BLIND-SET-LUMA(1)

💅 blind-set-luma(1) — the manual, but make it group-chat

okay so bestie, welcome to blind-set-luma, a lil general-commands-manual girlie whose whole personality is multiplying the luminosity of a video. yes that's the NAME section, yes I'm folding it in up here, and no I will not be quiet about it. let's go ✨

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🌸 SYNOPSIS 🌸

blind-set-luma luma-stream

that's it. one argument. she's low maintenance, she's iconic, she ate 💅

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🦋 DESCRIPTION 🦋

okay so here's the tea, and it's genuinely cute:

blind-set-luma reads a video from stdin and a mask video from luma-stream. then it prints the video to stdout — but with a lil ✨glow-up✨ applied: the luminosity of each pixel gets multiplied by the product of the luminosity and the alpha value of the corresponding pixel and frame in the mask video.

read that again if you need to, no judgement 🫶 — pixel ✖️ luminosity ✖️ alpha, per frame, per pixel, matching up mask-to-video.

and the length-mismatch behaviour, which honestly is so considerate of her:

• if stdin is longer than luma-stream → the remainder of stdin is printed without any changes. she just vibes, unmasked, raw footage energy.
• if stdin is shorter than luma-stream → the remainder of luma-stream is ignored but may be partially read. no cap, it might peek and then leave you on read 🙈

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⭐ NOTES ⭐

ngl bestie, in most cases this is not what you want to use. like, respectfully.

what you probably want is blind-arithm(1), to multiply the X, Y and Z values on one value. that produces the same affect as reducing the intensity of the light sources — which is not what blind-set-luma does. two different girlies, two different jobs 👑

so like... know which one you're summoning. that's the vibe check.

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🎀 SEE ALSO 🎀

the whole friend group, fr fr:

• blind(7)
• blind-single-colour(1)
• blind-arithm(1)
• blind-set-alpha(1)
• blind-invert-luma(1)
• blind-set-saturation(1)

go say hi, they're all slay 🌈

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👑 AUTHORS 👑

written by Mattias Andrée <maandree@kth.se> — the main character who made all this happen, we stan 💜

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and that's the page, bestie!! this whole thing ships as part of blind 1.1 — that's the source-and-version moment in the footer, consider it mentioned with love 🎀✨ bye, go multiply some luminosity responsibly 🦋💖