C @(#)normalize.for	17.1.1.1 (ES0-DMD) 01/25/02 17:19:21
C===========================================================================
C Copyright (C) 1995 European Southern Observatory (ESO)
C
C This program is free software; you can redistribute it and/or 
C modify it under the terms of the GNU General Public License as 
C published by the Free Software Foundation; either version 2 of 
C the License, or (at your option) any later version.
C
C This program is distributed in the hope that it will be useful,
C but WITHOUT ANY WARRANTY; without even the implied warranty of
C MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
C GNU General Public License for more details.
C
C You should have received a copy of the GNU General Public 
C License along with this program; if not, write to the Free 
C Software Foundation, Inc., 675 Massachusetss Ave, Cambridge, 
C MA 02139, USA.
C
C Corresponding concerning ESO-MIDAS should be addressed as follows:
C	Internet e-mail: midas@eso.org
C	Postal address: European Southern Observatory
C			Data Management Division 
C			Karl-Schwarzschild-Strasse 2
C			D 85748 Garching bei Muenchen 
C			GERMANY
C===========================================================================
C
C +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
C.COPYRIGHT: Copyright (c) 1987 European Southern Observatory,
C                                         all rights reserved
C.IDENTIFICATION: NORMALIZE
C.LANGUAGE:       F77+ESOext
C.AUTHOR:         O.-G. Richter
C.KEYWORDS:       bulk data frame, normalization, sky background
C.PURPOSE:        Normalizes an image calibrated to relative intensity to
C                 a sky background of 1.0
C.ALGORITHM:      Histogram of max. 5000 pixels is formed and MEAN, MODE and
C                 MEDIAN are computed. The third mode is taken to be
C                 the sky background. All pixels are now divided by
C                 this background value thereby normalizing the frame
C                 to a sky background 1.0.
C.INPUT/OUTPUT:   IN_A/C/1/60    input frame
C                 OUT_A/C/1/60   output frame - if omitted, input frame 
C                                will be updated
C                 INPUTR/R/1/2   truncation values (min,max),
C                                min > max indicates no truncation wanted
C                 INPUTR/R/3/4   control values for array CRMD
C.NOTE:           Resulting background will be displayed + stored into
C                 descriptor FLAT_SKY/R/1/1 and key OUTPUTR/R/11/4 as well
creation
C.VERSION:        830712 OGR creation
C.VERSION:        ?????? KB  ???
C.VERSION         870928 RHW ST interfaces
C.VERSION:        871123 RHW ESO-FORTRAN Conversion
C.VERSION:        900508 RHW Portable ST interface
C -----------------------------------------------------------------------
      PROGRAM NRMLZ
C
      IMPLICIT    NONE
C
      INTEGER     MADRID
      INTEGER     PNTR1,PNTR2,IPNTR,IMF1,IMF2,IMF
      INTEGER     IAC,ISTAT,N
      INTEGER     NCHA,NCHB
      INTEGER     KUN(1),KNUL
      INTEGER     NAXIS,NPIX(2)
C
      DOUBLE PRECISION START(2),STEP(2)
      REAL        BGRD(4),CRMD(4),CUTS(4),TRUNC(4)
C
      CHARACTER   FRAMEA*60,FRAMEB*60
      CHARACTER   CUNIT*48,IDENT*72,HIST*80,OUTPUT*80
C
      INCLUDE     'MID_INCLUDE:ST_DEF.INC/NOLIST'
      COMMON      /VMR/MADRID(1)
      INCLUDE     'MID_INCLUDE:ST_DAT.INC/NOLIST'
C
      DATA        HIST/' '/
 9000 FORMAT('background value = ',G15.7)
C
C *** begin code
      CALL STSPRO('NORMALIZE')                                    ! init MIDAS
C
C *** read keywords
      CALL STKRDC('IN_A',1,1,60,IAC,FRAMEA,KUN,KNUL,ISTAT)
      CALL STKRDC('OUT_A',1,1,60,IAC,FRAMEB,KUN,KNUL,ISTAT)
      CALL STKRDR('INPUTR',1,2,IAC,TRUNC,KUN,KNUL,ISTAT)
      CALL STKRDR('INPUTR',3,4,IAC,CRMD,KUN,KNUL,ISTAT)
C
      IF (FRAMEA.NE.FRAMEB) THEN
         CALL STIGET(FRAMEA,D_R4_FORMAT,F_I_MODE,F_IMA_TYPE,
     2               2,NAXIS,NPIX,START,STEP,IDENT,CUNIT,
     +               PNTR1,IMF1,ISTAT)
         CALL STIPUT(FRAMEB,D_R4_FORMAT,F_O_MODE,F_IMA_TYPE,
     2               NAXIS,NPIX,START,STEP,IDENT,CUNIT,
     2               PNTR2,IMF2,ISTAT)
         CALL STDCOP(IMF1,IMF2,3,' ',ISTAT)
         CALL CPFRAM(MADRID(PNTR1),MADRID(PNTR2),NPIX(1),NPIX(2))         ! copy
         IMF    = IMF2
         IPNTR  = PNTR2

      ELSE                                      ! use input image frame directly
         CALL STIGET(FRAMEA,D_R4_FORMAT,F_IO_MODE,F_IMA_TYPE,
     2               2,NAXIS,NPIX,START,STEP,IDENT,CUNIT,
     +               IPNTR,IMF,ISTAT)
      END IF
C
      CALL NORMAL(MADRID(IPNTR),NPIX,CRMD,BGRD)                  ! now normalize
C
C *** display + store results
      WRITE (OUTPUT,9000) BGRD(1)
      CALL STTPUT(OUTPUT,ISTAT)
      NCHA = INDEX(FRAMEA,' ')-1
      NCHB = INDEX(FRAMEB,' ')-1
      HIST = FRAMEB(1:NCHB)//' = normalized('//FRAMEA(1:NCHA)//')'   ! app hist.
      CALL STDWRC(IMF,'HISTORY',1,HIST,-1,80,KUN,ISTAT)
      CALL STDWRR(IMF,'FLAT_SKY',BGRD,1,1,KUN,ISTAT)       ! backgrnd in keyword
      CALL STKWRR('OUTPUTR',BGRD,11,4,KUN,ISTAT)
      CALL STDRDR(IMF,'LHCUTS',1,4,IAC,CUTS,KUN,KNUL,ISTAT)
 
      DO 10 N = 1,4
         CUTS(N) = CUTS(N)/BGRD(1)
   10 CONTINUE
 
      IF (TRUNC(1).GE.TRUNC(2)) THEN
         CALL STDWRR(IMF,'LHCUTS',CUTS,1,4,KUN,ISTAT)
      ELSE
         CALL TRUNCY(MADRID(IPNTR),NPIX,TRUNC)
         CUTS(1) = MAX(CUTS(1),TRUNC(1))
         CUTS(2) = MAX(CUTS(2),TRUNC(2))
         CUTS(3) = MAX(CUTS(3),TRUNC(3))
         CUTS(4) = MAX(CUTS(4),TRUNC(4))
         CALL STDWRR(IMF,'LHCUTS',CUTS,1,4,KUN,ISTAT)
      ENDIF
C
      CALL STSEPI
      END