Every once in a while, well-intentioned attempts to save a valuable painting or artifact from the decay of time bombs pretty badly. Consider the thousand-year-old ancient parchments that were laminated in the late 1950s or early 1960s–during that era’s love affair with plastics–in order to protect the valuable documents from the wear and tear of a long life. Four decades later, the yellowed and brittle laminate had to be painstakingly removed from Belgium’s oldest parchment, the Codex Eyckensis, as the decaying plastic began to exacerbate the injuries it had aimed to avoid.
Such hard lessons have since pushed conservators to look for easily reversible, minimally invasive ways to protect or restore cultural masterpieces—sometimes opting to shun any interventions altogether. Another possibility is to consider a digital restoration technique that offers “all the benefits of an Undo button,” says Daniel Aliaga, a computer scientist at Purdue University.
Aliaga and his Phd student Alvin Law have designed software that can project light images on to sculptures or paintings that, for example, can reveal to the viewer what the decaying masterpiece may have looked like before decades or millennia of deterioration. The projection can also boost faded colours on a painting or touch up decorative tints on a piece of pottery or a sculpture’s exterior. Turn off the projector, and the piece reappears in its current day form.
Previous attempts to digitally visualize possible restorations to art simply projected images onto a wall or screen. Aliaga’s digital restoration technique projects images directly on to the art which is tricky to do in 3D, he says. But working with Richard McCoy at the Indianapolis Museum of Art, Aliaga has tried out the technique with ancient pottery from Mexico’s pre-Columbian Casas Grandes style and Neolithic people in China. He’s also given 16th century angel sculptures a digital facelift.
Besides visions of what the artwork may have initially looked like, the digital technique could also project more whimsical or educational images. One possibility is to project an X-ray scan of a sculpture that highlights interesting scaffolding or materials beneath the artwork’s surface. Another option is to project the results of so-called infrared reflectography measurements, a non-invasive technique which can reveal features that an artist initially sketched on a canvas but then decided not to include in the final painting. These initial sketches could be projected on to the artwork to show how the painting was initially envisioned. Finally, you could also imagine using the technique to do a little artistic alchemy, such as turning a marble statue into wood using light.
Although light projection seems, well, light to the touch, could this digital projection cause damage that would leave future generations shaking their heads? Harsh light can indeed injure masterpieces, but Aliaga says his technique doesn’t project light any more intense that the artwork would normally receive while on display at a museum—which is typically strictly controlled by curators or artwork owners.