jpegqs(1)

JPEG artifacts removal

Section 1 jpegqs bookworm source

Description

jpegqs

NAME

JPEG Quant Smooth - JPEG artifacts removal

DESCRIPTION

This program tries to recover the lost precision of DCT coefficients based on a quantization table from a JPEG image. The result is saved as a JPEG image with quantization set to 1 (like a JPEG saved at 100% quality).

SYNOPSIS

jpegqs [options] input.jpg output.jpg

OPTIONS

-q, --quality n

Quality setting (0-6, default is 3)/home/rainbow/Desktop/pngtest/jpegrestore/jpegqs.1

-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.

-t, --threads n

Set the number of CPU threads to use

-o, --optimize

Option for libjpeg to produce smaller output file

-v, --verbose n

Print libjpeg debug output

-i, --info n

Print quantsmooth debug output (default is 15).
Use the sum of flags:

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.

-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

QUALITY

The quality setting sets a combination of flags for processing:
3. default
4. adds DIAGONALS flag

smoother diagonal edges, ˜1.5 times slower

5. adds JOINT_YUV flag

chroma channels will depend from luminance, better color consistency

6. adds UPSAMPLE_UV flag

non-blurring chroma upsampling, unlike fancy upsampling from libjpeg

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)

PROJECT PAGE

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