Using AI to preserve cultural heritages

Artificial intelligence is now being increasingly used to protect and preserve the country's ancient cultural heritages, which are human treasures but face risks brought by time and nature, Wu Jian, director of the Cultural Heritage Digitization Institute at the Dunhuang Academy, has said.

Speaking at the 2019 World Artificial Intelligence Conference's Shanghai West Bund Forum, Wu noted that the historic Mogao Grottoes in Dunhuang, northwest China's Gansu Province, are described as a Buddhism art "trinity" of structure, mural and sculpture.

The themes of the elegant murals there include traditional stories and myth, and the well-known dances of feitian, or flying goddess.

However, these murals, dating back more than 1,600 years, could never last forever in their original state. They are fragile in front of nature's power like sandstorm, heavy rains and floods, as well as human activities — their bright colors having faded and the patterns blurred, some even disappeared.

"Despite the murals being displayed to the public, some other things also did damage to the grottoes, such mildew and smoke while they were defiled by visitors using knives to scratch their surface in the past," said Wu. "Such destruction caused us deep pain, spurring people's sense of a mission to protect and preserve them."

Between the 1990s and 2006, the Dunhuang Academy undertook the process of digitalizing the murals, raising the precision level, in technical terms, from 75D-PRE to 300D-PRE. Under special circumstances, it could reach 600D-PRE.

Starting in 2006, it launched digitalization work on the grottoes, including three-dimensional reconstruction projects on sculptures and ruins, and introduced AI technology into their protection work for the first time.

From 2014, the academy enhanced the application of its digital cultural relic resources and designed many exhibitions with high-tech means.

Besides two-dimensional digital information collection and 3D reconstruction, it is also working on digital panorama display and virtual reality and augmented reality programs of the grottoes.

Such digitalization support has also been provided to cultural relics in other regions, including Shanxi and Shandong provinces as well as Tibet, Xinjiang Uygur and Inner Mongolia autonomous regions.

AI is also applied for the restoration of damaged murals. For instance, the canthi of a character on a mural from the Tang Dynasty was damaged and its art technique not available anymore. The academy then used AI to recognize the damage and used computer technology to display how to repair it.

To attract more people to learn about Dunhuang, three years ago the academy developed and released online virtual reality programs that display 30 grottoes. They serve as an international database and platforms for interaction and sharing of Dunhuang resources.