The TIFF format is flexible enough to allow lots of different coding methods, within it. There are TIFF

       This  manual  page was generated by the Netpbm tool 'makeman' from HTML source.  The master documentation
       is at

              http://netpbm.sourceforge.net/doc/faxformat.html

netpbm documentation                            03 December 2008                                  FaxFormats(1)

       The  TIFF format is flexible enough to allow lots of different coding methods, within it.  There are TIFF
       subformats for MH, MR, and MMR, among others.  These are particularly useful when you receive a fax as  a
       TIFF file.

       tifftopnm recognizes and can convert from any of these.

       pamtotiff can convert to any of these; you use command options to choose which.