| |
| Compression Name |
CCITT T.4 |
| Other names |
CCITT Group 3 |
| Identifier(s) |
PUID:
x-cmp/14
|
| Family |
|
| Description |
Officially known as CCITT T.4, Group 3 is a compression algorithm developed by the International Telegraph and Telephone Consultative Committee in 1985 for encoding and compressing 1-bit (monochrome) image data. Its primary use has been in fax transmission, and it is optimised for scanned printed or handwritten documents. Group 3 is a lossless algorithm, of which two forms exist: one-dimensional (which is a modified version of Huffman encoding) and two-dimensional, which offers superior compression rates. Due to its origin as a data transmission protocol, Group 3 encoding incorporates error detection codes. Group 3 compression is most commonly used in the TIFF file format. |
| Lossiness |
Lossless |
| Released |
01 Jan 1985 |
| Withdrawn |
|
| Developed by |
 International Telecommunication Union
|
| Supported by |
|
| Documentation |
CCITT Blue Book, 1989, Volume VII, Fascicle VII.3: Terminal equipment and protocols for telematic services, recommendations T.0 - T.63 |
| Rights |
|
| Note |
|
 Top of page
|
|
Details: File format summary
: detailed report on compression type 
