NAME

       mSubimage - Create a "cutout" of a FITS image

SYNOPSIS

       mSubimage [-d] [-a] [-h hdu] [-s statusfile] in.fits out.fits ra dec xsize [ysize]

       mSubimage  -p  [-d] [-h hdu] [-s statusfile] in.fits out.fits xstartpix ystartpix xpixsize
       [ypixsize]

DESCRIPTION

       Creates a subimage (or "cutout") of a FITS file.  Note that in "normal" mode,
             all the parameters (location and size) are in degrees; in pixel (-p) mode, all of
             them are in pixels

OPTIONS

       -d     Turns on debugging.

       -a     All pixels - Force retrieval of whole image (useful to extract an entire HDU)

       -h hdu Operate on the specified FITS header extension (HDU)

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

       -p     Pixel mode - create subimage using pixel locations, instead of a  location  on  the
              sky

ARGUMENTS

       in.fits
              Input FITS file.

       out.fits
              Path to output FITS file.

       ra     In normal mode, RA of center of output image.

       dec    In normal mode, declination of center of output image.

       xstartpix
              In pixel mode, pixel along the x-axis where the cutout image will begin

       ystartpix
              In pixel mode, pixel along the y-axis where the cutout image will begin

       xsize  In normal mode, width of output image in degrees.

       ysize  In normal mode, height of output image in degrees (default is equal to xsize.

       xpixsize
              In pixel mode, width of output image in pixels

       ypixsize
              In pixel mode, height of output image in pixels (default is equal to xpixsize

RESULT

       [struct stat="OK", content="blank, flat or normal"]

       The  content  keyword  indicates whether all pixels where NaN (blank), all pixels were the
       same value (flat), or the image appears to be normal.

MESSAGES

       OK     [struct stat="OK", content="blank, flat or normal"]

       ERROR  HDU value (hdu) must be a non-negative integer

       ERROR  Cannot open status file: statusfile

       ERROR  Center RA string (string) cannot be interpreted as a real number

       ERROR  Center Dec string (string) cannot be interpreted as a real number

       ERROR  X size string (string) cannot be interpreted as a real number

       ERROR  Y size string (string) cannot be interpreted as a real number

       ERROR  Invalid 'x' size

       ERROR  Invalid 'y' size

       ERROR  Image file filename missing or invalid FITS

       ERROR  Cannot find HDU hdu

       ERROR  Output wcsinit() failed.

       ERROR  Location is off image

       ERROR  Region outside image

       ERROR  No pixels match area.

       ERROR  Can't create output file: out.fits

       ERROR  FITS library error

EXAMPLES

       $ mSubimage image1.fits subimage.fits 307.9 37.29 .01 .01
              [struct stat="OK", content="normal"]

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.