A Morlet wavelet [Une ondelette de Morlet].

                                      2        2
                                 | X |    | Y |
                                 |---|  + |---|
                                 | d |    | d |                   X            Y
                              - -----------------  i.|k|.[cos(t).--- + sin(t).---]
                                        2                         d            d
                    F(X,Y) = e                   .e

                    d = 0.10 (dilatation)
                    k = 6    (number of periods)
                    t = pi/2 (rotation)