		MFILTERS -- Package of MEDIAN/MODAL Filtering Tasks

The mfilters package contains a set of routines for median/modal filtering
images using a variety of techniques. The box median/modal filters all have
two new parameters zloreject and zhireject that can be used to eliminate
data outside a given data range from the median/mode computations. The ring
median/modal filters are new. A list of the eight tasks in the package
is shown below.

  	fmedian - Quantize and box median filter a list of 1D or 2D images
          fmode - Quantize and box modal filter a list of 1D or 2D images
       frmedian - Quantize and ring median filter a list of 1D or 2D images
         frmode - Quantize and ring modal filter a list of 1D or 2D images
         median - Median box filter a list of 1D or 2D images
           mode - Modal box filter a list of 1D or 2D images
        rmedian - Ring median filter a list of 1D or 2D images
          rmode - Ring modal filter a list of 1D or 2D images



All eight task will become part of the IMAGES package when IRAF 2.11 is
released.

	       RELEASE INFORMATION

===============================================================================
First archive release: Nov 28, 1995
===============================================================================


	INSTALLATION INSTRUCTIONS FOR THE MFILTERS PACKAGE

The installation instructions that follow assume that you have copied the
tar format MFILTERS archive onto your host machine.  The method you use to
copy the file (or remotely access the tar file) is OS dependent and is not
discussed in this document.  If you have any questions, please contact the
author at davis@noao.edu or the IRAF group at iraf@noao.edu,
NOAO::IRAF (5355::IRAF) or call the IRAF HOTLINE at 520-318-8160.

[1] The package is distributed as a tar archive; IRAF is distributed
    with a tar reader.  The tar archive may be obtained by magnetic
    tape or anonymous ftp.  For magnetic tape go to step [2] and when
    reading the tar archive simply mount the tape and use the tape
    device name for the archive name in step [4].  To obtain the package
    via ftp (assuming a UNIX computer):

	% ftp iraf.noao.edu (140.252.1.1)
	login: anonymous
	password: [your email address]
	ftp> cd iraf/extern
	ftp> get mfilters.readme
	ftp> binary
	ftp> get mfilters.tar.Z
	ftp> quit
	% uncompress mfilters.tar

    The mfilters.readme file contains these instructions.  Special arrangements 
    can be made for sites that don't have access to internet but could copy 
    the uncompressed archive over SPAN.

[2] Create a directory to contain the MFILTERS external package files.  This
    directory should be outside the IRAF directory tree and must be owned
    by the IRAF account.  In the following examples, this root directory is
    named usr1:[mfilters] (VMS) or  /local/mfilters/ (UNIX).  Make the
    appropriate file name substitutions for your site.

[3] Log in as IRAF and edit the extern.pkg file in the hlib$ directory to
    define the package to the CL.  From the IRAF account, outside the CL,
    you can move to this directory with the commands:

	$ set def irafhlib	# VMS example
	% cd $hlib		# UNIX example

    Define the environment variable mfilters to be the pathname to the
    mfilters root directory.  The '$' character must be escaped in the VMS
    pathname; UNIX pathnames must be terminated with a '/'.  Edit
    extern.pkg to include:

	reset mfilters	= usr\$1:[mfilters]   	# VMS example
	reset mfilters  = /local/mfilters/	# UNIX example
	task  $mfilters.pkg = mfilters$mfilters.cl

    Near the end of the hlib$extern.pkg file, update the definition of helpdb
    so it includes the mfilters help database, copying the syntax already used
    in the string.  Add this line before the line containing a closing quote:
        
                ,mfilters$lib/helpdb.mip\

    NOTE: In IRAF V2.8 the length of the helpdb string cannot exceede 160 
    characters.  A helpdb string longer than 160 characters will cause the
    CL startup process to fail.

[4] Log into the CL from the IRAF account and unpack the archive file.  Change
    directories to the mfilters root directory created above and use 'rtar':

	cl> cd mfilters
	cl> softools
	cl> rtar -xrf <archive>  where <archive> is the host name of the
				 archive file or the IRAF tape
				 device for tape distributions.

   On VMS systems, an error message will appear ("Copy 'bin.generic' to
   './bin fails") which can be ignored.  Also on VMS systems, the four
   bin.'mach' directories created by rtar under [mfilters.bin] can be
   deleted.  UNIX sites should leave the symbolic link 'bin' in the MFILTERS
   root directory pointing to 'bin.generic' but can delete any of the 
   bin.`mach' directories that won't be used.  The archive file can be
   deleted once the package has been successfully installed.

[5] When the archive has been unpacked, build the MFILTERS package executable.  
    The compilation and linking of the MFILTERS package is done using the
    following command:

	cl> mkpkg -p mfilters update >& mfilters.spool &

    NOTE: On systems that concurrently support different architectures
    (e.g., Suns, Convex), you must configure the system for the desired
    architecture before issuing the above command.  SUN/IRAF sites must
    execute a pair of 'mkpkg' commands for each supported architecture type.
    The Unix environment variable IRAFARCH must be set as well before
    compiling.  For example:

	# Assuming IRAFARCH is set to ffpa
	cl> mkpkg -p mfilters ffpa
	cl> mkpkg -p mfilters update >& mfilters.ffpa &
	cl> mkpkg -p mfilters f68881
	# Now reset IRAFARCH to f68881 before continuing
	cl> mkpkg -p mfilters update >& mfilters.f68881 &

    The spool file(s) should be reviewed upon completion to make sure there
    were no errors.  

