Computers tackle fresco puzzles


Some are using the invaluable experience of the trained eye, while others are working with pixels and algorithms. The goal, however, is common and sacred: the restoration of the frescoes at Akrotiri on the Cycladic island of Santorini has brought together Greek archaeologists and computer scientists from Princeton University, in a scientific program under the name «Grifos» (Riddle). The collaboration between Akrotiri archaeologists and restorers and Princeton University, as well as University College London, goes beyond the realm of digital assistance. A recent gathering at the island's excavation site united students, young archaeology researchers and computer scientists from five different countries and seven universities (Athens, Thessaly, Ioannina, Liverpool, London, New York and Princeton). For the last two years, a three-dimensional puzzle showcasing fragments of colorful frescoes has been studied on the screens of computer scientists, archaeologists and fresco restorers, both at the excavation site on Thera as well as at Princeton University in the United States. A group of Princeton computer scientists working along with archaeologists and - above all - restorers at Akrotiri, developed a special software titled «Grifos,» whose mission is to decode the secrets of frescoes. The software's logic is straight-forward: The system is searching for connections between hundreds of fresco fragments. «It is a faster and cheaper procedure than traditional methods of restoration,» notes Professor Christos Doumas, director of the Akrotiri excavations. «Under no circumstances are computers able - at present - to replace the trained eyes, brains and hands of our restoration experts but, as far as we're concerned, it is extremely interesting to observe ancient Thera's frescoes opening new roads in the development of technology that focuses on executing complex archaeological objectives, such as the restoration of hundreds of square meters of Akrotiri's frescoes,» said Doumas. Among those who attended the recent meeting were Thomas Funkhouser and Szymon Rusinkiewicz of Princeton University's Computer Science Department, Tim Weyrich, a computer science lecturer at University College London, and Doumas, of the University of Athens, all of whom informed participants of the latest conclusions reached regarding the archaeological findings, the methods used in the restoration work of the last four decades as well as the operating principles of the Grifos software program. It is worth noting that each year, under the direction of Dimitris Gontikas, Princeton University's program of Hellenic Studies is involved in a wide range of activities regarding issues of Greek culture.