PLOT /SCALING

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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 logarithm of  the  pixel  values.
        There  can be negative pixel values as long as the low and high cuts re-
        main positive. If one or two cuts are negative or null, they will be im-
        plicitly  replaced  with a better suited positive value (lowest positive
        or highest positive value depending on the cut).

        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.