JBIG2 and TIFF compared
The TIFF Group 3 (TIFF G3) standard was introduced in 1980. It gained wide acceptance in the digital imaging world as the "go to" standard for fax-based transmission. The TIFF Group 4 (TIFF G4) standard of 1985 remains the effective standard for archiving and digital scanners.
Due to the higher compression rates offered by JBIG2, digital imaging devices that currently utilize a TIFF compression filter are expected to convert to a JBIG2 filter for bitonal scans in the near future. Consider this example: TIFF G4 is often 15x smaller than a raw 300 dpi (dots per inch) black and white image file. Yet a compact JBIG2 version of the same file will be 5x - 15x smaller than the TIFF G4 file.
The comparison is even more striking when the original file has an electronic origin (for example, those generated by, and converted from, a Corel Suite or Microsoft Office application). In these cases, JBIG2 compression rates can be 20x - 30x smaller than a comparable TIFF G4 encoding.
Transitioning from TIFF to JBIG2
There's another reason behind the likely transition from TIFF to JBIG2: a JBIG2-encoded file only shows a minimal increase in size with increased scanner resolution. In contrast, TIFF encoding generates a linear increase in file size corresponding to the increase in scanning resolution. So, in practical terms a 300 dpi TIFF file is usually 50% or so larger than its equivalent 200 dpi TIFF file. In contrast, a 300 dpi JBIG2 file will only be marginally larger than its equivalent 200 dpi file - and in cases where some advanced JBIG2 features can be applied, the JBIG2 300 dpi file may actually be smaller than its 200 dpi equivalent with no loss of accuracy or quality.