A computer has been used to decipher the enigmatic smile of Leonardo da Vinci's Mona Lisa, concluding that she was mainly happy.
The painting was analysed by a University of Amsterdam computer using "emotion recognition" software.
It concluded that the subject was 83% happy, 9% disgusted, 6% fearful and 2% angry, New Scientist magazine was told.
The computer rated features such as the curvature of the lips and crinkles around the eyes.