Developer(s) Thomas Boutell Operating system | Written in C | |
Initial release 1994; 23 years ago (1994) Stable release 2.2.3 / July 22, 2016; 7 months ago (2016-07-22) Repository |
The GD Graphics Library is a graphics software library by Thomas Boutell and others for dynamically manipulating images. Its native programming language is ANSI C, but it has interfaces for many other programming languages. It can create GIFs, JPEGs, PNGs, and WBMPs. Support for drawing GIFs was dropped in 1999 when Unisys revoked the royalty-free license granted to non-commercial software projects for the LZW compression method used by GIFs. When the Unisys patent expired worldwide on July 7, 2004, GIF support was subsequently re-enabled.
GD originally stood for "GIF Draw". However, since the revoking of the Unisys license, it has informally stood for "Graphics Draw".
GD can create images composed of lines, arcs, text (using program-selected fonts), other images, and multiple colors. Version 2.0 adds support for truecolor images, alpha channels, resampling (for smooth resizing of truecolor images), and many other features.
GD supports numerous programming languages including C, PHP, Perl, Python, OCaml, Tcl, Lua, Pascal, GNU Octave, REXX, Ruby and Go. In addition, the "Fly" command line interpreter allows for image creation ("on the fly") using GD. GD scripts can thus be written in potentially any language and run using this tool.
GD is extensively used with PHP, where a modified version supporting additional features is included by default as of PHP 4.3 and was an option before that. As of PHP 5.3, a system version of GD may be used as well, to get the additional features that were previously available only to the bundled version of GD.
Example
The following is an example which outputs a 3D looking pie chart (from the PHP GD documentation on the imagefilledarc() function).