UK team digs into data from scroll scans

jwarren@herald-leader.comAugust 23, 2009 


  • Watch the video to learn more about how the UK imaging process works.

University of Kentucky computer experts are entering the crucial stage of their quest to unlock the secrets of two Roman scrolls buried in a volcanic eruption almost 2,000 years ago.

The UK team, led by computer scientist Brent Seales, spent July in Paris, France, arduously making CT scans of the scrolls, which survived the famous 79 A.D. eruption of Italy's Mount Vesuvius. The delicate papyrus scrolls haven't been read or even unrolled since the eruption.

Seales' group recently returned to Lexington, bringing back two terabytes of stored computer data generated from the scans. Next, they must subject all that data to sophisticated computer processing at UK's Center for Visualization and Virtual Environments, aimed at producing 3-D images of the scrolls. The researchers hope that ultimately will allow them to digitally "unroll" the scrolls, and see what's written on them.

"We're starting the serious work now," Seales said. "In a few weeks, we should know whether we'll be able to tease out some of the writing. Seeing the text is going to be the trick, but we have some tricks of our own that we think will help."

UK is known for this kind of computer work under its Enhanced Digital Unwrapping for Conservation and Exploration project, called EDUCE. Probing the Roman scrolls is the project's most ambitious undertaking yet.

Classical scholars think the scrolls probably contain works in Greek by Philodemus, a Roman writer and philosopher born about 110 B.C. But that's only a guess, because no one has seen inside the scrolls since Aug. 24, 79 A.D.

On that date, Vesuvius buried the Roman cities of Pompeii and Herculaneum under cubic yards of super-heated ash and debris, killing all who couldn't flee. The towns essentially were forgotten until excavators stumbled upon them in the 1700s.

At Herculaneum, searchers uncovered a luxurious villa containing almost 2,000 papyrus scrolls, which the intense volcanic heat had preserved as fragile hunks of carbon.

Scholars immediately tried to open them, with generally disastrous results. Some scrolls simply crumbled. In other cases, workers managed to peel off scroll pieces and flatten them, but the jumbled pieces were unreadable.

Ultimately, most of the scrolls were stored, unopened, in Italian and French museums. The two scrolls that the UK team scanned last month are at the French National Academy in Paris.

Dating almost to the time of Christ, the carbonized scrolls are so delicate that simply touching them causes surfaces to flake off and turn to powder. Conservators from the French academy did all the handling.

Each scroll was placed in a custom-made holder to support it in an upright position. Then, multiple X-ray snapshots of each scroll were taken, using a scanning system developed at UK based on medical CT scanners but operating at much higher resolutions.

Lead shielding, placed around the equipment, protected team members. Altogether, the apparatus weighed about 600 pounds.

Each snapshot produced a 2-D X-ray picture looking all the way through the scroll. After each picture, the upright scroll was rotated a fraction of a degree, and another picture was taken. The process continued until a series of pictures representing a 360-degree view of the scroll was completed.

Because numerous individual snapshots were required, a scan could take up to 30 hours. Also, each scroll was scanned repeatedly at different angles, settings and resolution levels in hopes of capturing the clearest possible images.

Matt Field and Ryan Baumann, two UK team members who worked on the long and tedious scans, said they never expected to be taking computerized pictures of ancient manuscripts when they went into computer science.

"But it really is exciting to combine classical scholarship with what computers can do," Field said.

The two terabytes of data the team collected are "immense," according to Seales. One terabyte is 1,000 gigabytes, or roughly enough space to store 250,000 songs or about 1 million regular photographs.

But the heavy lifting, Seales says, will be in making sense of all that raw data.

According to UK, the 2-D X-ray images gathered in France will be run through special computer software that aligns and reconstructs them into 3-D images.

Seales and his team then hope they will be able to digitally separate the many rolled up scroll layers and open them in virtual reality to produce flat pages that can be read.

The outcome might hinge on the ink used in the scrolls. If the ink was carbon-based, Seales says, it might not be possible to visually separate the carbon ink from the carbonized papyrus. In other words, the scrolls could be unreadable. But if the original writer used a metal-based ink, a readable computer image could be obtained more easily.

"Obviously, I'm hoping for a positive result," Seales said. "But with so much data, there will be a fair amount of waiting just to let the computer crank through it."

Seales thinks it ultimately will be possible to read the scrolls, even if new computer equipment has to be invented to do it.

"Things are on the horizon that could be applied to this. We may just have to let them develop," he said.

Even so, UK researchers already have learned some new things about the scrolls.

Early scans detected grains of sand inside the scrolls — probably from sand ancient writers used to blot their ink. Also, the scrolls are not rolled up in neat spirals. Instead, there are many interior folds, breaks and voids — probably caused by the volcanic heat when they were buried by Vesuvius.

"I was kind of hoping that we'd find something weird wrapped up in one of the them, a key or something like that," Seales says. "Of course, that didn't happen.

"But it's a miracle that these things even survived. It's really pretty awe-inspiring."

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