mFlattenExec - Remove the background from an image

       images.tbl
              Metadata table (generated by mImgtbl) describing images to be flattened.

       flatdir
              Path to directory where output files should be created.

       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.

       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.

Montage 5                                           Dec 2016                                     MFLATTENEXEC(1)

       Runs both mFitPlane and mBackground on a set of images.

       $ mFlattenExec output/images.tbl output/flattened
              [struct stat="OK", count=5, failed=0, warning=0]

       OK     [struct stat="OK", count=nimages, failed=nfailed, warning=nwarnings]

       ERROR  Cannot open status file: statusfile

       ERROR  Cannot access flatdir

       ERROR  flatdir is not a directory

       ERROR  Invalid image metadata file: filename

       ERROR  Need column 'file' in image metadata file filename

       ERROR  mDifformBackgrounderror

       mFlattenExec - Remove the background from an image

       -p imgdir
              Specifies path to directory containing images to be flattened.

       -d     Turns on debugging.

       -n     No-area-images flag, indicating that mFlattenExec should not require area images for all the input
              FITS images.

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

       Creates "flattened" versions of each input FITS image.

       mFlattenExec [-p imgdir] [-d] [-n(o-areas)] [-s statusfile] images.tbl flatdir