Method and apparatus for generating a function to extract a global characteristic value of a signal contents

摘要

The invention enables to generate a general function (4) which can operate on an input signal (Sx) to extract therefrom a predetermined global characteristic value (DVex) expressing a feature of the information (De) conveyed by that signal.;It operates by:generating automatically compound functions (CF1- CFn), each compound function being composed of at least one of a set of elementary functions (EF1, EF2, ..), by using means (22, 25) that handle said elementary functions as a symbolic object, andoperating said compound functions on at least one reference signal (S1-Sm) having a pre-attributed global characteristic value (Dgt1-Dgtm) serving for evaluation, by using means (22, 27) that process said elementary functions as executable operators,determining the correlation between the values (Dij) extracted by those compound functions as a result of operating on said reference signal and the pre-attributed global characteristic value (Dgt1-Dgtm) of said reference signal, andselecting said general extraction function (4) among those compound functions for which said correlation is relatively high.;The invention can be used, for instance, for the automatic extraction of audio/music descriptors from their signals contained as music file data.