This submodule keep the GIF encode/decode capabilities
of the Image module.
GIF is a common image storage format,
usable for a limited color palette - a GIF image can
only contain as most 256 colors - and animations.
Simple encoding:
encode , encode_trans
Advanced stuff:
render_block , header_block ,
end_block , netscape_loop_block
Very advanced stuff:
_render_block , _gce_block