. Giving what could be a glimpse into the
future of the platform, Blake pulled Wired magazine's editor, David
Rowan, onto the stage and asked him to sit on a stool, then scanned
him with a Kinect sensor. Within moments, a three-dimensional model
of David had been built up. "Now we can send him to a 3D printing
lab, perhaps get a bronze David".
With this type of power in the labs today, it might not be long
before your scanned three-dimensional avatar stars in the next game