By James Ovie
An artificial intelligence neural network discovered something unusual in a famous painting by Raphael: one of the faces was not painted by Raphael himself.
The painting is called Madonna della Rosa, and scholars have long debated whether it is an original by Raphael. While determining the provenance of a piece of art requires a combination of evidence, a new analysis method based on artificial intelligence algorithms supports the idea that at least part of the painting is by another artist.
Researchers from the United Kingdom and the United States trained a customised AI algorithm specifically on the brushstrokes, colours, shadows and other details of Raphael’s known works.
Mathematician and computer scientist Dr Hassan Ugail explains: “We used deep feature analysis technology to let the computer learn to recognise the subtle style of Raphael’s work, from brushstrokes to tones, from shading to overall layout.”
Machine learning often requires large amounts of data to train, which is a challenge for an artist like Raphael who has a limited body of work in his lifetime. In this case, the research team modified ResNet50, a pre-trained architecture developed by Microsoft, and combined it with a traditional machine learning technique called support vector machines.
This method has previously been shown to be 98% accurate in identifying Raphael paintings, and this time they not only asked the AI to analyse the entire painting but also studied individual faces within it individually. The results showed that the faces of the Virgin, the Holy Child and Saint John were all painted by Raphael himself, except that the facial style of Saint Joseph in the upper left corner was obviously different from the other parts.
Researchers note that in previous debates over the painting’s authenticity, St. Joseph’s face was considered less refined than the other figures in the frame.
“The analysis of the entire painting is inconclusive,” Dr Uguerre said frankly, “but when we analysed each face individually, we found that except for Saint Joseph, the other parts were highly consistent with the style of Raphael’s work.”
Researchers speculate that the face of St. Joseph may have been painted by one of Raphael’s students, Giulio Romano. Although this speculation still requires further research, there is no doubt that AI technology has revealed the secret Classic paintings offer new tools.
According to IT Home, the “Madonna of the Rose” was created between 1518 and 1520. As early as the mid-19th century, some art critics questioned that the painting was not entirely by Raphael.
It is worth mentioning that the research team emphasised that AI is not meant to replace art experts but to become their right-hand assistant. Dr Ugel said: “Art identification is a complex process that requires consideration of various factors, such as source, pigment, preservation status, etc. AI is just one of the auxiliary tools, and the final judgment is still made by experts.”
The findings have been published in the journal Heritage Science.