GIF - Graphics Interchange Format
[File Formats]

Collaboration diagram for GIF - Graphics Interchange Format:


Copyright (c) 1987,1988,1989,1990 CompuServe Incorporated.
GIF is a Service Mark property of CompuServe Incorporated.
Graphics Interchange Format Programming Reference, 1990.
LZW Copyright Unisys.
Patial Internal Implementation.
Decoding and encoding code were extracted from GIFLib 1.0.
Copyright (c) 1989 Gershon Elber.


    Data Types: Byte
    Color Spaces: MAP only, (Gray and Binary saved as MAP)
      LZW - Lempel-Ziv & Welch      [default]
    Can have more than one image.
    No alpha channel.
    Internally the lines are arranged from top down to bottom.

      ScreenHeight, ScreenWidth IM_USHORT (1) screen size [default to the first image size]
      Interlaced IM_INT (1 | 0) default 0
      Description (string)
      TransparencyIndex IM_BYTE (1)
      XScreen, YScreen IM_USHORT (1) screen position
      UserInput IM_BYTE (1) [1, 0]
      Disposal (string) [UNDEF, LEAVE, RBACK, RPREV]
      Delay IM_USHORT (1) [time to wait betweed frames in 1/100 of a second]
      Iterations IM_USHORT (1) (NETSCAPE2.0 Application Extension) [The number of times to repeat the animation. 0 means to repeat forever. ]

      Attributes after the last image are ignored.
      Reads GIF87 and GIF89, but writes GIF89 always.
      Ignored attributes: Background Color Index, Pixel Aspect Ratio,
                          Plain Text Extensions, Application Extensions...