C ++********************************************************************
C                                                                      *
C  MD2                                                                 *
C                                                                      *
C **********************************************************************
C=* FROM: SPIDER - MODULAR IMAGE PROCESSING SYSTEM.   AUTHOR: J.FRANK  *
C=* Copyright (C) 1985-2005  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  MD2(X,NSAM,NROW,L,K,MODE,LUNO)                                                                 *
C                                                                      *
C  PURPOSE:  MEDIAN FILTER ON IMAGE                                                            *
C                                                                      *
C  PARAMETERS:                                                         *
C                                                                      *
C IMAGE_PROCESSING_ROUTINE                                             *
C                                                                      *
C        0         2         3         4         5         6         7 *
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C***********************************************************************

        SUBROUTINE  MD2(X,NSAM,NROW,L,K,MODE,LUNO)

        REAL,    DIMENSION(NSAM,NROW) :: X
C       AUTOMATIC ARRAYS
        REAL,    DIMENSION(NSAM)      :: Y
        REAL,    DIMENSION(K)         :: A
        CHARACTER(LEN=1)              :: MODE

        LH  = L/2
        K21 = K/2+1
        DO J=1,NROW
           IF (MODE .EQ. 'C')  THEN
              DO I=1,NSAM
                 LB = 0
                 DO M=-LH,LH
                    IF (M .NE. 0)  THEN
                       LB    = LB + 1
                       A(LB) = X(I,MOD(J+M+NROW-1,NROW)+1)
                       LB    = LB + 1
                       A(LB) = X(MOD(I+M+NSAM-1,NSAM)+1,J)
                    ELSE
                       LB    = LB + 1
                       A(LB) = X(I,J)
                    ENDIF
                 ENDDO

                 CALL FSORT(A,K)
                 Y(I) = A(K21)
              ENDDO
           ELSE
              DO I=1,NSAM
                 LB = 0
                 DO MJ=-LH,LH
                    MJM = MOD(J+MJ+NROW-1,NROW)+1
                    DO MI=-LH,LH
                       LB    = LB + 1
                       A(LB) = X(MOD(I+MI+NSAM-1,NSAM)+1,MJM)
                    ENDDO
                 ENDDO
                 CALL FSORT(A,K)
                 Y(I) = A(K21)
              ENDDO
           ENDIF
           CALL  WRTLIN(LUNO,Y,NSAM,J)
        ENDDO
        END