ASTSCRIPT-COLOR-FAINT-GRAY(1)

📦 version 0.24, in epel 10, epel 9, nixos 26.05, nixpkgs unstable, ubuntu resolute, ubuntu stonking

✨ astscript-color-faint-gray ✨

okay bestie, welcome to ASTSCRIPT-COLOR-FAINT-GRAY(1) — a User Commands moment, literally iconic. this is the page for astscript-color-faint-gray and she's about to make your FITS files look absolutely stunning. no cap. 💅

NAME 💖

astscript-color-faint-gray — RGB image from FITS images showing bright and faint features

like. she takes your FITS pics and gives you a color image where you can see BOTH the bright stuff AND the faint stuff. it's giving main character energy fr fr. 🌈

SYNOPSIS 🦋

astscript-color-faint-gray [OPTION] R.fits G.fits B.fits K.fits

four FITS files in, one gorgeous color image out. slay. ✨

DESCRIPTION 🌸

bestie, listen. this script is part of GNU Astronomy Utilities 0.24. 🎀

so what she does: she generates a color image from three different images (RGB). and the way she shows the entire range of pixel values? an asinh transformation, periodt. if you wanna read more about the definition of this algorithm, go look at Lupton et al. 2004:

https://doi.org/10.1086/382245

(go off, Lupton et al. 👑)

for more info, please run any of the following commands. and like, especially the first one — it has a very comprehensive explanation of this script's invocation: expected input(s), output(s), and a full description of all the options. iykyk. 🫶

Inputs/Outputs and options:

$ info astscript-color-faint-gray

Full Gnuastro manual/book:

$ info gnuastro

and if you couldn't find your answer in the manual, don't stress 💜 — you can get direct help from experienced Gnuastro users and developers. for more information, please run:

$ info help-gnuastro

astscript-color-faint-gray options: 🧚

Input: 🍓

  • -h, --hdu=STR — HDU/extension for the input channels. tell her where your data lives.
  • -r, --reghdu=STR — HDU/extension for the regions image.
  • -g, --globalhdu=STR/INT — use this HDU for all inputs, ignore --hdu. one HDU to rule them all fr.
  • -w, --weight=FLT — relative weight for each input channel.
  • -m, --minimum=FLT — minimum value for each input channel.
  • -z, --zeropoint=FLT — zero point magnitude of each input channel.

Asinh scaling parameters 🌟

  • -Q, --qbright=FLT — parameter for bringing out brighter features. the bright girlies get their moment. ✨
  • -s, --stretch=FLT — linear stretching parameter for faint features. and the shy faint ones get theirs too. 🥺

Contrast, bias, and marks 🎀

  • -b, --bias — constant (bias) to add to all the pixels (linear).
  • -c, --contrast — change the contrast of the final image (linear).
  • -G, --gamma — gamma (nonlinear, overrides bias/contrast). yes bestie she overrides them, no discussion. 💀
  • --markoptions=STR — options to add marks (passed to ConvertType).

Color and gray parameters 💅

  • --coloronly — no grayscale regions, background in color (black).
  • --regions=STR — regions labeled image (color=2, black=1, gray=0).
  • --grayval=FLT — gray threshold (highest value to use grayscale).
  • --colorval=FLT — color threshold (lowest value to have color).
  • --graykernelfwhm=FLT — kernel FWHM for convolving the background image.
  • --colorkernelfwhm=FLT — kernel FWHM for color separation ref. image.

Output: 🌈

  • -k, --keeptmp — keep temporary/auxiliar files. (she keeps the receipts 👀)
  • -o, --output — output color image name.
  • --checkparams — print distribution of values used to find params.

Operating mode: 🦋

  • -h, --help — print this help list.
  • -q, --quiet — don't print the list.
  • -V, --version — print program version.
  • --cite — BibTeX citation for this program.

mandatory or optional arguments to long options are also mandatory or optional for any corresponding short options. (yes, the same rules apply both ways, she's consistent like that 💖)

GNU Astronomy Utilities home page: http://www.gnu.org/software/gnuastro/

REPORTING BUGS 🐛

found a bug? no stress, report bugs to bug-gnuastro@gnu.org. they're nice, i promise. 🫶

Copyright © 2021-2025, Free Software Foundation, Inc. License GPLv3+: GNU General public license version 3 or later.

This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. (like, none at all bestie, read it and weep 😭)

Written/developed by Raul Infante-Sainz and Mohammad Akhlaghi. kings. absolute icons. 💜

SEE ALSO 🌸

the full documentation for astscript-color-faint-gray is maintained as a Texinfo manual. if the info and astscript-color-faint-gray programs are properly installed at your site, the command

info astscript-color-faint-gray

should give you access to the complete manual. go read it, it's a whole vibe. 📖✨

and that's the whole page, bestie!! this was GNU Astronomy Utilities 0.24, dated November 2025, and i'm obsessed with her. now go make some beautiful color images and remember: bright features, faint features, all of them get to shine. periodt. 💅🎀💖

📦 where this page comes from