as a small block of wood, like a mouse
on the UnMouse Pad, but more interestingly one can use multiple fingers
to write and draw on the pad, creating
the corresponding content on a computer screen.
An undergraduate student of Perlin’s, for example, has used the UnMouse Pad for animation; one of the
student’s hands moved the “paper”
around on a screen while his other
hand drew on it. “You rethink how you
interact with information,” says Perlin. “It’s much more human friendly.”
The UnMouse Pad is part of Perlin’s focus on creating innovative but
low-cost technology. “Rather than use
a large number of wires and expensive
circuitry, we use a sparse set of force-sensing wires on the surface—one
wire every quarter of an inch—and
that’s sufficient,” he explains. “Our approach allows us to measure continuous position in the spaces between the
wires, using simple and low-cost electronics.”
Fortunately for Perlin and other researchers, there is now a large arsenal
of relatively inexpensive motion-sens-ing equipment for gestural and multitouch input.
The most ubiquitous touch screens,
such as ATMs and airline kiosks, measure a finger’s position as it presses a
layer of transparent indium tin oxide
that is charged from the horizontal
edges of the display to a layer that is
charged from the vertical edges. Except
for light pens that use the onscreen
image to find where the tethered stylus is, most touch sensing today requires calibration. One can imagine a
calibration-free technology that could
be integrated into flat-panel displays.
The approach could use the thin film
circuitry in the display as an array of
antennas. Modified driver chips could
be used to measure the changes to the
electrical field in patterns at different
pixel locations in the display. And software could sort the changes in a high-frequency electrical environment of
the local pixel circuits to locate where
and how many fingers are touching
the screen.
commercial success
The iPhone’s commercial success—
approximately 10 million units sold
and counting—has been a giant step
apple, microsoft,
and Perceptive Pixel,
among others, are
investigating how
to best use multiple
fingers and hands for
multitouch input.
forward for the mainstreaming of multitouch technology. “The iPhone is important,” Perlin notes, “because it tells
people that using multiple fingers to
interact with computers via hand gestures is a natural, wonderful thing.”
Bill Buxton, a senior researcher
for Microsoft Research and a pioneer
in human-computer interaction and
computer graphics, envisions a future
of multitouch devices with their own
specially designed operating systems
and applications. “One solution I
see,” Buxton says, “is that we will start
building new classes of computational devices that are not constrained by
the legacy applications that were designed for a very different style of interaction.”
Buxton believes future technology
will create new relationships between
typical consumer devices and multitouch screens. “What is really fascinating to me is when you combine the ability of not just the sense of touch of my
fingers, but when different objects—a
phone or a camera—makes a relationship with the use of my hands and gestures,” he says. “This will lead to a convergence of multitouch surfaces and
what is known as tangible computing.”
New multitouch surfaces also
mean new finger and hand gestures,
and along with the development of
multitouch operating systems and applications, Apple, Microsoft, and Perceptive Pixel are investigating how to
best use multiple fingers and hands
for multitouch input. “A lot of our research is coming up with gestures and
manipulation metaphors,” according
to Han, such as how a CAD designer
could manipulate multiple parts of an
Computer Security
Attacking
Keyboards
swiss security researchers have
developed four attacks that can
detect what a person is typing
on a keyboard by analyzing the
signals produced by keystrokes.
according to the researchers,
doctoral students Marti
vuagnoux and sylvian pasini of
the security and cryptography
laboratory at the swiss ecole
polytechnique Fédérale de
lausanne, keyboards are “not
safe to transmit sensitive
information.”
vuagnoux and pasini tested
11 keyboard models connected
to a computer via a ps/2 or usb
slot and found that each of the
keyboards was vulnerable to
at least one of the four attacks
they devised. (The attacks also
worked with laptop keyboards.)
The researchers used a radio
antenna to “fully or partially
recover keystrokes” by spotting the
electromagnetic radiation emitted
when the keys were pressed.
vuagnoux and pasini have
stated they believe “our attacks
can be significantly improved,
since we used relatively
inexpensive [equipment].”
artificial Intelligence
Human
or Not?
“am i conversing with a human
or a computer?” is a question
that a dozen judges grappled
with at the annual loebner
prize competition held at the
university of reading.
in 1950, british mathema-
tican alan M. Turing suggested
that a computer could be said
to be thinking if, in a text-based
conversation, its responses
are indistinguishable from a
human’s. Turing predicted that
by the end of the 20th century,
computers would have a 30%
chance of being mistaken for
a human in a five-minute text-
based conversation.
in the 18th loebner prize
competition, elbot, one of six
programs, nearly passed the
Turing test, tricking 25% of judges
into believing it was human. each
of the six programs fooled at least
one judge.
