NAME

       ficombine - combining (most frequently, averaging) a set of images

SYNOPSIS

       ficombine [options] <input images> [-o|--output <output>]

DESCRIPTION

       The  purpose  of  this  program  is to combine the input images (with the same sizes) to a
       single image. This combination refers to a kind of "averaging" for  the  images,  however,
       other modes are also available.

OPTIONS

   General options:
       -h, --help
              Gives general summary about the command line options.

       --long-help, --help-long
              Gives a detailed list of command line options.

       --wiki-help, --help-wiki, --mediawiki-help, --help-mediawiki
              Gives a detailed list of command line options in Mediawiki format.

       --version, --version-short, --short-version
              Gives some version information about the program.

       -o, --output <fits>
              The  name  of  the  output  file (omitting or specifing '-' yields the output to be
              written to stdout).

       --history, --no-history
              Incude or exclude the command line of the invoking `ficombine`  call.  By  default,
              the  command  line  is  added  into  the  FITS  headers (FI_HSTRY) but if there are
              enormous amount of input files, one can use --no-history  to  omit  the  respective
              lengthy keywords.

       --data <spec>
              Output pixel data format specification.

       -b, --bitpix <bitpix>
              Standard FITS output bitpix value.

       -M, --input-mask <fits>
              Input mask file to co-add to output image.

   Generic combination specification:
       -m, --mode <mode>
              Use the specified mode to combine images.

       -n, --ignore-negative
              Ignore (i.e. mask) pixels with negative values.

       --logical-or
              Use logical "or" combination between masks.

       --logical-and
              Use logical "and" combination between masks.

   Combination modes (a comma-separated list of these should follow -m|--mode):
       mean   The mean value of the pixels.

       median The median value of the pixels.

       min, minimum
              The minimum value of the pixels.

       max, maximum
              The maximum value of the pixels.

       rejmed, rejection
              Median value after rejecting outliers.

       rejmean
              Mean value after rejecting outliers.

       iterations=<n>
              Number of iterations to reject outliers.

       lower=<l>, upper=<u>, sigma=<s>
              Outlier  limit  (lower, upper, both) in standard deviation. Note that setting sigma
              to some value is equivalent to setting  'lower'  and  'upper'  to  the  same  value
              simultaneously.

       truncated
              Truncated mean.

       winsorized
              Winsorized mean.

       lowest=<cnt>, highest=<cnt>, discard=<cnt>
              Reject  the  'lowest'  and  'highest'  count  of points when computing truncated or
              winsorized mean. Setting 'discard' to some value is equivalent to setting  'lowest'
              and 'highest' to this value simultaneously.

       sum    Sum of the pixel values.

       squaresum
              Sum for the squarers of the pixel values.

       scatter, stddev
              Pixel scatter (standard deviation).

       or     Use logical "or" combination between masks.

       and    Use logical "and" combination between masks.

       ignorenegative
              Ignore (i.e. mask) pixels with negative values.

       ignorezero
              Ignore (i.e. mask) pixels with a zero value.

       ignorenegative
              Ignore (i.e. mask) pixels with positive values.

REPORTING BUGS

       Report bugs to <apal@szofi.net>, see also https://fitsh.net/.

COPYRIGHT

       Copyright © 1996, 2002, 2004-2008, 2010-2016, 2018-2020; Pal, Andras <apal@szofi.net>