FICONV(1)

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

🎀 FICONV(1) 🎀

okay bestie, welcome to the FICONV(1) page, straight out of the User Commands section 💅 this is ficonv, and she is that girl when it comes to convolution transformations. sit down, grab a strawberry, we're doing this together 🍓

✨ NAME ✨

ficonv — obtaining and evaluating convolution transformations 🦋

✨ SYNOPSIS ✨

ficonv [options] [-r <reference>] [-i <input>] [-o <output>]

✨ DESCRIPTION ✨

okay so this program has two whole jobs and honestly? iconic of her 💖

Job number one: take a reference FITS image and an input FITS image, and try to figure out the best-fit convolution kernel that transforms the reference image into the input image. The convolution kernel solution gets saved as a separate file — and ngl, it's a human-readable file, so you can literally open it and read it. slay.

Job number two: take an existing kernel solution file like that, and ficonv convolves the reference image with it, and optionally co-adds an additional image onto the result.

and how does she know which mood she's in? 😭 she figures out the desired mode (aka: are we fitting a convolution kernel, or are we using an existing kernel solution to convolve an image) from the presence or lack of the command line options. she just knows. main character energy fr fr 👑

✨ OPTIONS ✨

💅 General options:

  • -h, --help — gives you a general summary about the command line options. baby's first flag, we love her 🫶
  • --long-help, --help-long — gives you a detailed list of command line options. the long-form lore drop ✨
  • --wiki-help, --help-wiki, --mediawiki-help, --help-mediawiki — gives you a detailed list of command line options in Mediawiki format. wiki girlies rise 🌈
  • --version, --version-short, --short-version — gives you some version information about the program. identity check 💅
  • -r, --reference, --input-reference <image file> — the name of the reference FITS image file. your blueprint, your blueprint-bestie 🎀
  • -i, --input <image file> — the name of the input FITS image file. heads up though: this is required only for kernel fitting, so if you're not fitting, you can skip her 🙈
  • -k, --kernel, --kernels <kernel set> — the list of kernel bases used for fitting the convolution kernel. also: check out "Kernel specifications" below for the format of this <kernel set> argument, iykyk 🧚
  • --input-kernel-list <file> — the name of the file containing kernel bases. and here's the tea ☕ the kernel bases in this file should have no associated coefficients if convolution fitting is done — otherwise (i.e. if fitting is not done) the kernel basis file must contain the convolution coefficients.
  • --output-kernel-list <file> — the name of the file where the coefficients for the kernel bases are stored after convolution kernel fitting. receipts, but make them math 💖
  • -o, --output, --output-convolved <image file> — the name of the output file, which is the reference image convolved with the kernel solution. and that kernel solution can either be one that was previously fitted and is now being read from a file, or the result of the current fit. either way, she ate 🔥
  • --output-subtracted <image file> — the difference between the input image and the convolved reference image. the ✨delta✨ the gap the character development 😭
  • -a, --add-to <image file> — this optionally specified file is added to the convolved image. optional queen 💜
  • -M, --input-mask <fits> — input mask file, to co-add to the output image mask. masks ON, bestie 🎭
  • -n, --iterations <iterations> — use an iterative fit, with the rejection of the outlier pixels 👋 bye outliers. the maximum number of iterations should be specified with this command line argument, so tell her how many rounds you're down for.
  • -s, --rejection-level <sigma> — the rejection level, in standard deviation units. sigma behavior, literally 📏

🧚 Kernel specifications (each separated with a semi-colon, ;) 🧚

(quick heads-up: the original page formats this heading as Kernel specifications (each separated with a semi-colon, ;")":" — we're keeping the chaos, we're just not repeating it 💀)

so each kernel spec is separated with a semi-colon, ;. here are the flavors 🌈:

  • i/<spatial order> — identity kernel, a.k.a. the "flux term", with the specified order of polynomial spatial variations. no cap, that's the name 💅
  • b/<spatial order> — constant offset kernel, a.k.a. the "background term", with the specified order of polynomial spatial variations. she's giving vibes in the back 🌸
  • d=<size>/<spatial order> — discrete kernel, with the half-size of <size> and the specified order of polynomial spatial variations. discrete but make it detailed ✨
  • g=<size>,<sigma>,<order>/<spatial order> — Gaussian kernel, with the half-size of <size>, standard deviation of <sigma>, and Hermite basis order of <order>, with the specified order of polynomial spatial variations. Gaussian girlie with a Hermite twist, we're obsessed 😌

✨ REPORTING BUGS ✨

found a bug? 😭 don't suffer in silence, bestie — report bugs to <apal@szofi.net>, and also peep https://fitsh.net/. 🐛➡️📮

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

aaaand that's the whole page, bestie 🫶 this was ficonv 0.9.4 (2021.01.24), from January 2021, and yes the vibes were immaculate the entire time. now go convolve something. periodt 💅⭐

📦 where this page comes from