;+
; NAME	sqrtfts2gif.pro
;
; PURPOSE	Perform square root scaling on images.
;
; SYNTAX	sqrtfts2gif, list
;
; OUTPUT	Images in GIF format.
;
; HISTORY	Andrew L. Stanger   HAO/NCAR   6 December 1999
;-

pro sqrtfts2gif, fts_list

red = bindgen (256)
green = red
blue  = red
fts_name = ''
close,1

lct, '/home/stanger/color/bwy5.lut'		; color table.

lct, '/home/stanger/color/bwy2.lut'		; color table.
lct, '/home/stanger/color/bwy.lut'		; color table.
lct, '/home/stanger/color/qualy.lut'		; color table.
lct, '/home/stanger/color/qual.lut'		; color table.

tvlct, red, green, blue, /get

;--- File list loop.

CLOSE, 1
OPENR, 1, fts_list				; Open list file.
WHILE (NOT EOF (1)) DO	$
BEGIN	;{

   ;--- Read FITS image header & pixel data.

   READF, 1, fts_name				; Get FITS file name.
   print, 'fts_name: ', fts_name

;   READ_GIF, fts_name, fts_img			; Read GIF image.

   fts_img = readfits (fts_name, hdu)		; Read FITS image.

   ;--- Extract information from header.

;   fts_min = MIN (fts_img, max=fts_max)

   fts_min = fxpar (hdu, 'DISPMIN')
   fts_max = fxpar (hdu, 'DISPMAX')
   img_min = fxpar (hdu, 'DATAMIN')
   img_max = fxpar (hdu, 'DATAMAX')

   offset = 5.0E-7				; Mk3
   offset = 1.2E-6				; Mk4
   offset = 1.0E-6				; Mk4
   offset = 0.0E-6				; Mk4 bwy2.lut
   offset = 0.5E-6				; Mk4 qual.lut
   offset = 0.2E-6				; Mk4 qual.lut

   i_min = 0.0
   i_max = (img_max - fts_max) / 2.0 + fts_max
   i_max = fts_max + offset

   ;--- Compute square root of image.

   new_img = SQRT (fts_img > 0.0) * 1.5			; Compute square root.
   new_img = ((fts_img > 0.0) ^ (0.25)) * 1.5

   new_img = ((fts_img > 0.0) ^ (0.25))			; bwy.lut
   new_img = ((fts_img > 0.0) ^ (0.40))			; qual.lut
   new_img = ((fts_img > 0.0) ^ (0.30))			; bwy2.lut
   new_img = ((fts_img > 0.0) ^ (0.25))			; bwy2.lut
   new_img = ((fts_img > 0.0) ^ (0.50))			; qual.lut

;   new_min = MIN (new_img, max=new_max)		; Get image min/max.
   new_min = SQRT (i_min)
   new_max = SQRT (i_max)
   new_min = i_min ^ (0.50)
   new_max = i_max ^ (0.50)

   print, FORMAT = '("fts_min/max: ", E10.3, E10.3)', fts_min, fts_max
   print, FORMAT = '("img_min/max: ", E10.3, E10.3)', img_min, img_max
   print, FORMAT = '("new_min/max: ", E10.3, E10.3)', new_min, new_max

;   IF (new_min LT 0.0) THEN	$			; Symmetric about zero.
;      IF (-new_min LT new_max) THEN new_min = -new_max  ELSE new_max = -new_min
;   print, FORMAT = '("new_min/max: ", E10.3, E10.3)', new_min, new_max

;   new_min = -5.00e-8
;   new_max =  5.00e-8
;   print, FORMAT = '("new_min/max: ", E10.3, E10.3)', new_min, new_max

   ;--- Convert to byte pixels.
   ;--- Display image.

   byt_img = BYTSCL (new_img, min=new_min, max=new_max, top=255)
   TV, byt_img						; Display image.

   ;--- Write newference image to disk.

   fpos = strpos (fts_name, '.fts')
   new_name = strmid (fts_name, 0, fpos) + '.sqrt.gif'
   print, 'Write sqrt image : ', new_name
   WRITE_GIF, new_name, byt_img, red, green, blue	; Write new image.
END	;}

CLOSE, 1
END