C++*********************************************************************
C
C    CHANGEVAL.F  
C                     ADDED NREPL                 OCT 2007 ARDEAN LEITH  
C                
C **********************************************************************
C=* FROM: SPIDER - MODULAR IMAGE PROCESSING SYSTEM.   AUTHOR: J.FRANK  *
C=* Copyright (C) 1985-2007  Health Research Inc.                      *
C=*                                                                    *
C=* HEALTH RESEARCH INCORPORATED (HRI),                                *   
C=* ONE UNIVERSITY PLACE, RENSSELAER, NY 12144-3455.                   *
C=*                                                                    *
C=* Email:  spider@wadsworth.org                                       *
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 the *
C=* 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 GNU  *
C=* General Public License for more details.                           *
C=*                                                                    *
C=* You should have received a copy of the GNU General Public License  *
C=* along with this program; if not, write to the                      *
C=* Free Software Foundation, Inc.,                                    *
C=* 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.      *
C=*                                                                    *
C **********************************************************************
C
C    CHANGEVAL(LUN1,LUN2,NSAM,NROW,NSLICE)
C
C    PURPOSE:  CHANGE A SPECIFIC VALUE IN AN IMAGE FILE
C
C    CALLED BY:   UTIL2
C
C--********************************************************************

	SUBROUTINE CHANGEVAL(LUN1,LUN2,NSAM,NROW,NSLICE)

        INCLUDE 'CMBLOCK.INC'
        INCLUDE 'CMLIMIT.INC'

        COMMON /IOBUF/ BUF(NBUFSIZ)

	REAL        NEWVAL

	CALL RDPRM2S(OLDVAL,NEWVAL,NOT_USED,'OLD AND NEW VALUES',IRTFLG)
	IF (IRTFLG .LT. 0)  RETURN

        NREPL = 0
        IRECT = 0

        DO J=1, NSLICE    
	   DO I=1,NROW
              IRECT = IRECT + 1
	      CALL REDLIN(LUN1,BUF,NSAM,IRECT)

	      DO K=1,NSAM
	         IF (BUF(K) .EQ. OLDVAL)  THEN
                    BUF(K) = NEWVAL
                    NREPL  = NREPL + 1
                 ENDIF
               ENDDO

              CALL WRTLIN(LUN2,BUF,NSAM,IRECT)
           ENDDO
        ENDDO

        CALL SETPRM(LUN2,NSAM,NROW,0.,0.,0.,'U')

        FREPL = FLOAT(NREPL)
        CALL REG_SET_NSEL(1,1, FREPL,0.0, 0.0, 0.0, 0.0,IRTFLG)

        WRITE(NOUT,*) ' PIXELS REPLACED: ',NREPL
 	END