HISTO_DOUBLE

##
HISTO_DOUBLE

            HISTO_DOUBLE

        Computes the histogram of an image (Y_image) as  a  function  of  a sec-
        ond  one  (Z_image).   This  gives  an  information   similar   to,  but
        slightly different from  the  cross  histogram  (cf  HISTO_CROSS).   The
        program  computes  histogram  of  the mean value and standard deviation.
        The result is a table of 4 Columns, in which
          1)  the  first column contains the mean value of the Y_image  (average
            of all pixels in the Y_image for which the Z_image value is included
            in the corresponding slot)
          2) the second the standard deviation (of the Y_image values).
          3)  the  third  the number of pixels of the Y_image  used  to  compute
            the mean and deviation.
          4) the fourth column contains the histogram abscissa   (actual   value
            of the input Z_image)