1. A system for automatically detecting neutral, expressionless face images in digital images, the system comprising: an image acquisition unit; an face detector receiving input from the image acquisition unit, detecting one or more face subimages of one or more faces in the image; a characteristic point detector that receives input from the face detector and that estimates one or more characteristic facial features as characteristic points in each detected face subimage, one of the characteristic points being a first and a second mouth corner on a mouth of the face; a facial feature detector that detects one or more contours of one or more facial components; a facial feature analyzer that determines a mouth shape of the mouth from the contour of the mouth and creates a representation of the mouth shape, the mouth being one of the facial components; and a face classification unit that classifies the representation into one of a neutral class and a non-neutral class.