Computer art breakthrough in hunt for the missing

Artist’s impressions of how people age are inaccurate – and new algorithm can do it far better, say experts

ARTISTS’ impressions of how missing people such as Madeleine Mccann and Ben Needham might look years after they vanished may be completely unreliable, a new study suggests.

Researchers at the University of Bradford have developed a method of ageing facial images which they say could enhance the search for people across the world.

The technique involved taking careful measurements from photographs of 500 people when they were aged 21 months, six, 14 and 22.

They then used the results to create an algorithm that accurately predicts how a face changes over time.

When they tested the procedure on a photograph of missing youngster Ben Needham, they found the resulting image bore little resemblance to artists’ impressions of his older self.

Ben disappeared on the Greek island of Kos on July 24 1991, when he was only 21 months old. He has never been found, but several images have been produced by investigators over the years, showing how he might look at ages 11-14 years, 17-20 years, and 20-22 years.

However the researchers say their images more closely resemble what Ben might look like today, and could prove helpful to the search.

Prof Hassan Ugail, of Bradford’s Centre for Visual Computing, said: “No criticism is implied of existing age-progression work. Instead we are presenting our work as an … improvement that could make a contribution to this important area of police work.

“Our method generates more individualised results and hence is more accurate for a given face. This is because we have used large data sets of faces from different ethnicities as well as gender to train our algorithm.

“Furthermore, our model can take data from an individual’s relatives, if available, such as parents, grandparents and siblings.

“This enables us to generate more accurate and individualised ageing results.”

The problems of using artists’ impressions were highlighted in 2015 when a man answered a Greek television appeal claiming to be Ben Needham because he resembled the image released by investigators.

However police soon realised he had already been Dna-tested several years before. Nearly 30 people contacted South Yorkshire police after the image was publicised, but none led to any concrete information.

The new approach looks at key features, such as the shape of the cheeks, mouth and forehead, at a certain age, mapping how they change over time. The information is fed to a computer algorithm which then synthesises new facets to produce photographic-quality images of the face at different ages.

“Each year around 300,000 missing person cases are recorded in the UK alone,” Prof Ugail added.

“This has been part of our motivation in endeavouring to improve current techniques of searching for missing people, particularly those who have been missing for some considerable time.”

The findings will be presented at the International Conference on Missing Children and Adults in Dundee later this month have been published in the Journal of Forensic Sciences.