A script to reduce the size of PNG images significantly. The code is based on Crush by Christopher Simpkins and has been adapted to Linux by refactoring it. As the code base shows significant differences the name has also been changed.
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bc
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file
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butteraugli (optional)
Usage:
pngpetite <options> <png-image> ...
Options:
-h | --help This message
-r | --replace Replace file with processed one
Implies -d
-d | --dest <path> Place images in given path
Implies -r
-S | --no-stats Don't print stats
-q | --quiet Don't print stats and progress
-V | --version Print version and exit
Description:
Insane(ly slow but wicked good) PNG image optimization
Built with pngquant and zopflipng optimizershappy-sun-pngpetite.pngpngpetit happy-sun.png
Original (KB) Stage1 (KB) Final (KB) Saved (KB) Saved % Time (sec) Image Name
------------- ------------- ------------- ------------- ------------- ------------- -------------
25.639 16.186 13.857 11.781 45.951 22.204 happy-sun.png
happy-sun.pngpngpetit --replace happy-sun.png
Original (KB) Stage1 (KB) Final (KB) Saved (KB) Saved % Time (sec) Image Name
------------- ------------- ------------- ------------- ------------- ------------- -------------
25.639 16.186 13.857 11.781 45.951 22.204 happy-sun.png
pngpetite/happy-sun.pngpngpetit --dest pngpetite happy-sun.png
Original (KB) Stage1 (KB) Final (KB) Saved (KB) Saved % Time (sec) Image Name
------------- ------------- ------------- ------------- ------------- ------------- -------------
25.639 16.186 13.857 11.781 45.951 22.204 happy-sun.png
originals and place them in directory pngpetite.pngpetite --dest pngpetite original/*png
Original (KB) Stage1 (KB) Final (KB) Saved (KB) Saved % Time (sec) Image Name
------------- ------------- ------------- ------------- ------------- ------------- -------------
695.867 695.867 658.104 37.764 5.427 20.190 original/beach.png
25.639 16.186 13.857 11.781 45.951 22.197 original/happy-sun.png
54.101 29.885 27.244 26.856 49.642 8.097 original/shinkansen-n700.png
docker run \
--rm \
--tty \
--volume "$(pwd)":"$(pwd)" \
--workdir "$(pwd)" \
--user "$(id -u):$(id -g)" \
uroesch/pngpetite <PNG image> [<PNG image> ...]Or simply use the docker-pngpetite wrapper script found in the bin
directory.
bin/docker-pngpetite <PNG image> [<PNG image> ...]pngpetite is not suited for every type of picture. Especially photographic images
may not yield high savings.
To visualize the differences between the original image and the optimized one,
google’s butteraugli tools is used.
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ℹ️
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The values presented below were done on an Ubuntu 20.10 machine with:pngquant 2.12.0 (January 2018)zopfli 1.0.3Your milage may vary. |
| Original (KB) | Stage1 (KB) | Final (KB) | Saved (KB) | Saved % | Butteraugli Score |
|---|---|---|---|---|---|
443.642 |
164.648 |
150.155 |
293.486 |
66.154 |
2.676426 |
Noticeable is that at stage 1 pngquant shrinks the image by 62% in older versions
photographic pictures did only yield a reduction in size.
At stage 2 zopflipng is able to squeeze another 4% from its compression algorithm.
Comparing the two images with butteraugli shows a large differences especially in
the sunset section of the image.
| Original (KB) | Stage1 (KB) | Final (KB) | Saved (KB) | Saved % | Butteraugli Score |
|---|---|---|---|---|---|
567.165 |
204.628 |
192.016 |
375.149 |
66.145 |
3.551921 |
The heatmap shows clearly where the biggest differences occur during the processing. Notable are they eyes and the background. The fur is very similar to the originial image.
| Original (KB) | Stage1 (KB) | Final (KB) | Saved (KB) | Saved % | Butteraugli Score |
|---|---|---|---|---|---|
30.321 |
17.326 |
15.683 |
14.639 |
48.279 |
0.309227 |
The images are nearly similar the butteraugli heatmap does not have any red in it just a few areas in the face of the sun.
- beach.png
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CC0 Public Domain pixabay.com
- cat.png
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CC0 Public Domain pixabay.com
- happy-sun.png
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CC0 Public Domain opencliapart.org
- shinkansen-n700.png
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CC0 Public Domain opencliapart.org