Zopfli is data compression software that encodes data into DEFLATE , gzip and zlib formats. It compresses data with a higher compression ratio than other DEFLATE and zlib implementations, but requires significantly more time to create an archive [1] . The software was released by Google in February 2013 as a free library under the Apache license version 2.0 [2] . The name Zöpfli is a Swiss diminutive of the word - the name of Swiss bread [3] .
| Zopfli archive | |
|---|---|
| Type of | data compression utility |
| Author | Laude Vandevenne and Jyrki Alakuyala |
| Developers | |
| Written on | C ++ , C |
| Interface | library |
| operating system | cross-platform |
| Hardware platform | cross-platform |
| Latest version | 1.0.2 |
| Generated File Formats | , and |
| License | Apache 2.0 License |
| Site | github.com/google/zopfli |
Content
Properties and Usage
Zopfli can create both a clean DEFLATE data stream and DEFLATE data placed in gzip or zlib formats. By default, the program compresses in 15 iterations, but can be configured to perform fewer or more iterations to maintain a balance between time and compression ratio.
At default settings, the result of Zopfli is usually 3–8% less than the result of zlib with the maximum available compression ratio, but compression takes about 80 times longer [2] [1] . The time of unpacking archives created by Zopfli and zlib is practically the same [4] .
Due to its much slower compression, zopfli is less suitable for use on-the-fly and is usually used for one-time compression of static data [5] [6] . This is particularly true for web content transmitted using DEFLATE-based and web content in DEFLATE-based formats such as PNG or WOFF [7] .
Technology
Greater information density is achieved through more complete compression techniques. The method is based on iterative modeling of entropy and shortest path search algorithms for finding the path of the minimum bit cost in the graph of all possible DEFLATE representations of uncompressed data [8] .
History
Zopfli is based on an algorithm created by Jürki Alakuyala. The research implementation of Zopfli was created by Jyrki Alakuyala and Laude Vandevenna, Google employees. The first public version of the program was released in February 2013. Version 1.0 was released in April 2013 [9] .
See also
- 7-zip
Notes
- ↑ 1 2 A Look At Zopfli, Google's Open Source Compression Algorithm | Lifehacker Australia . Lifehacker.com.au (March 3, 2013). Date of treatment September 29, 2015.
- ↑ 1 2 Compress data more densely with Zopfli - Google Developers Blog . Googledevelopers.blogspot.com (February 28, 2013). Date of treatment May 1, 2013.
- ↑ Alexander Neumann. Zopfli: Neue Kompressionsbibliothek von Google | heise Developer (German) . Heise.de . Date of treatment September 29, 2015.
- ↑ Alakuijala, Jyrki Data compression using Zopfli unopened (inaccessible link) . Date of treatment September 6, 2015. Archived March 5, 2016.
- ↑ Dean Hume. Improved Compression Ratios Using Zopfli Neopr (June 1, 2015). Date of treatment September 6, 2015.
- ↑ Sharwood, Simon Google open sources very slow compression algorithm . The Register (2013).
- ↑ Ilya Grigorik. Google Fonts recently switched to using new Zopfli compression algorithm . Google+ (January 9, 2014). Date of treatment June 6, 2015.
- ↑ Zopfli: Google's new data compression algorithm | Digit.in unopened . Thinkdigit.com (March 1, 2013). Date of treatment September 29, 2015.
- ↑ Release Zopfli-1.0.0 . Github.com (April 25, 2013). Date of treatment September 6, 2015.