GD Graphics Library

From Wikipedia, the free encyclopedia

The GD Graphics Library is a 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, O'Caml, Tcl, Lua, Pascal, Octave and REXX. There is also a tool called fly which allows access to GD from any language through a command-line program.

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.

[edit] See also

[edit] External links

GD Graphics Library
Image Functions (PHP), support in PHP

[edit] Tutorials

Creating Images with GD Library An example of image generation, using a png image on the server and adding .ttf fonts
Introductory GD tutorials A small selection of tutorials for creating and altering images in PHP
[1] Introduction to PHP Image Functions
Introduction to Image Manipulation in PHP + GD