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Format

Computer Graphics Metafile ASCII

Summary

Name
Computer Graphics Metafile ASCII
Version
1
Identifiers
  • MIME: image/cgm
  • PUID: x-fmt/142
Format type
  • Image (Raster)
  • Image (Vector)
  • Text (Structured)
Description
Computer Graphics Metafile (CGM) is a standardized platform-independent format used for the interchange of raster and vector data. CGM was developed under the auspices of the International Standards Organization (ISO) and the American Standards National Institute (ANSI). It is also used in conjunction with a variety of input and output devices. Although CGM incorporates extensions designed to support raster data storage, files in CGM format are used primarily to store vector information. CGM files typically contain either bitmap or vector data, but rarely both. It uses Clear Text Encoding. File format specifications available at http://standards.iso.org/ittf/PubliclyAvailableStandards/c044114_ISO_IEC_8632-1_1999_Cor_1_2006%28E%29.pdf
File extensions
cgm
Source
Digital Preservation Department / The National Archives

Internal signatures

Computer Graphics Metafile (Clear Text) Version 1 No.1

Note
Element name begmf (Begin Metafile) with any letter in the element name in upper or lower case, followed by any number of bytes, followed by version (MFVERSION{1}1 or mfversion{1}1, or any upper/lower case combination). Trailer endmf{0-1}; (with any letter in the element name in upper or lower case) that can be followed by a comment

Byte sequences

Min Frag Length
Absolute from BOF
Offset
0
Max offset
None
Byte Sequence
42(45|65)(47|67)(4D|6D)(46|66)*(4D|6D)(46|66)(56|76)(65|45)(52|72)(53|73)(49|69)(4F|6F)(4E|6E){1}31
Endianness
None
Min Frag Length
Absolute from EOF
Offset
0
Max offset
2048
Byte Sequence
45(4E|6E)(44|64)(4D|6D)(46|66){0-1}3B
Endianness
None

Computer Graphics Metafile (Clear Text) Version 1 No.2

Note
Element name begmf (Begin Metafile) with any letter in the element name in upper or lower case, followed by any number of bytes, followed by version (MFVERSION{1}1 or mfversion{1}1, or any upper/lower case combination). Trailer endmf{0-1}; (with any letter in the element name in upper or lower case) that can be followed by a comment

Byte sequences

Min Frag Length
Absolute from BOF
Offset
0
Max offset
None
Byte Sequence
42(45|65)(47|67)(4D|6D)(46|66)*(4D|6D)(46|66)(56|76)(65|45)(52|72)(53|73)(49|69)(4F|6F)(4E|6E){1}31
Endianness
None
Min Frag Length
Absolute from EOF
Offset
0
Max offset
2048
Byte Sequence
65(4E|6E)(44|64)(4D|6D)(46|66){0-1}3B
Endianness
None

Computer Graphics Metafile (Clear Text) Version 1 No.3

Note
Element name begmf (Begin Metafile) with any letter in the element name in upper or lower case, followed by any number of bytes, followed by version (MFVERSION{1}1 or mfversion{1}1, or any upper/lower case combination). Trailer endmf{0-1}; (with any letter in the element name in upper or lower case) that can be followed by a comment

Byte sequences

Min Frag Length
Absolute from BOF
Offset
0
Max offset
None
Byte Sequence
62(45|65)(47|67)(4D|6D)(46|66)*(4D|6D)(46|66)(56|76)(65|45)(52|72)(53|73)(49|69)(4F|6F)(4E|6E){1}31
Endianness
None
Min Frag Length
Absolute from EOF
Offset
0
Max offset
2048
Byte Sequence
45(4E|6E)(44|64)(4D|6D)(46|66){0-1}3B
Endianness
None

Computer Graphics Metafile (Clear Text) Version 1 No.4

Note
Element name begmf (Begin Metafile) with any letter in the element name in upper or lower case, followed by any number of bytes, followed by version (MFVERSION{1}1 or mfversion{1}1, or any upper/lower case combination). Trailer endmf{0-1}; (with any letter in the element name in upper or lower case) that can be followed by a comment

Byte sequences

Min Frag Length
Absolute from BOF
Offset
0
Max offset
None
Byte Sequence
62(45|65)(47|67)(4D|6D)(46|66)*(4D|6D)(46|66)(56|76)(65|45)(52|72)(53|73)(49|69)(4F|6F)(4E|6E){1}31
Endianness
None
Min Frag Length
Absolute from EOF
Offset
0
Max offset
2048
Byte Sequence
65(4E|6E)(44|64)(4D|6D)(46|66){0-1}3B
Endianness
None

Changelog

  • Updated in V55

    Release date
    4 January 2012

    Computer Graphics Metafile ASCII 1: Format description information supplied by NARA Information Services/Applied Research Division, The National Archives and Records Administration.

  • Added in V45

    Release date
    6 December 2010

    Computer Graphics Metafile ASCII 1.: Record title updated to distinguish different versions.

    Computer Graphics Metafile ASCII 1: Signature submitted by Georgia Tech Research Institute, USA.