1. A method of deriving a representation of an image by processing signals corresponding to the image, the method comprising: deriving a Trace transform of the image; processing said Trace transform to obtain a plurality of intermediate representations of parts of the image, and deriving the representation of the image from the intermediate representations, wherein the intermediate representations are obtained by selecting parts of the Trace transform, and the step of selecting parts of the Trace transform includes defining bands of values in the Trace transform, each band defined by a predetermined range of a distance parameter of the Trace transform.