GIF -- Graphics Interchange Format

GDAL supports reading and writing of normal, and interlaced GIF files. Gif files always appear as having one colormapped eight bit band. GIF files have no support for georeferencing.

A GIF image with transparency will have that entry marked as having an alpha value of 0.0 (transparent). Also, the transparent value will be returned as the NoData value for the band.

If an ESRI world file exists with the .gfw, .gifw or .wld extension, it will be read and used to establish the geotransform for the image.

Creation Issues

GIF files can only be created as 1 8bit band using the "CreateCopy" mechanism. If written from a file that is not colormapped, a default greyscale colormap is generated. Tranparent GIFs are not currently supported on creation.

WORLDFILE=ON: Force the generation of an associated ESRI world file (.wld).

Interlaced (progressive) GIF files can be generated by supplying the INTERLACING=ON option on creation.

Starting with GDAL 1.7.0, GDAL's internal GIF support is implemented based on source from the giflib 4.1.6 library (written by Gershon Elbor, Eric Raymond and Toshio Kuratomi), hence generating LZW compressed GIF.

The driver was written with the financial support of the DM Solutions Group, and CIET International.