Uncoding da Vinci’s ladies digitally


After unlocking the secrets of the Mona Lisa, a French scientist has turned his all-seeing “multi-spectral” camera on a lesser-known Leonardo da Vinci muse in Poland, the ‘Lady with an Ermine’.

Engineer and inventor Pascal Cotte virtually strips away centuries of sometimes sloppy restoration work to provide a digital image of a painting as it may have left the artist’s studio — an abiding question among art historians and art lovers about such masterpieces.

Cotte was called in by the Czartoryski Museum in Krakow in southern Poland, which is home to a collection built up over the centuries by the eponymous Polish princely family. His unique 240-megapixel camera uncovers the true colours of a painting, literally.

Cotte found that the late 15th century wood-panel portrait was not painted on the black background visible today. “The background was deep blue, very lightly shaded with earth, and probably an azurite mixed with earth,” added Cotte.

The ‘Lady with an Ermine’, bought by the Czartoryski family in Italy in 1798, was among the works looted by the invading Germans in 1939. It was hung in the office of the Nazi governor Hans Frank, who then decamped with the portrait when the Germans fled in January 1945. The painting was discovered by US troops at Frank’s villa in Bavaria and later returned to Poland.

Though a major piece in the Czartoryski collection, nagging doubts persisted over how much of ‘Lady with an Ermine’ was da Vinci’s own hand and how much was that of his assistants’.

Cotte’s conclusion, based on a virtual version he built as close as possible to the original, suggests it is nearly 100 per cent da Vinci’s handiwork. Cotte’s camera gives insight into colours, pigments and brush-strokes underneath a weathered surface.

“It enables us to break down the light spectrum three levels into the pictorial layer, from the ultraviolet to the infrared, and from the visible to the invisible,” he explained. In the ‘Lady with an Ermine’, he discovered hidden traces under the ermine’s left paw and muzzle.