A14
NEWS
The New Zealand Herald ★ Friday, July 2, 2004
Catching the best action in half the time
a goal is scored as a result.
The Florence team has not yet worked
out how to enable the computer to determine when a goal is scored in open play.
Ahmat Ekin, a computer scientist
from Rochester University in New York,
may be close to solving that problem.
He has designed software that looks
for a specific sequence of camera shots to
work out whether a goal has been scored.
For example, player close-ups often
indicate a gap in play when something
important has happened, and slowmotion footage is another useful cue.
If Ekin’s software sees a sequence of
player close-ups combined with shots of
the crowd and pictures in slow motion
that lasts between 30 and 120 seconds, it
decides that a goal has been scored, and
records the clip in the highlights.
But it could also be possible that a controversial incident is being analysed, and
Ekin aims to get round this by combining
sound analysis with the pictures to give a
more accurate result.
For example, the software could hunt
for the commentator’s extravagant shouts
of ‘‘gooooaall!’’.
The electronics giant Sharp is trialling
a simple highlights package called
Himpact with sports broadcasters. For
soccer it simply searches for all replay
footage, but in American football or baseball it captures all the plays — the action
between the frequent pauses.
In tests it has cut an hour of American
football down to around 14 minutes, and
an hour’s baseball to 10 minutes.
Sharp is now seeking commercial
partners to develop the technology for
home video recorders.
SOFTWARE: A new system cuts out the middle
men in compiling top sports moments
ONLY AT ONLY AT ONLY AT ONLY AT
Software that can identify the significant
events in live TV sports broadcasts will
soon be able to compile programmes of
highlights without any help from people.
The technology will save broadcasters
millions of dollars in editing costs and
should eventually lead to new generations
of video recorders that will let people
customise their own highlights packages.
But developing software that understands sport is no easy task. Picking out
the key events from a game — whether it
be pool, rugby, baseball, soccer or basketball — is labour-intensive.
As the footage streams into a TV
station or outside-broadcast truck, a
sports editor has to watch the action and
keep notes on what happens and when.
Only after that are the clips retrieved
and put together to form a highlights
package.
But as sports follow fixed rules, and
take place in predictable locations, computers ought to be able to pick out the key
pieces of play and string them together.
‘‘It is a situation that is ripe for automation,’’ believes Andrew Kilner at Sony
Broadcast in the English town of
Basingstoke, which makes TV broadcasting equipment.
Anil Kokaram and colleagues at Trinity College in Dublin are among the teams
trying to turn the idea into reality.
They have decided to analyse tablebased ball games such as snooker and
» Real playing time
■ One hour of American football footage
can be cut to 14 minutes of action.
■ An hour of baseball coverage can be
cut to 10 minutes.
pool — sports a computer should find easy
enough to handle because the action is
slow, lighting is consistent and cameras
mostly shoot from fixed positions.
The Trinity team’s PC-based software
uses the edges of the table and the positions of the pockets to work out where the
balls are on the table. The software has
the rules of the game programmed in, so it
can track the moving balls and work out
what has happened.
For example, if a ball approaches a
pocket and then disappears from view,
the program assumes it has been potted.
By working out how to detect foul
shots — when a player hits the wrong ball
— the team hopes to find a way to create a
compelling highlights package that
includes a varied selection of the action.
Sports like American football and soccer will be much more of a challenge,
because they involve a far greater number of moving objects (both teams of
players plus the ball) on the field which
cannot be tracked easily without huge
computer power.
Hampering this process, too, is the fact
that the colour of the playing field is often
BUSY: American football will pose more of a challenge for the program, because the large
number of moving objects requires greater computer power.
PICTURE / REUTERS
patchy and can vary with the weather and
lighting. So when the camera moves
across the field, the software could mistake the different-coloured patches for
extra players.
Carlo Colombo and colleagues at the
University of Florence in Italy found they
can compile highlights from soccer footage without tracking the ball or the moving players. Instead, one of their tricks is
to look at the position of the players in set
pieces like corners, free kicks and
penalties.
