Level 2 Help for FFT1PIX

 In the forward mode, only one input is allowed.

 In the reverse mode, up to three input files are allowed.  The first
 input  is  the  picture on which to operate, the second input is the
 modified  amplitude picture, and the third input is (optionally) the
 modified phase picture.

 Up to two outputs are allowed.  No output is needed if only the page
 plot is desired.

 If  only one output is provided, the type of output is controlled by
 the TYPE parameter.

 If  two  output  files  are given, TYPE is ignored, and an amplitude
 picture  is  written to the first output, and a phase picture to the
 second. 

 If  only  one  output  is  specified, then TYPE controls the type of
 output;  AMPL  specifies  an amplitude output, and PHASE specifies a
 phase output.

 If  LOG  is  specified,  then the logarithm of the amplitude picture
 output.   This  is  recommended  if  the  amplitude picture is to be
 MASK'ed or FOTO'ed.

 If  SPIKE  is  given,  then  each  line  of the amplitude picture is
 normalized  to  the  SPIKE'th peak for that line.  If NORMAL is also
 specified,  then each line is normalized to the SPIKE'th peak of the
 first line.  (default = dc term)

 AMPLITUDE PICTURE NORMALIZED TO SPECIFIED SPIKE OF FIRST LINE.

 THE SIGN OF THE PHASE ANGLE IS IGNORED IN THE OUTPUT PHASE 
 PICTURE.

 THE COMPLEX CONJUGATE OF THE TRANSFORM IS INCLUDED IN BOTH
 THE AMPLITUDE AND THE PHASE PICTURES.

 PLOT,L1,L2, ------ AN AMPLITUDE PLOT IS PRODUCED OF LINES L1,
 L2,... ETC. (MAX OF 20)  THIS IS SIMILAR TO THE OUTPUT 
 OF POWER, ONLY LINE BY LINE.

 AVG,I ----- THE I LINES PRECEDING LINE L ARE AVERAGED IN THE

 PSPIKE,I ----- PAGE PLOT NORMALIZED TO I'TH PEAK (DEFAULLT = 2)

 FREQUENCY GIVEN AS X - AXIS OF PAGE PLOT. (DEFAULT = TERM 
 NUMBER OF FOURIER COEF.)

 REVERSE MODE. THE PRIMARY INPUT IS THE COMPLEX*8 DATA SET FROM
 FFT1. THE SECONDARY AND THIRD INPUT DATA SETS ARE REFERENCE 
 AMPLITUDE AND/OR PHASE PICTURES BY WHICH THE TRANSFORM WILL
 BE MODIFIED AND WRITTEN ON THE OUTPUT DATA SET.
 (IN THE REVERSE MODE, IF ANY OF THE PARMS "LOG", "SPIKE,I", "NORMAL",
  "PLOT,L1,L2", "AVG,I", "PSPIKE,I", "FREQ", IS SPECIFIED, 
  IT DENOTES THAT THE SPECIFIED PARM WAS USED IN THE FORWARD
  MODE. THE PARM "CONJ" IS NOT NORMALLY USED IN THE REVERSE 
  MODE. IF USED, IT DENOTES THAT THE COMPLEX CONJUGATE OF 
  THE TRANSFORM IS TO BE MODIFIED INDEPENDENTLY .  THIS COULD
  PRODUCE UNPREDICTABLE RESULTS.)

 DC,R ----- THE DC TERM OF EACH LINE WILL BE INCREASED BY AN
 AMOUNT R. THIS WILL CAUSE THE AVERAGE GRAY LEVEL OF THE 
 PICTURE TO BE INCREASED BY R AFTER THE INVERSE TRANSFORM.

 GAIN,R ----- A GAIN FACTOR OF R IS APPLIED TO EACH LINE.
 THIS WILL HAVE THE EFFECT OF A CONTRAST STRETCH AFTER
 THE INVERSE TRANSFORM.