CCITT Group 4

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.

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