Using deep feature analysis, we used pictures of authenticated Raphael paintings to train the computer to recognize his style to a very detailed degree, from the brushstrokes, the color palette, the shading and every aspect of the work,” says mathematician and computer scientist Hassan Ugail from the University of Bradford in the UK.
https://www.sciencealert.com/ai-detects-unusual-signal-hidden-in-a-famous-raphael-masterpiece
That’s a pretty broad stroke
Waiting For Charlemagne 