%N pgsitf %F $MIR/src/pgsitf.f
%D Set image transfer function
%B
      SUBROUTINE PGSITF (ITF)
      INTEGER  ITF

 Set the Image Transfer Function for subsequent images drawn by
 PGIMAG, PGGRAY, or PGWEDG. The Image Transfer Function is used
 to map array values into the available range of color indices
 specified with routine PGSCIR or (for PGGRAY on some devices)
 into dot density.

 Argument:
  ITF    (input)  : type of transfer function:
                      ITF = 0 : linear
                      ITF = 1 : logarithmic
                      ITF = 2 : square-root
