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.