GD2 image format

GD2 image format is a raster graphics file format associated with the GD graphics library (a.k.a. LibGD), originally developed by Thomas Boutell. Refer to GD image format for more information about the GD library. GD2 format was introduced in GD v1.5.

GD2 image format is a special purpose format, and a companion to the older GD image format. GD2 is more advanced, and supports efficiently reading a portion of a large image. Some GD2 files use zlib compression.

Identification
A GD2 file starts with signature bytes.

Specifications

 * Refer to the source code comments in modern versions of the gd_gd2.c file.

Software

 * LibGD: Refer to GD image format (v1.5+).

Links

 * Refer to GD image format.