Their software detects the position of
the pitch markings in a shot to work out
which area is in the frame. Then, by
checking the positions the players adopt
in relation to the markings, the software
can decide if a player is about to take a
penalty, free kick or corner, and whether
— NEW SCIENTIST
Team predicts traffic
snarl-ups in advance
TRAFFIC: A sophisticated computer program
tracks driver behaviour with more accuracy
by Justin Mullins
A traffic simulation system is helping
drivers by predicting jams on Germany’s autobahn network up to an
hour before they happen.
The secret of its success is to take
into account the way real drivers and
their cars behave.
When engineers model the way
road traffic flows they break the traffic
down into three categories: freely flowing, jammed, and an intermediate state
called synchronised flow in which
dense traffic moves in unison, like
marchers moving in step.
But this synchronised flow is unstable. One car pulling into another
lane and forcing the driver behind to
brake hard is enough to start traffic
bunching up.
This can quickly develop into a jam
that propagates backwards through
the traffic like a wave.
Failure to predict this ‘‘pinch effect’’
has stymied past attempts to model
traffic flow.
Now Michael Schreckenberg and
colleagues at the University of Duisburg-Essen in Germany have developed a computer model that successfully reproduces the pinch effect.
‘‘It is the first model to reproduce all
known traffic states,’’ says team member Robert Barlovic.
The team’s trick is to be realistic
about driver behaviour.
‘‘Real drivers tend to hinder each
other when doing things like changing
lanes. All this has to be taken into
account,’’ says Dr Schreckenberg.
And where previous models have
simplified the way cars move — by
assuming they can stop immediately
without slowing down first, for
example — the new model is more
sophisticated.
Dr Schreckenberg’s model divides
the road into a grid, with one line of
cells representing each lane on a highway. Cells in the grid are marked as
either containing a vehicle or empty.
The number of empty cells between
the virtual vehicles depends on the
way the drivers are behaving.
» The ‘pinch effect’
■ Occurs when a car suddenly
changes lane, forcing the driver
behind to brake hard and the traffic
behind to bunch up.
■ Now used in a sophisticated
German computer program which
can accurately predict traffic jams.
Newfound accuracy has been achieved
by modelling two behaviours, Dr
Schreckenberg says.
These are dubbed ‘‘aggressive’’
behaviour — in which drivers either
get too close to the car in front and
have to brake, or in which they change
lanes too quickly, forcing others to
brake — and ‘‘defensive’’, in which
they drive at a generally safe distance.
The model moves vehicles according to rules that embody realistic rates
of acceleration and deceleration.
The result is a software model that
combines realistic driver behaviour
with realistic physics.
The model is already being used to
forecast traffic on the autobahn network around Cologne. Its forecasts,
which predict conditions up to an hour
ahead, are displayed on the web at
www.autobahn.nrw.de.
More than 90 per cent of the time it
correctly predicts traffic density. But
the website has already become a victim of its own success.
Some of the 300,000 people a day
visiting the site are replanning their
journeys on the basis of its forecasts,
and this is beginning to make the forecasts themselves less accurate.
And soon it could get even worse
when the website becomes available on
3G cellphones, Dr Schreckenberg says.
So the researchers are now trying
to adjust the way the traffic information is provided to drivers to take this
destructive effect into account.
One idea might be to provide less
complete traffic information to encourage drivers to adopt more varied
strategies for evading congestion.
— NEW SCIENTIST
Corrections & Clarifications
■ e.g. yesterday had many incorrect G-codes. G-codes are supplied to the Herald.
■ Clarification: A recommendation that parents use drawers, a suitcase or box as
a baby’s bed was made by Plunket, not Kaitaia coroner Robin Fountain as
reported yesterday. Mr Fountain endorsed recommendations given in evidence by Plunket Clinical Adviser Trish Jackson-Potter at an inquest into a
baby’s death.
■ Cyclone Bola occurred in 1988, not 1986, as stated yesterday.
■ Clarification: A story on dining in Viva on Wednesday was accompanied by a
photograph of Joe Beattie of Auckland. Mr Beattie, a performance coach, was
not connected with the report.
To have errors corrected: fax (09) 373-6421; ph (09) 373-6400, ext 8224; email
[email protected]
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