https://github.com/subzey/zopfli-png

PNG optimizer using zopfli deflate packer
https://github.com/subzey/zopfli-png

Last synced: 14 days ago
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PNG optimizer using zopfli deflate packer

• Host: GitHub
• URL: https://github.com/subzey/zopfli-png
• Owner: subzey
• Archived: true
• Created: 2013-03-02T18:00:49.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2019-12-23T14:47:28.000Z (almost 5 years ago)
• Last Synced: 2024-07-31T18:18:18.709Z (3 months ago)
• Language: JavaScript
• Size: 84 KB
• Stars: 65
• Watchers: 4
• Forks: 4
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md

Awesome Lists containing this project

• awesome-images - zopfli-png

README

        
This project is no longer maintained

====================================

`zopfli-png` was a first response to utilize a brand new GZIP compressor to recompress PNGs back in the 2013.

Nowadays there are much faster, stable, just better tools to do the same job:

- [advpng](http://www.advancemame.it/comp-readme) to recompress your PNGs

- [apngopt](https://sourceforge.net/projects/apng/files/APNG_Optimizer/) for APNGs

zopfli-png

==========

PNG optimizer using zopfli deflate packer

Description

-----------

Recently [zopfli](https://code.google.com/p/zopfli/) DEFLATE algorithm was announced.

As PNG IDAT section are actually DEFLATE compressed, this algorithm can be used for

compressing PNG. This script actually does it.

Please note that neither pixel data, not filters applied to image data are not changed.

This script may be treated mostly like DeflOpt replacement. That means, PngOUT or other

PNG compressing tools must be applied before this one.

Requirements

------------

This is a node.js script. So it requires [node.js](http://nodejs.org/) first of all.

This package includes zopfli.exe. In other OSes it is much easier to use `gcc`, so go ahead,

`git pull https://code.google.com/p/zopfli/` and `make` it.

Zopfli binary may be placed in `bin/` subdirectory or set in `path`.

Usage

-----

`node zopfli-png.js [options] file1.png [file2.png ...]`

where `options` is one or more modifiers.

The most important are iteration count modifiers, these are passed to zopfli binary:

`--i5`

`--i10`

`--i15`

`--i25`

`--i50`

`--i100`

`--i250`

`--i500`

`--i1000`

Higher the number, slower and better the compression.

Other options:

`--force`, force write even if resulting PNG file is bigger. Zopfli is darn good, but it is not a silver bullet.

`--silent`, do not show any messages. Except maybe most wild errors.

`--splitlast`, do block splitting last instead of first. This option may reduce the size of output file. Requires Zopfli 1.0.0 (April 25, 2013)

`--help`, if you want to read this section once again.

Licence

-------

Awesome zopfli algorithm and implementation are authored by Jyrki Alakuijala, Ph.D.

and Lode Vandevenne, M.Sc. and licensed with [Apache Licence 2.0](http://www.apache.org/licenses/LICENSE-2.0).

Other wrapping code (i.e., `zopfli-png.js`, `crc32crypto.js` and `pngstream.js`)

is licenced with [WTFPL Licence 2.0](http://www.wtfpl.net/txt/copying/)