CCITT Group 4

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−	[[CCITT Group 4]] is a widely used lossless compression algorithm used for bitonal images. It is frequently used in [[TIFF]] images created by scanning bitonal images.	+	[[CCITT Group 4]] is a widely used lossless compression algorithm used for bitonal images. It is also known as '''T.6''', '''Fax 4''', and '''ITU-T Fax Group 4'''. It is frequently used in [[TIFF]] images created by scanning bitonal images.
−	== References ==	+	It is based on [[Modified Modified READ]] (MMR) compression.
		+
		+	== Related formats ==
		+	In a [[TIFF]] file, compression type 4 is CCITT Group 4.
		+
		+	In theory, CCITT Group 4 can be used in [[SPIFF]] files (compression type 3).
		+
		+	== See also ==
		+	* [[CCITT Group 3]]
		+
		+	== Specifications ==
	* [http://www.itu.int/rec/T-REC-T.6-198811-I/en T.6 : Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus]		* [http://www.itu.int/rec/T-REC-T.6-198811-I/en T.6 : Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus]
		+
		+	== References ==
	* [http://www.digitalpreservation.gov/formats/fdd/fdd000136.shtml ITU-T Group 4 FAX Compression (T.6), from Library of Congress resource on Sustainability of Digital Formats]		* [http://www.digitalpreservation.gov/formats/fdd/fdd000136.shtml ITU-T Group 4 FAX Compression (T.6), from Library of Congress resource on Sustainability of Digital Formats]

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Revision as of 18:00, 26 February 2013

File Format
Name	CCITT Group 4
Ontology	Electronic File Formats Compression CCITT Group 4
PRONOM	x-cmp/15

CCITT Group 4 is a widely used lossless compression algorithm used for bitonal images. It is also known as T.6, Fax 4, and ITU-T Fax Group 4. It is frequently used in TIFF images created by scanning bitonal images.

It is based on Modified Modified READ (MMR) compression.

Contents 1 Related formats 2 See also 3 Specifications 4 References

Related formats

In a TIFF file, compression type 4 is CCITT Group 4.

In theory, CCITT Group 4 can be used in SPIFF files (compression type 3).

See also

• CCITT Group 3

Specifications

• T.6 : Facsimile coding schemes and coding control functions for Group 4 facsimile apparatus

References

• ITU-T Group 4 FAX Compression (T.6), from Library of Congress resource on Sustainability of Digital Formats