PRO iflat,list,dd,ff
;
;Flatfielding of infrared frames.
;INPUT:  list - string array with names of raw files
;	 dd - darkfield array (float)
;	 ff - flatfield array (float)
;OUTPUT: plain binary files, 224x224, integer, values multiplied by 10000,
;	 name 'ifXX.seq', where XX is the date and seq the frame number,
;	 equal to the subscript of list array (beginning from 0).
;CALLED: readfits.pro and its subroutines to read raw images,
;	 wherenan.pro to fix division by zero

;*****************path & name to be modified *****************

path='25jun/'
name=path+'if25.'

;*************************************************************

	window,0,xsiz=224,ysiz=224
fd=ff-dd		;flatfield - dark
si=size(list)
for i=0,si(1)-1 do begin
  im=readfits(path+list(i))
  byteorder,im
  im=im(6:229,6:229)		;setting working field
  im=(im-dd)/fd			;this is float
  w=wherenan(im,cn)		;when dividing by zero,
  if cn ne 0 then im(w)=1.	; set the result to 1 (mean value)
  im=im > 0.6		;setting reasonable intensity limits
  im=im < 1.2
  im=fix(10000*im)	;this is integer scaled to 10000
  openw,1,name+strtrim(i,2)
  print, 'Processing ',list(i),' , writing ',name+strtrim(i,2)
  writeu,1,im
  close,1
	tvscl,im
endfor

END