Detail of Adam’s brown skirt under magnification (7.5x). In the early modern period, Adam’s naked torso was covered with this skirt, painted with one or more organic colourants.

The ‘virtual restoration’ process was based on a digital colour photograph and an infrared image of the overpainted details. The infrared image (above, left) revealed the original appearance of the area beneath the later additions. The part to be ‘restored’ was marked and used as a boundary to solve a partial differential equation that is guided by the local structure encoded in the infrared image and extracted in a false-colour image (above, right). This process, called osmosis filtering, resulted in the ‘restored’ image on the bottom left. Non-local image features, such as textures and patterns, were restored in a second step using a ‘copy & paste’ technique, which resulted in the image on the bottom right. The reconstructed details were then integrated into the scene, as shown in the ‘Virtual restoration’ layer.

Detail of one of the misspelled captions under magnification (7.5x). It mistakenly reads ADEM ET VEE rather than ADAM ET EVE.

The grass below the feet of God the Father was painted with a complex mixture containing indigo and azurite, both identified by reflectance spectroscopy thanks to the typical absorptions at 660, 1491, 2283 and 2350 nm (above). XRF analysis reveals the additional presence of lead-tin yellow (Pb and Sn in the spectrum below).