The CCITT Group 3 Facsimile is a data file containing Group 3 FAX data in "raw" form (i.e. no header).
The default extension for CCITT Group 3 files is G3
Supporting Platforms and Applications
This format is used by numerous FAX applications on a wide range of platforms.
The FAX data is assumed to have a data row width of max 1728 pixels and a height of minimum 100 pixels.