FIINFO(1)

💖 FIINFO — bestie edition 💖

okay so real talk, this is the manpage for fiinfo, and it's genuinely iconic. it lives in the User Commands section of the manual (section 1, for the nerds keeping score 📖) and it's here to tell you literally everything about how to pull info and image stamps out of images. stay with me, it's giving useful.

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🌸 NAME 🌸

fiinfo — providing information or image stamps for images ✨

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🎀 SYNOPSIS 🎀

fiinfo [options] [-i <input>] <outputs>

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🦋 DESCRIPTION 🦋

so the whole main character purpose of the fiinfo program is to give you some information about your FITS files. primarily that's FITS images, but ngl, output dump is supported for tables and binary tables also. it's versatile, it's talented, it ate 💅

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✨ OPTIONS ✨

💜 General options

• -h, --help — gives you a general summary about the command line options. quick lil vibe check of what's available.
• --long-help, --help-long — gives you a detailed list of command line options. the full tea ☕
• --wiki-help, --help-wiki, --mediawiki-help, --help-mediawiki — gives you a detailed list of command line options but in Mediawiki format. for when you need it wiki-fied.
• --version, --version-short, --short-version — gives some version information about the program. who are you, really? 🪞
• -i, --input <image file> — name of the input FITS image file. your source material bestie.
• --summary, --long-summary — give a summary about the content structure of the FITS file. namely, the main characteristics and dimensions of the primary image, followed by the list of optional extensions and their main properties. it's like a little recap episode of your FITS file 🗂️
• -s, --statistics <list of statistics> — calculate basic statistics for the image. see "Statistics options" below for available statistics methods. the statistics itself contains four numbers: the total number of pixels involved in the calculations, the final number of pixels used for the statistics (which might be smaller than the previous one if the outliers are rejected), an average value and a scatter. four numbers, no cap 📊
• -d, --data <list of derived image data> — calculate some other more quantities related to astronomical images. this option should be followed by a comma-separated list of quantities. see "Image characteristics" below for more details about these.
• -b, --box <number of blocks> — this option specifies the number of blocks, which is used to divide the input image. some quantities (see "Image characteristics") can be derived on a per block basis either. chop chop 🔪
• -a, --order <order> — order of polynomial spatial variations in some derived image characterization quantities (see also "Image characteristics"). math girlies rise 🧮
• -n, --newline — in the output, each quantity should be written in separate lines. by default, the output is a single line, containing the desired quantities or statistics. one line is the default vibe, but you can ✨spread out✨
• --ignore-mask — completely ignore the mask associated to the input image. mask? never heard of her 🙈
• --output-dump <file> — name of an output file in which a raw image dump is written. each line of this file contains 3 or 4 columns: X, Y coordinates and flux, optionally followed by the associated mask flag (see also "-m|--dump-mask").
• -m, --dump-mask — the raw image dump specified by "--output-dump" should contain the masking information beyond the coordinates and intensities.
• --output-pnm, --output-ppm, --output-pgm — name of an output file in which the image is stored in a variant of PNM format. these images are intended to be a kind of "human visible" images, appropriately scaled for normal displays. these images are stored in PNM format, which is an easily parseable (thus raw, uncompressed) format, supported by many graphic programs (and by the NETPBM package). such an image conversation always results data loss. see also options "--pgm" or "--ppm" for further details.

⚠️ real talk: that conversion always results in data loss. it's a glow-up for your eyeballs, not for your data. the original is prettier, sorry 💀

• --pgm <PGM specific conversion options> — this command line argument is followed by a comma-separated list of options, which specifies the scaling and other properties of the output image. the resulted image will be a grey-scale (PGM) image, even if a color palette is requested. see "PNM specifications" below.
• --ppm <PPM specific conversion options> — this command line argument is followed by a comma-separated list of options, which specifies the scaling and other properties of the output image. the resulted image will be a true-color (PPM) image, even if a greyscale colormap is requested. see also "PNM specifications" below for more details.

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🌈 Statistics options

• mean — the mean value of the pixel intensities.
• median — the median value of the pixel intensities.
• iterations — reject the outlier pixels before doing any statistics. bye outliers, we don't know them 👋
• lower=<sigma>, upper=<sigma>, sigma=<sigma> — lower, upper or common rejection level, in the units of standard deviation (which is derived around the mean or median value, depending on the request of the user).

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⭐ Image characteristics

• min, max — minimal and maximal pixel intensities on the image.
• mean — mean intensity level.
• stddev — standard deviation.
• sky — sky background level.
• skysigma — sky background scatter.

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🧚 PNM specifications

• linear — use a linear intensity scaling.
• log — use a logarithmic intensity scaling.
• squared — use a squared intensity scaling.
• sqrt — use a square root intensity scaling.
• histequ — use a histogram equalized intensity scaling.
• minmax — use the minimal and maximal pixel intensities for scaling boundaries.
• percentage=<%> — use the minimal and maximal values of the innermost specified percent of the pixel intensities.
• min=<min>, max=<max> — use the specified minimal and maximal values for scaling boundaries.
• zscale — use the "zscale" algorithm to determine scaling boundaries.
• zmax, zmin — use the "zmax" or "zmin" algorithm to determine scaling boundaries.
• zcontrast=<zcontrast> — use the specified contrast value to determine the scaling boundaries in the case of "zscale", "zmax" or "zmin" methods. the default value is 0.25.
• reverse — use an inverted color map. flip it 🔄
• contrast=<C>, brightness=<B> — use the specified values for adjusting the final contrast and brightness. the default values are 1 and 0.5, respectively, according to the standard image contrast and brightness level definitions.
• 8, 8bit — create an 8-bit PGM or PPM output. this is the default.
• 16, 16bit — create a 16-bit PGM or PPM output instead of the default 8-bit.
• palette=<color1>:<color2>:<color3>:... — specify an alternate color map. each color should be a hexadecimal representation of a given color, i.e. it should be in one of the forms of G, GG, GGGG, RGB, RRGGBB or RRRRGGGGBBBB, denoting 4 bit grey, 8 bit grey, 16 bit grey, 3x4 bit truecolor, 3x8 bit truecolor or 3x16 bit truecolor representation, respectively. the color map gradient will be continuous if the colors are separated by colons. jumps in the gradient can be defined by separating the successive colors by a slash, "/" instead of colons. 🎨 this is where you get to be the artist fr fr

📌 note that the syntax followed by the "--pgm" or "--ppm" command line arguments is exactly the same for both options. however, color images will be converted to greyscale if "--pgm" is specified, and vice versa, "--ppm" always yields a PPM format, even if the color gradient is merely a grayscale one. the default palette is 0:F for both PGM and PPM formats, i.e. a pure black - white gradient. 🖤🤍

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🫶 REPORTING BUGS 🫶

found a bug? report bugs to <apal@szofi.net>, see also https://fitsh.net/. don't be shy, they want to know 💌

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👑 COPYRIGHT 👑

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

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and that's the whole thing bestie, you're officially fluent 💖 this was fiinfo version 0.9.4 (dated 2021.01.24), from January 2021 — the manual page itself is FIINFO(1) and yes she's iconic, no notes 🌟