Computer engineers look at Mona Lisa

CHAMPAIGN, Ill. -- Mona Lisa probably wasn't a man, and it's even more unlikely that the artist who painted the famous painting used himself as the model.

So conclude University of Illinois researchers, who created a buzz last year when their facial-recognition software was used to analyze the Mona Lisa's enigmatic smile. (Conclusion: The model was happy, with touches of disgust, fear and anger, at least as Leonardo da Vinci painted her.)

Meanwhile, in the latest twist, UI Professor Thomas Huang has analyzed the painting to determine its subject's likely gender and compared it with a self-portrait of da Vinci.

The analysis, using the facial-recognition software developed by Huang and his students, says there's a 60-40 probability the painting is of a female. Even if it is a man, it doesn't match up well with Leonardo's sketch of himself.

"Of course, nothing proves anything," Huang, a UI electrical and computer engineering professor, said recently. "At least it indicates these conjectures may not be right."

The "conjectures" include the notion that da Vinci used himself or another man as the model for the painting.

16th century portrait

The portrait, which da Vinci probably completed in 1507, is often said to be of Lisa Gherardini, wife of Francesco del Giocondo, a wealthy silk merchant from Florence, Leonardo's hometown. The painting's whole title is "Mona Lisa del Gioconda."

But various alternatives have been suggested with more or less justification through the years, including Leonardo himself, his mother, the Duchess of Milan Isabella of Aragon and a female friend of the powerful Florentine Giuliano de Medici.

A Bell Labs researcher used early photo morphing software to compare Mona Lisa with what's believed to be a da Vinci self-portrait and concluded that the artist was the model.

Huang, who co-leads the Human-Computer Intelligent Interaction group at the UI's Beckman Institute, is working on facial recognition for a variety of purposes.

Those include security systems and making your computer more personal by getting it to recognize you and set itself up accordingly, and even adjust to the moods reflected on your face.

Huang said the technology also might be used in "smart kiosks" electronic bank tellers that could recognize and address a user properly.

In December, Nicu Sebe, a professor and sometimes collaborator of Huang's at the University of Amsterdam in the Netherlands, drew international attention by using software from the UI to examine the emotional state of the Mona Lisa.

Huang said the fun, as well as useful, test of the system has led to a small wave of requests to look at more paintings, showing that the technology may be useful to art historians and others in the humanities in addition to its other potential uses.

They've examined a self-portrait of the suicidal Vincent van Gogh, whom the software tagged as exhibiting profound sadness. They've also looked at Edvard Munch's "The Scream" for a Japanese TV station. The software pegged the dominant emotion in that painting's expressionist subject as surprise, not fear.