libavif
12. 4. 2023Following https://web.dev/compress-images-avif/
Build (Debian GNU/Linux 11 (bullseye)) ↓
# backports must be enabled in /etc/apt/sources.list
sudo apt install -t bullseye-backports libyuv-dev libyuv0
# get the repo
git clone -b v0.11.1 https://github.com/AOMediaCodec/libavif.git
see https://github.com/AOMediaCodec/libavif/releases
cd libavif/ext
./aom.cmd
# sudo apt install ninja # if needed
cd ..
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=0 -DAVIF_CODEC_AOM=1 -DAVIF_LOCAL_AOM=1 -DAVIF_BUILD_APPS=1 ..
make
Two new files should appear: avifenc and avifdec, cp both to ~/bin (or some other $PATH)
Use ↓
Proposed for lossy
avifenc --min 0 --max 63 -a end-usage=q -a cq-level=18 -a tune=ssim jenga.png jenga.avif
and you get this 87k file:
or this 50k file:
edit: It might be reasonable to up-depth to 10 bit to make gradients better (-d 10 switch), even if input is 8 bit. 8bit RGB to 10bit YUV is supposedly lossless.
Notes ↓
It’s fast.
Film synthesis?
film-grain-test=TEST
film-grain-table=FILENAME
Test
avifenc --min 0 --max 63 -a end-usage=q -a cq-level=18 -a film-grain-test=16 -a tune=ssim jenga.png jenga3.avif
seems to add some artificial grain to image, but keeps the filesize the same. Unsure if this the same as grain synthesis in libaom.
p.s. The number is grain size (not strenght), where 1 is the smallest and 16 is the biggest. Example with film-grain-test=1:
p.s.2. It is also possible to use denoise-noise-level thing (grain synthesis).
Using slightly noisy crop of the 7d photo and high compression here (38k!) to illustrate the effect:
avifenc --min 0 --max 63 -a end-usage=q -j 8 -a cq-level=35 -a denoise-noise-level=5 -a tune=ssim fotodetail.png fotodetail.avif
Can I use for web ↓
https://caniuse.com/?search=avif
libjxl ↓
(jpeg-xl reference encoder) - Possible future alternative?
https://tonisagrista.com/blog/2023/jpegxl-vs-avif/
Build ↓
follow: https://github.com/libjxl/libjxl/blob/main/BUILDING.md
perhaps needed after install:
sudo ldconfig
Can I use for web (not at the moment) ↓
https://caniuse.com/?search=jpeg-xl
For the low bitrates and set of this 3 images, avif wins ime (in my eyes).
