1. A method of segmenting a composite image of pixels into a number of fields corresponding to lay-out elements of the image, the pixels having a value representing the intensity and/or color of a picture element, the method comprising: constructing separating elements corresponding to rectangular areas of adjacent pixels of the image having a background property indicative of a background of the image; and constructing a graph representing the lay-out elements of the image by defining vertices of the graph on the basis of intersections of separating elements that are substantially oriented in predetermined separation directions, defining edges of the graph between the vertices corresponding to the separating elements, and defining field separators corresponding to the edges of the graph.