KRAKOW, Poland -- No secret codes have come to light in a new digital examination of Leonardo da Vinci's "Lady With an Ermine," but the scan has revealed bolder hues, softer contours and other details lost in centuries of deterioration and touch-ups on the masterpiece.
After claiming to have used his technique to uncover secrets about "Mona Lisa," French inventor and engineer Pascal Cotte has now used the special "multi-spectral" camera that he developed to penetrate beneath layers of restoration on the Leonardo portrait of an Italian duke's young lover.
He says his 240-megapixel scans of the painting gives art lovers a very close approximation of what it must have looked like when Leonardo finished painting it around 1490.
"I was afraid to discover a lot of restoration and retouching," said Cotte, who used his scientific training in light and optics to develop his camera and who has scanned works by van Gogh, Brueghel, Courbet and other European masters.
"There is some, of course. She is ancient -- it's been 500 years. But I was very surprised to discover a very good painting with few restorations except for the background -- and a 100% Leonardo da Vinci painting."
Cotte's camera uses sensors to detect light from both the visible spectrum and the infrared and ultraviolet ranges invisible to the human eye, enabling him to burrow through layers of paint to "see" into the painting's past.
The brighter colors and gentler contours of the female figure uncovered in the "virtual cleaning" could inspire a new appreciation for a work that was off limits to Western viewers for decades during the Cold War, housed behind the Iron Curtain in a museum in Krakow, Poland.
The Renaissance oil painting, one of four female portraits by Leonardo, shows a graceful young woman in three-quarter profile wearing a sumptuous low-cut red and blue dress as she holds a white ermine. Historians believe the subject was Cecilia Gallerani, the mistress of the Duke of Milan, Ludovico Sforza, when she was 16 or 17.
Kept behind glass in a dimly lit room in Krakow's Czartoryski Museum, the painting is considered a masterpiece because of Leonardo's skill in realistically depicting Cecilia and the ferret-like animal she holds as well as the dynamism of her body as she turns toward a light that bathes her.
Among the hidden layers that emerged from the "virtual cleaning" is an original blue-gray background that was painted over in a deep black -- probably in the 19th century. The addition of black created a harsh contrast with the figure, thus eroding a sense of three-dimensional perspective.
It "grossly disfigures the painting," said Jacques Franck, an art historian who cooperated with Cotte on the project and who is a Da Vinci expert with the Armond Hammer Center for Leonardo Studies at UCLA.
"That part of the face just against the background presents a harshness completely strange to Leonardo," he said. "The soft transition has been eaten up in the contour of the flesh against the dark background."
The spectral photographs also revealed other details, putting into view more of a transparent veil that covers Cecilia's braided hair. And the digital scan revealed a much whiter ermine, as well as a more vibrantly colored red-and blue-gown.
Franck argues that the new study, carried out in September, should dispel any lingering doubts that the work is fully by Leonardo's hand, rather than by his studio, as some historians have believed.
"These soft transitions missing are absolutely essential in Leonardo expertise to decide whether it's by him or not, because Leonardo's understanding of form in space is so specific that he wouldn't use any harsh contours," Franck said.
Cotte had previously used his camera on "Mona Lisa," saying he revealed that Leonardo had originally given her eyebrows and lashes, that her face was originally wider and the smile more expressive than they were ultimately painted, and that she holds a blanket that has all but faded from view today.
Some art experts not involved in the study have expressed concern that the method could inspire ultimately ruinous attempts to restore old masterpieces such as "Mona Lisa."
Michael Daley, director of ArtWatch UK, an organization devoted to protecting artworks from overly aggressive restoration, said that though the camera is an "amazing apparatus," it is "dangerous and naive" to claim the system can uncover the "true colors" of pictures.
"In old paintings, the 'original' condition no longer exists -- pigments, paint mediums all undergo varying changes and degradations with age and circumstances," Daley said. "The camera is dangerous because restorers -- who always want to work on the most famous paintings -- will be emboldened in their ambitions and enabled politically to do so."
Alessandro Vezzosi, a Da Vinci expert and the director of a museum dedicated to the artist in his hometown of Vinci, said, however, that he finds Cotte's apparatus especially interesting because it will allow just the opposite -- the chance to recover the original colors without ever touching the paintings.
"This is one of the many opportunities we have today to gain a deeper understanding" of such works, Vezzosi said.