UNU-HEQ(1)

💖 UNU-HEQ(1) — the unu heq glow-up page 💖

okay so bestie, welcome to unu-heq, a lil member of the unu user-commands family, and she is here to perform histogram equalization. that's it, that's the job. iconic behaviour, honestly. ✨

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🌸 NAME 🌸

unu-heq — perform histogram equalization 💅

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🎀 SYNOPSIS 🎀

unu heq -b,--bin <bins> [-s,--smart [<bins>]] [-a,--amount <amount>]
[-m,--map <filename>] [-i,--input <nin>] [-o,--output <nout>]

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🦋 DESCRIPTION 🦋

So you wanna perform histogram equalization. slay. 🫶

But listen — if it seems like this is doing literally nothing, do not panic, do not spiral. try increasing the number of histogram bins by an order of magnitude or two (or more, she's not gonna stop you 👑). Or, alternatively, go use unu-gamma(1) to warp the values in the direction you know they need to go. Either of these might work because — and this is the tea — extremely tall and narrow peaks in the equalization histogram will produce poor results. 😭 so narrow. so peak. so unhelpful.

• Uses nrrdHistoEq

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✨ OPTIONS ✨

• -b <bins>, --bin <bins> — the number of bins to use in the histogram that gets created in order to calculate the mapping that achieves the equalization. (int) 🍓
• -s [<bins>], --smart [<bins>] — number of bins in the value histogram to ignore when calculating the mapping. Bins get ignored when they rack up more hits than other bins, and also when the values that fall in them are constant. This is, like, a genuinely effective way to stop huge regions of background value from distorting the equalization mapping. (optional int); default: “0” 💜
• -a <amount>, --amount <amount> — the extent to which the histogram equalizing mapping should be applied. 0.0 means no change, 1.0 means full equalization (float); default:

⚠️ okay bestie, the page itself gets a lil scrambled right here. this is verbatim what it says, no cap: -t <type> , --type <type> output type; default: “1.0”

so yeah — -t <type>, --type <type> is an output type, and the default is “1.0”. that's the whole thing as printed, we don't make the rules 🙈

• -m <filename>, --map <filename> — the value mapping used to achieve histogram equalization is represented by a univariate regular map. Give a filename here and that map gets saved out, so you can apply it to other nrrds with unu-rmap(1) (string) 🔥
• -i <nin>, --input <nin> — input nrrd 🌈
• -o <nout>, --output <nout> — output nrrd (string); default: “-” ⭐

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👑 SEE ALSO 👑

unu(1), unu-gamma(1), unu-rmap(1)

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and that's the whole page, bestie!! 🧚 source/version + date tea: this one's from the User Commands manual, dated August 2021. go forth and equalize those histograms, main character. 💖🌸✨