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PLOT /SCALING

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

    Defines  the  type  of transfer function to be used. Type can be LINear,
    natural LOGarithmic, or EQUalization. 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 the variable array
    CURIMA%SCALE.  The current scaling (as an integer code) is stored in the
    variable CURIMA%SCALING. The LOG transfer function  computes  the  loga-
    rithm 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 visibili-
    ty  of low-contrast images. This scaling mode has problem (and warns us-
    er) 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 re-
    ceivers working with a small number (11 to 16) of bits, thus restricting
    the range of available Real numbers in the data.

    The   SIC   variables   CURIMA%EQUAL%NLEV,  CURIMA%EQUAL%LEV  and  CURI-
    MA%EQUAL%HIST contain the number of different levels computed in  EQUAL-
    IZATION  mode,  the  values of these levels, and the number of pixels in
    each level, respectively. Useful to know which contour levels  to  draw,
    and necessary for the WEDGE command.


Gildas manager 2020-12-02