FICOMBINE(1)

📦 version 0.9.4, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

💖 FICOMBINE(1) 💖

okay bestie, sit DOWN, because today we're talking about ficombine — the User Commands girlie who takes a whole squad of images and merges them into one. 🫶

✨ NAME ✨

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

🎀 SYNOPSIS 🎀

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

🦋 DESCRIPTION 🦋

so the whole point of this program, bestie, is to take your input images — which all gotta have the same sizes, no cap — and combine them into a single image. 🌈

and when we say "combine"? we're mostly talking about a kind of "averaging" for the images. that's the main character energy here. BUT — and this is the fun part — other modes are also available. she's versatile like that. ✨

💅 OPTIONS 💅

🌸 General options: 🌸

  • -h, --help — gives you a general summary about the command line options. quick lil vibe check on the flags.
  • --long-help, --help-long — gives a detailed list of command line options. the deluxe version, the director's cut, the extended edition. 👑
  • --wiki-help, --help-wiki, --mediawiki-help, --help-mediawiki — gives that same detailed list of command line options, but in Mediawiki format. wiki girlies, this one's for you. 💜
  • --version, --version-short, --short-version — gives some version information about the program. identity reveal moment. 🪪
  • -o, --output <fits> — the name of the output file. if you omit it, or specify -, the output gets written to stdout. yes, literally the dash. iconic behaviour tbh. 🍓
  • --history, --no-history — include 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 you've got an enormous amount of input files, you can use --no-history to omit the respective lengthy keywords. she's keeping receipts by default, but you can ask her to stop journaling. 📓
  • --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 the output image. 🎭

🧚 Generic combination specification: 🧚

  • -m, --mode <mode> — use the specified mode to combine images. pick your fighter. ⚔️
  • -n, --ignore-negative — ignore (i.e. mask) pixels with negative values. bye negative pixels, we don't know her. 🙈
  • --logical-or — use logical "or" combination between masks.
  • --logical-and — use logical "and" combination between masks.

🔥 Combination modes 🔥

so here's the tea: a comma-separated list of these should follow -m|--mode. mix and match, bestie.

  • 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. the "not you, not you, and definitely not you" mode. 💀
  • 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. and heads up: setting sigma to some value is equivalent to setting lower and upper to the same value simultaneously. two birds, one flag. 🐦
  • 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. and just like the sigma thing: 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.
bestie I am NOT playing around: the original page literally lists ignorenegative twice, once with "negative values" and once with "positive values". I'm keeping it exactly as written because the vibe changes but the facts do NOT. 👑💅

😭 REPORTING BUGS 😭

found a bug? report it to <apal@szofi.net> — and see also https://fitsh.net/. 🫶

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

and that's the whole page, bestie!! 🌟 this one's ficombine 0.9.4 (2021.01.24), dated January 2021, and it's giving FICOMBINE(1) through and through. now go average some images. slay. 💖✨🦋

📦 where this page comes from