PLOT /SCALING

        [GREG2\]PLOT /SCALING Type [Low_cut High_cut]

    Defines the type of transfer function to be used. Type can be  LIN(EAR),
    LOG(ARITHMIC)  of  EQU(ALIZATION),  and the Low_cut and High_cut are the
    lowest and highest represented values respectively. The default ``cuts''
    are  the image extrema. The current cuts are stored in variable LCUT and
    HCUT. The current scaling (as an integer)  is  stored  in  the  variable
    SCALING.  The LOG transfer function computes the logarithm of the pixels
    values, so does not like negative  or  null  pixels.   The  EQUalization
    scaling  tries its best to put the same number of pixels in each slot of
    the color table,  thus  increasing  immensely  the  visibility  of  low-
    contrast  images.  This scaling mode has problem (and warns user) when a
    large number of pixels have exactly the same value (i.e., no contrast at
    all). Beware that most "real" images are obtained with receivers working
    with a small number (11 to 16)  bits,  thus  restricting  the  range  of
    available Real numbers in the data.

    The SIC  variables  EQUAL_NLEV  and  EQUAL_LEV  contain  the  number  of
    different  levels computed in EQUALIZATION mode, and the values of these
    levels. Useful to know which contour levels to draw, and  necessary  for
    the WEDGE command.