Math to the rescue

Every few years, we're wowed by news of some jaw-dropping sum paid for a previously unknown painting or drawing by a famous artist. But how can a buyer truly be sure that a piece is a legitimate creation of, say, Leonardo or Gauguin? Mathematicians at Dartmouth College, in Hanover, N.H., may have the answer. They recently presented a computer-based statistical analysis technique which they say will help art historians and conservators discover even the most skilled forgery.

Their method, called sparse coding, learns what characterizes the artist's style at a level of detail that is practically imperceptible to the eye of even the most experienced appraiser. It works by examining small patches of a picture and breaking them down to a set of essential elements.

"The aim is to establish for each artist a vocabulary of brush strokes or pencil marks that defines his or her style," says James M. Hughes, a doctoral candidate at Dartmouth who coauthored the research reported in Proceedings of the National Academy of Sciences.

Read the report in IEEE Spectrum here.