1. A method of representing an object appearing in an image, wherein the object appears in the image with a first two-dimensional outline, by processing signals corresponding to the image, the method comprising deriving a view descriptor of the first outline of the object and deriving at least one additional view descriptor of the outline of the object in a different view, and associating the two or more view descriptors to form an object descriptor, wherein the view descriptors are derived using a curvature scale space representation.