Van Gogh’s brushstrokes: marks of authenticity?

The process of attributing paintings relies partly upon recognition of an artist’s hand. Around the middle of the last century, Maurits M. van Dantzig (1903–1960) attempted to define the ‘characteristic touch’ of the painter, Vincent van Gogh (1853–1890). His broader aim was to develop a flexible yet precise method to measure the features of both spontaneity and inhibition, evident in the style of brushwork for example. The underlying idea that these qualities can be used to separate a genuine work from a second-rate copy or forgery still plays a key role in attribution studies today. A recent initiative explores the potential of advanced computer image analysis techniques to help identify and quantify these properties at the scale of brushwork. This paper describes the basic principles of the method used, involving statistical analysis of different size wavelets present in digital images of paintings by Van Gogh or other artists.