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Format

Graphics Interchange Format

Summary

Name
Graphics Interchange Format
Version
89a
Identifiers
  • Apple Uniform Type Identifier: com.compuserve.gif
  • PUID: fmt/4
  • MIME: image/gif
Format type
Image (Raster)
Disclosure
Full
Description
The Graphics Interchange Format (GIF) is a raster image format developed by Compuserve, primarily for use on the internet. A GIF file begins with a Header section and a Logical Screen Descriptor section. This is followed by one or more Image sections, and the file is terminated by a Trailer. GIF supports bit depths between 1 and 8 bits (i.e. up to 256 colours) and supports features such as interlacing and transparency. Images are always stored using lossless LZW compression. GIF 89a introduced a number of new features, including a series of optional Control Extensions, which can be used to control the rendering of images within a file.
Release date
31 Jul 1990
Format encoding
Binary
File extensions
gif
Submitted by
Digital Preservation Department / The National Archives
Developed by
Compuserve Incorporated

Relationships

Is subsequent version of

Internal signatures

GIF 1989a

Description
header & trailer

Byte sequences

Min Frag Length
Absolute from BOF
Offset
0
Max offset
0
Byte Sequence
474946383961
Endianness
Little-endian
Min Frag Length
Absolute from EOF
Offset
0
Max offset
4
Byte Sequence
3B
Endianness
Little-endian

Changelog

  • V84

    Release date
    21 January 2016
    • Updated

      Graphics Interchange Format 89a: Added small max EOF offset to account for rare edge cases where null bytes appear after EOF marker.

  • V81

    Release date
    18 February 2015
    • Updated

      Graphics Interchange Format 89a: Description amended.