jpegqs(1)

📦 version 1.20210408, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

🎀 NAME 🎀

jpegqs — JPEG Quant Smooth — it's giving JPEG artifacts removal, and honestly? iconic 💅✨

🦋 SYNOPSIS 🦋

jpegqs [options] input.jpg output.jpg

💖 DESCRIPTION 💖

okay so bestie, sit down, because this is actually so cool 🫶

This program tries to recover the lost precision of DCT coefficients based on a quantization table from a JPEG image. Like, it goes digging through the quant table and tries to put back what got squished out. 😭

The result is saved as a JPEG image with quantization set to 1 — which is the same energy as a JPEG saved at 100% quality. she's giving brand new, no cap 👑

✨ OPTIONS ✨

  • -q, --quality n — the quality setting, ranges from 0 to 6, and the default is 3 🌸
lowkey a lil mystery here — the original page has this path chillin' right at the end of this entry: /home/rainbow/Desktop/pngtest/jpegrestore/jpegqs.1 — so I'm keeping it because the rule is every detail stays, fr fr 🙈
  • -n, --niter n — number of iterations (default is 3) 🔁
    • More iterations can make the result look like CG art, can make the photos look unnatural. so like… she's giving render, not reality 😭
  • -t, --threads n — set the number of CPU threads to use 🧵 (yes she multithreads, we love a girlboss)
  • -o, --optimize — option for libjpeg to produce smaller output file 📦 (smaller file, same slay)
  • -v, --verbose n — print libjpeg debug output 🔊
  • -i, --info n — print quantsmooth debug output (default is 15) 📊

Use the sum of flags, so you literally add them up, it's math girlie hours:

  • 0 — silent 🤫
  • 1/2/4 — various information
  • 8 — processing time
  • 16 — SIMD type
⚠️ the processing time includes only the smoothing algorithm — jpeg reading and writing time is not included. don't get it twisted bestie 💀
  • -p, --cpu n — use to lower the SIMD type if CPU detection fails 🖥️
    • 0 — auto
    • 1 — scalar
    • 2 — SSE2
    • 3 — AVX2
    • 4 — AVX512
📌 x86 build selects between modes 1-3, x86_64 from 2-4. iykyk 🧚

🌈 QUALITY 🌈

The quality setting sets a combination of flags for processing, like a lil preset bundle, so cute 🎀

  1. default ⭐
  2. adds DIAGONALS flag
    • smoother diagonal edges, ~1.5 times slower. she's smoother but she's taking her time 💅
  3. adds JOINT_YUV flag
    • chroma channels will depend from luminance, better color consistency. the color girlies are gonna love this one 🎨
  4. adds UPSAMPLE_UV flag
    • non-blurring chroma upsampling, unlike fancy upsampling from libjpeg. no blur, only clarity ✨

levels 0-2 is the same as 4-6, but with LOW_QUALITY flag ~10 times faster, but the quality is lower 🏃‍♀️💨 LOW_QUALITY implies DIAGONALS (always set) — like, she said you're getting diagonals whether you asked or not 💀

🔥 PROJECT PAGE 🔥

https://github.com/ilyakurdyukov/jpeg-quantsmooth

go give it a star, bestie, it's free 🫶⭐

Copyright (C) 2016-2021 Ilya Kurdyukov

and that's the whole page, bestie!! this was JPEG Quant Smooth, version 08 Apr 2021, manual page jpegqs(1) — thank you for coming to my ted talk, mwah 💖🦋🌸✨

📦 where this page comes from