Northwestern University Computational Photography Lab

New app reveals the hidden landscapes within Georgia O’Keeffe’s paintings

WASHINGTON, D.C.—Ever wonder whether a lost masterpiece lies hidden under the surface of a newer work? Researchers at Northwestern University have developed a simple-to-use app, unveiled here today at the annual meeting of AAAS (which publishes Science) that can zoom in on the smallest details of a painting and depict them in 3D, transforming brushstrokes into canyons and cliffs. The resulting landscapes, which can easily be mistaken for satellite images of Earth’s rugged terrain, could help art conservationists and historians preserve pieces at risk—and reveal what may lie beneath.

Consider, for example, the small goosebumplike blebs that pepper the paintings of Georgia O’Keeffe, the mid–20th century artist made famous by her depictions of flowers and the southwestern United States. At first, art conservationists thought these tiny protrusions, imaged above from her painting Pedernal 1941, were grains of sand embedded in the paint. But they soon recognized them to be the result of chemical reactions between some components of the paint itself. The researchers say the blobs—which can grow and, over time, cause the overlying paint to flake off—result from reactions between lead and zinc ions and the fatty acids that are used as binders in the paint.

Monitoring the growth of these blebs in artwork of any sort can help conservationists figure out the best way to diagnose problems, prevent or slow damage, and possibly restore the artwork. The 3D images generated by the app could have other uses, too, the researchers suggest. Subtle differences in the thicknesses of paint on a canvas, for example, might betray the existence of older paintings—possibly even lost or unknown masterpieces—beneath the more-recent surface layers. Art conservators at a handful of museums are already using a beta version of the team’s app; a finalized version will be released to the public later this year.