FUNCTION DIcal_realToInt, in, fitsHdr

;;-----------------------------------------------------------------------------
;; PURPOSE:
;;	Used in the DI Calibration Pipeline.
;;	Scales the image from real values to integer values by multiplying the
;;	the image by 10^n. N is recorded in fitsHdr. Saturated pixels receive
;;	the value 2^16-1 since we cannot represent Infinity in integers
;;
;; CALLING SEQUENCE:
;;	out = DIcal_realToInt(in, fitsHdr)
;;
;; REQUIRED INPUTS:
;;	in - The image to which this pipeline element is going to be applied
;;	fitsHdr - The FITS header for the image
;;
;; OUTPUTS:
;;	RETURN - the image after going through this calibration step
;;	fitsHdr - the new FITS header with the muliplication power recorded
;;
;; OPTIONAL INPUT KEYWORDS:
;;
;; EXAMPLE:
;;      IDL> imgOut = DIcal_realToInt(imgIn, fitsHdr)
;;
;; PROCEDURES USED (i.e. called directly!):
;;
;;
;; MODIFICATION HISTORY:
;;   2004-05-24  M. Desnoyer    Created
;;
;;-----------------------------------------------------------------------------

;; Do error handling 
;CATCH, error
error=0

IF error NE 0 THEN BEGIN
	CATCH, /CANCEL
	message, 'Scale to Halfword - ' + !ERROR_STATE.MSG, /NONAME
ENDIF

;; Find all the saturated pixels
sat = where(finite(in,/INFINITY) EQ 1)

;; Find all the bad pixels
bad = where(finite(in,/NAN) EQ 1)

;; Find all the good pixels
good = where(finite(in) NE 0)

;; Determine the scaling factor (ie the highest value of N such that 
;; max*10^2<=2^16)
N = UINT(alog10((double(2)^16)/max(in[good])))

;; Record the scaling factor in the fits file TODO

;; Scale the image, making sure that all values are non-negative
dims = size(in,/dimensions)
out = uintarr(dims[0],dims[1],/nozero)
out[sat] = 2^16-1
out[bad] = 0
out[good] = (in[good] > 1)*10^N

RETURN, out
END