1. A method of compressing a block of image elements, each image element having an associated feature vector, said method comprising the steps of: determining, based on at least a portion of said feature vectors, at least four base vectors with the proviso that if four base vectors are determined, said four base vectors are not positioned in the corners of a right-angled parallelogram in a vector space; defining an order of said at least four base vectors; selecting at least one pair of base vectors of said at least four base vectors as neighboring base vectors according to said defined order; determining, for a selected pair of base vectors, at least one additional vector based on said pair of base vectors; selecting, for at least one image element and based on a feature vector associated with said image element, a vector among said at least four base vectors and said at least one additional vector as a representation of said feature vector; and assigning, to said at least one image element, a vector identifier associated with said selected vector.