1. A system for detecting the orientation of an article comprising: memory means for storing data relating to distances between each one of a plurality of feature points of the article and each of the others of said plurality of feature points; a camera for picking up an image of the article to give image data, means, electrically connected to said camera, for obtaining from the image data data relating to the distances of at least two of the feature points of the article from other feature points, means, operatively connected to said memory means and said obtaining means, for identifying said at least two feature points by checking the data relating to the distances of said at least two feature points from other feature points with reference to the stored data relating to the distances between each one of a plurality of feature points and the other feature points, and means, operatively connected to said identifying means, for determining the orientation of the article based on a direction through said at least two identified feature points.