CONVOLVE(1)

📦
version 0.24 · 5 versions
, in epel 10, epel 9, nixos 26.05, nixpkgs unstable, ubuntu resolute, ubuntu stonking

💖 CONVOLVE(1) — the astconvolve glow-up 💖

okay so bestie, welcome to the Convolve page from GNU Astronomy Utilities 0.24, filed under User Commands 🎀 and it's literally about smooshing an image with a kernel. iconic behaviour, honestly.

✨ NAME ✨

Convolve — convolve an image with a given kernel 🫶

🌸 SYNOPSIS 🌸

astconvolve [OPTION...] ASTRdata

🦋 DESCRIPTION 🦋

Convolve is part of GNU Astronomy Utilities 0.24. She will convolve an input image with a given spatial kernel (image) — either in the spatial domain (no edge effects, queen behaviour 💅) or in the frequency domain. And ngl, the frequency domain one does suffer from edge effects, but it can be much faster. trade-offs, we love to see it ✨

For more info, bestie, just run any of these. The second one especially is the comprehensive lore drop on how to invoke Convolve: what inputs it expects, what outputs it gives, and a full rundown of every single option. 👑

All options and their values:

$ astconvolve -P

Inputs/Outputs and options:

$ info astconvolve

Full section in manual/book:

$ info Convolve

Full Gnuastro manual/book:

$ info gnuastro

If you couldn't find your answer in the manual, you can get direct help from experienced Gnuastro users and developers. For more information, please run:

$ info help-gnuastro

💜 Convolve options 💜

🍓 Input 🍓

  • -c, --column=STR — column name or number if the input is a table.
  • -h, --hdu=STR/INT — extension name or number of the input data.
  • -H, --minsharpspec=FLT — deconvolution: minimum spectrum of the sharp image.
  • --kernelcolumn=STR — column name or number if the kernel is a table.
  • -k, --kernel=FITS — file name of the kernel you're convolving with.
  • --nokernelflip — do not flip the kernel image.
  • --nokernelnorm — do not normalize the kernel image.
  • --searchin=STR — pick the column(s): 'name', 'unit', 'comment'.
  • --stdintimeout=INT — micro-seconds to wait for standard input.
  • -u, --khdu=STR — HDU containing the kernel.

🧚 Tessellation (tile grid) 🧚

  • --checktiles — tile IDs in an image, the size of the input.
  • -F, --remainderfrac=FLT — fraction of remainder to split the last tile.
  • --interpmetric=STR — interpolation metric (radial, manhattan).
  • -M, --numchannels=INT[,..] — no. of channels in dim.s (FITS order).
  • --oneelempertile — display 1 element/tile, not full input resolution.
  • --workoverch — work (not tile) over channel edges.
  • -Z, --tilesize=INT[,INT] — regular tile size on dim.s (FITS order).

🌈 Output 🌈

  • --conv-on-blank — do convolution on blank pixels also.
  • -C, --checkfreqsteps — view the steps in the frequency domain.
  • -D, --dontdelete — don't delete the output if it exists.
  • -K, --keepinputdir — keep the input directory for automatic output.
  • --noedgecorrection — do not correct the edges in the spatial domain.
  • --outfitsnocommit — no Git commit in the 0-th HDU of the output FITS.
  • --outfitsnoconfig — no metadata in the 0-th HDU of the output FITS.
  • --outfitsnodate — no 'DATE' in the 0-th HDU of the output FITS.
  • --outfitsnoversions — no versions in the 0-th HDU of the output FITS.
  • -o, --output=STR — output file name.
  • --tableformat=STR — table fmt: 'fits-ascii', 'fits-binary', 'txt'.
  • -T, --type=STR — type of output: e.g., int16, float32, etc...
  • --wcslinearmatrix=STR — WCS linear matrix of output ('pc' or 'cd').

👑 Operating modes 👑

  • -?, --help — give this help list.
  • --checkconfig — list all config files and variables read.
  • --cite — BibTeX citation for this program.
  • --config=STR — read configuration file STR immediately.
  • --config-prefix=STR — custom prefix of option names in config files.
  • -d, --domain=STR — convolution domain: 'spatial', 'frequency'.
  • --lastconfig — do not parse any more configuration files.
  • --minmapsize=INT — min. bytes to avoid RAM automatically.
  • -m, --makekernel=INT — make a 2*INT kernel to create the input image.
  • -N, --numthreads=INT — number of CPU threads to use.
  • --onlyversion=STR — only run if the program version is STR.
  • -P, --printparams — print parameter values to be used and abort.
  • --quietmmap — don't print mmap'd file's name and size.
  • -q, --quiet — only report errors, remain quiet about steps.
  • -S, --setdirconf — set default values for this directory and abort.
  • --usage — give a short usage message.
  • -U, --setusrconf — set default values for this user and abort.
  • -V, --version — print program version.
📌 Mandatory or optional arguments to long options are also mandatory or optional for any corresponding short options. no cap, that's just how it works bestie 💅

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

😭 REPORTING BUGS 😭

Report bugs to bug-gnuastro@gnu.org. (they're nice, fr fr, don't be shy 🫶)

Copyright © 2015-2025 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. 🫣

Written/developed by Mohammad Akhlaghi 👑

🌟 SEE ALSO 🌟

The full documentation for Convolve is maintained as a Texinfo manual. If the info and Convolve programs are properly installed at your site, the command

info Convolve

should give you access to the complete manual. go read it, it's giving main character energy 📚✨

okay bye bestie, that was GNU Astronomy Utilities 0.24 from November 2025 — this has been your girl CONVOLVE(1), convolving images and hearts since forever 💖🎀🦋✨

📦 where this page comes from