1. A method, implemented by a computer, for generating a vector codebook providing low data compression computational effort starting from a vector codebook comprising a set of N reference vectors each comprising Q features, wherein N and Q are positive integers higher than 1, comprising the steps of: a) sorting, by the computer, the set of N reference vectors in ascending or descending order with respect to values associated with a predetermined feature of the set of N reference vectors; b) subdividing, by the computer, the set of sorted reference vectors in sub-sets; c) associating, by the computer, with each of said sub-sets a respective threshold value for the predetermined feature; d) sorting, by the computer, the reference vectors of each of said sub-sets in ascending or descending order with respect to values associated with a further predetermined feature of the set of N reference vectors; e) subdividing, by the computer, each of said sub-sets of sorted reference vectors in further sub-sets; f) associating, by the computer, with each of said further sub-sets a respective further threshold value for the further predetermined feature; and g) extending at least one of the sub-sets obtained in step b) with at least one reference vector of an adjacent sub-set, wherein steps d) and e) being carried out on the sub-sets extended according to step g), wherein the set of N reference vectors sorted in step a) are arranged in a table form including N rows and Q columns, each row representing a reference vector having Q features.