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