"Art historians have long used scientific tools to help them decide whether drawings and paintings are real or fakes, like counting isotopes in lead-based paints to spot anachronisms or shining X-ray and infrared radiation on oil portraits to discover what lies beneath.
Now researchers at Dartmouth College have introduced a forensic tool appropriate to the digital age: they have fed digitally scanned artworks into a computer, and then used image-processing techniques to create statistics describing the pen and brush strokes.
Like a connoisseur - a blend of Bernard Berenson and HAL - the computer analysis detected subtle differences in these strokes that might help distinguish an artist from an imitator."
-Who Really Wielded the Paintbrush?
By ANNE EISENBERG
NY Times, December 23, 2004
If you are interested in image processing, take a look at ImageJ:
powerful software developed at the NIH and available as a free download far any platform (Jave, Unix, Mac and PC). This software is as powerful as Adobe Photoshop (with many similar features) in addition it has may features that make it a perfect forensic tool to aid art historians in the analysis of images.
The most famous example of digital imaging software supporting art historical suppositions is the superimpostion fo Leanardo’s Self-Portrait over the face of the Mona Lisa. The Aha! Moment this caused has spurred many other speculations about the master from Vinci, leading invariably to The Da Vinci Code.