Artificial intelligence (AI) can be trained to see details in images that are invisible to the human eye. An AI neural network has identified something unusual about the face in a Raphael painting. It was not actually painted by Raphael.
The face in question is that of St. Joseph, and can be seen in the upper left of the painting known as the Madonna della Rosa (or Madonna of the Roses).
In fact, scholars have long debated whether this painting is an original by Raphael. Although a variety of evidence is needed to conclude an artwork’s provenance, a new analysis method based on AI algorithms is gaining support among people who believe that at least some of the strokes are the work of another artist.
British and American researchers have developed a custom analysis algorithm based on works known to be the result of the Italian master’s brushstrokes.
One of these faces is different from the others. (Prado Museum)
“Using detailed feature analysis, we use photographs of authenticated Raphael paintings to recognize his style to an extremely detailed level, from brushstrokes to color palettes to shading to every aspect of the work. We trained the computer to do it,” said Hassan, a mathematician and computer scientist. Ugair, from the University of Bradford in the UK, explained the researchers’ findings in December.
“Computers can see much deeper than the human eye, down to the microscopic level.”
Machine learning processes typically need to be trained on vast samples, but when it comes to an artist’s life’s work, that’s not always available. In this case, the team modified a pre-trained architecture developed by Microsoft called ResNet50 in combination with a traditional machine learning technique called support vector machines.
This method has previously been shown to have an accuracy level of 98% when it comes to identifying Raphael’s paintings. Usually trained on whole pictures, here the team also asked them to look at individual faces.
The Virgin, the Child, and St. John all appear to have been created by Raphael, but this is not the case with St. Joseph. Researchers note that previous debate over the painting’s authenticity has considered St. Joseph’s face to be less well rendered than the other faces in the frame.
Perhaps someone else touched St. Joseph’s face. (Ugail et al., Heritage Science, 2023)
“We tested the entire Dela Rosa and the results were inconclusive,” Ugail said.
“So we tested the individual parts and found that while the rest of the photo was confirmed to be Raphael, Joseph’s face was most likely not Raphael.”
It is possible that Giulio Romano, one of Raphael’s students, was responsible for the fourth face, but this is by no means certain. This is another example of how modern technology reveals the secrets of classical painting. This time we’re using AI.
Experts believe that the Virgin was painted on canvas between 1518 and 1520. It was in the mid-1800s that art critics began to suspect that Raphael did not paint all of his works.
Although these suspicions have now almost certainly been proven correct, the research team behind this study believes that this AI will help art professionals in the future, rather than replacing them. I would like to emphasize that this is the case.
“This is not a story about AI taking away people’s jobs,” Ugair said. “The process of authenticating a work of art requires examining various aspects such as the provenance, pigments, and condition of the work.
“However, this type of software can be used as one tool to aid the process.”
The study was published in the journal Heritage Science.
A previous version of this article was published in December 2023.
