libpng is the official

Portable Network Graphics Portable Network Graphics (PNG, officially pronounced , colloquially pronounced ) is a raster graphics, raster-graphics file graphics file format, format that supports lossless data compression. PNG was developed as an improved, non-patented ...

(PNG)

reference A reference is a relationship between objects in which one object designates, or acts as a means by which to connect to or link to, another object. The first object in this relation is said to ''refer to'' the second object. It is called a ''nam ...

library A library is a collection of Book, books, and possibly other Document, materials and Media (communication), media, that is accessible for use by its members and members of allied institutions. Libraries provide physical (hard copies) or electron ...

(originally called pnglib). It is a platform-independent library that contains C functions for handling PNG images. It supports almost all of PNG's features, is extensible, and has been widely used and tested for over 28 years. libpng is dependent on

zlib zlib ( or "zeta-lib", ) is a software library used for data compression as well as a data format. zlib was written by Jean-loup Gailly and Mark Adler and is an abstraction of the DEFLATE compression algorithm used in their gzip file compre ...

for data compression and decompression routines. libpng is released under the libpng license, a permissive free software licence, and is

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

. It is frequently used in both free and proprietary software, either directly or through the use of a higher level image library. the latest versions in the 1.6.x and 1.5.x branches were considered as release versions, while 1.4.x, 1.2.x, and 1.0.x were considered as legacy versions getting only security fixes. All vulnerability warnings and crash bugs are published on the main page.

References

External links

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howto
on writing PNG images using libpng C (programming language) libraries Free software programmed in C Graphics libraries {{Graphics-software-stub