1. An apparatus for detecting overlapping flat objects, each object having flat sides and narrow sides, comprising: a doubles detector configured to derive at least one feature of an object; a first imaging unit configured to produce an electronic image of a first flat side of the object; a second imaging unit configured to produce an electronic image of a second flat side of the object; a determination facility coupled to the first imaging unit and the second imaging unit to receive the electronic images, and to derive at least one further feature of the object; and a decision facility coupled to the doubles detector and the determination facility to receive the least one feature and the at least one further feature of the object, and to determine whether the object is a single object or a number of objects.