ficombine1

Combining (most frequently, averaging) a set of images

Usage

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

Overview

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.

History

Debian 13 (Trixie) to Debian 11 (Bullseye): the text shown here
Debian 10 (Buster) to Debian 9 (Stretch)

--history since Debian 11 (Bullseye); --no-history since Debian 11 (Bullseye).