Mind’s eye view

A UK university is developing 3D X-ray scanning techniques based on the way the human brain processes visual images.

Royal Holloway, University of London, believes the technology, called HolViz, could greatly increase the efficiency of airport security scanners by allowing operators to view, zoom in on and manipulate 3D images of items in luggage or freight.

HolViz, developed by Royal Holloway neuroscience professor Johannes Zanker, aims to enable computers to generate the images by developing a processing system based on neuromorphic engineering techniques – design principles based on the construction of biological nervous systems.

Zanker said the HolViz project would seek to apply to a machine vision system themechanisms used by humans to construct a 3D view of the world.

Central to this will be the application of motion parallax, the complex phenomena that allows us to perceive depth by causing images of nearby objects to move more rapidly on the retina that those further away when movement occurs.

In the case of an airport system, the necessary motion would be provided by a conveyor belt carrying luggage or other cargo.

The way the human brain processes stereoscopic visual data from two eyes will also play a part.

Zanker said the neurological mechanisms behind human vision were fairly well understood. ‘This is essentially a machine vision problem,’ he said. ‘The idea is to use multiple X-rays to reconstruct images in a virtual environment within the system, not in the mind of the scanner operator.’

If this could be achieved, said Zanker, scanner operators would be able to isolatesuspicious objects within a packed suitcase, rotate them for viewing from different angles or go further inside for a closer look in a similar fashion to engineers using CAD tools.

HolViz has received £75,000 from national technology funding body Nesta and Park, a business support network run jointly by Royal Holloway and Brunel University.

As well as airport security, Royal Holloway believes HolViz could have applications ingeneral freight scanning, mail handling and other areas where rapid, low-cost inspection is needed.

After proving the feasibility of the process, Zanker plans to move on to prototyping and have a device incorporating the system ready for production by 2006.

HolViz is the latest in a string of attempts to apply new technologies to the scanning sector in the wake of September 11, when airport security suddenly shot up the agenda.

These include the use of millimetre wave sensors as an alternative to X-rays, systems that can detect the ferro-magnetic material found in weapons, and devices able to identify neutrons emitted by the fissile nuclear material needed to make so-called ‘dirty bombs.’