CCITT Group 4

File Format
Name	CCITT Group 4
Ontology	Electronic File Formats Compression CCITT Group 4
LoCFDD	fdd000136
PRONOM	x-cmp/15

CCITT Group 4 is a widely-used lossless compression algorithm for bitonal images. It is also known as T6, T.6, Fax4, G4, Group 4, or ITU-T Fax Group 4. It is frequently used in TIFF images created by scanning bitonal images.

It uses Modified Modified READ (MMR) compression. MMR is probably another synonym for CCITT Group 4.

Related formats

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

Other formats that can use CCITT Group 4 compression include PDF and SPIFF.

See also

• CCITT Group 3

Specifications

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

Software

• Farbfeld Utilities
• ImageMagick (specify the file format as "GROUP4")

References

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