;------------------------------------------------------------------
;+
; NAME:
;	LCQXSETUP
; PURPOSE:
;	This procedure accepts two BBSO VMG FITS files, one V
;	image (magnetogram) and one J or I image (direct image).
;	A 50 x 50 boxcar smoothed image is generated and subtracted
;	from the magnetogram to remove large-scale non-uniformities
;	in the magnetogram (often due to KDP fringes).  Then,
;	both the V and the J (or I) images are rebinned from
;	512 x 481 to 512 x 384 to make the pixels square.
;	The resulting images are written back to the disk as FITS
;	images.  The letters "ss" are put in the file name before
;	the extension (before the first "." in the file name or
;	at the end of the name).
;
;	Note that the old IRAF version deleted the original FITS
;	files.  This version does not.
;
;	Modified version for old QX images.  Assumes 12-bit images.
; CATEGORY:
;	POLAR
; CALLING SEQUENCE:
;	LCQXSETUP,vfile,jfile,zpoff
; INPUTS:
;	vfile = file name for input magnetogram (FITS format).
;	jfile = file name for input direct image (FITS format).
;	zpoff = zero-point offset for Quantex I image.
; KEYWORD PARAMETERS:
; OUTPUTS:
;	vfiless = FITS file of rebinned and "flattened" magnetogram
;		  This image is also divided by intensity.
;	jfiless = FITS file of rebinned direct image
; COMMON BLOCKS:
; NOTES:
; MODIFICATION HISTORY:
;	J. Varsik,	18 Dec. 1995 --- Modified from LCSETUP
;					 for old QX images.
;-
;-------------------------------------------------------------------

pro lcqxsetup,vfinam,jfinam,zpoff

    ; Display IDL header if help is required.
    if (keyword_set(help)) then begin
      get_idlhdr,'lcqxsetup.pro'
      goto,finishup
    endif

    ; Make output file names.
    dotpos = STRPOS(vfinam,".")
    vflen = dotpos
    vfin1 = STRMID(vfinam,0,vflen)
    exlen = STRLEN(vfinam) - vflen
    ext = STRMID(vfinam,dotpos,exlen)
    vfonam = vfin1 + 'ss' + ext

    dotpos = STRPOS(jfinam,".")
    jflen = dotpos
    jfin1 = STRMID(jfinam,0,jflen)
    exlen = STRLEN(jfinam) - jflen
    ext = STRMID(jfinam,dotpos,exlen)
    jfonam = jfin1 + 'ss' + ext

    ; Read V file
    vi = READFITS(vfinam,vih,/NOSCALE)
    vib = make_array(640,640,/byte,value=128)
    vib(64,64) = vi

    ; Unwrap, subtract 128, rescale
    viuw = unwrap(fix(vib))
    vii = viuw - 128
    vix = 16 * vii

    ; Generate boxcar smoothed file and subtract.
    s = SMOOTH(vix,50)
    vo = vix - s

    vos = vo(64:575,64:544)
    ; Read J file
    ji = READFITS(jfinam,jih,/NOSCALE)

    ; Rebin images
    vs = fix(CONGRID(vos,512,384))
    js = byte( CONGRID(ji,512,384))

    ; Divide by intensity
    vsd = fix((256.0 * vs)/(fix(js) + zpoff))

    ; Write files
    CHECK_FITS,vsd,vih,/UPDATE,/FITS
    CHECK_FITS,js,jih,/UPDATE,/FITS
    WRITEFITS,vfonam,vsd,vih
    WRITEFITS,jfonam,js,jih
    
    finishup:

    return
end