NAME

       mShrink - Re-size a FITS image

SYNOPSIS

       mShrink [-f] [-d level] [-h hdu] [-s statusfile] in.fits out.fits factor

DESCRIPTION

       A utility for reducing the size of a FITS file, by averaging blocks of pixels.

OPTIONS

       -f     Fixed-size  flag  -  specify  output  size of image, instead of the size of blocks of pixels to be
              averaged

       -d level
              Turns on debugging to the specified level (1-4).

       -s statusfile
              Output and errors are sent to statusfile instead of to stdout

ARGUMENTS

       in.fits
              Input FITS file

       out.fits
              Path to output FITS file.

       -h hdu Use the specified FITS extension (default is to use the first HDU with image data)

       factor Size of blocks, in pixels, to average. File size will be reduced by 1/factor squared.  If  the  -f
              (fixed-size) flag is used, factor is the desired width of the output image.

RESULT

       [Normal mode]: FITS output image, reduced in size by a factor of (1/factor)^2  .

       [Fixed-size mode]: FITS output image of width factor

MESSAGES

       OK     [struct stat="OK"]

       ERROR  Cannot open status file: statusfile

       ERROR  Image size factor cannot be interpreted as an real number

       ERROR  Shrink factor factor cannot be interpreted as an real number

       ERROR  [struct stat="ERROR", msg=

       ERROR  Image file in.fits missing of inavlid FITS.

       ERROR  FITS library error

EXAMPLES

       $ mShrink final/out.fits final/out-lowres_5.fits 5
              [struct stat="OK"]

BUGS

       The drizzle algorithm has been implemented but has not been tested in this release.

       If a header template contains carriage returns (i.e., created/modified on a Windows machine), the cfitsio
       library will be unable to read it properly, resulting in the  error:  [struct  stat="ERROR",  status=207,
       msg="illegal character in keyword"]

       It  is  best  for  the  background  correction  algorithms  if  the area described in the header template
       completely encloses all of the input images in their entirety. If parts of input images are "chopped off"
       by  the  header  template,  the  background correction will be affected. We recommend you use an expanded
       header for the reprojection and background modeling steps, returning to  the  originally  desired  header
       size  for  the  final  coaddition.  The  default background matching assumes that there are no non-linear
       background variations in the individual images (and therefore in the overlap differences).  If  there  is
       any  uncertainty  in  this  regard, it is safer to turn on the "level only" background matching (the "-l"
       flag in mBgModel.

COPYRIGHT

       2001-2015 California Institute of Technology, Pasadena, California

       If your research uses Montage, please include the following acknowledgement: "This research made  use  of
       Montage.  It  is  funded  by  the  National  Science  Foundation  under Grant Number ACI-1440620, and was
       previously funded by the National Aeronautics and Space Administration's Earth Science Technology Office,
       Computation  Technologies  Project,  under  Cooperative  Agreement  Number  NCC5-626 between NASA and the
       California Institute of Technology."

       The Montage distribution includes an adaptation of the MOPEX algorithm developed at the  Spitzer  Science
       Center.