JBIG2 and JBIG compared
Introduced as an ITU standard in 1993, JBIG (also called JBIG1) never achieved the acceptance that TIFF G4 enjoyed even though it provided a 20-30% reduction in file size over TIFF G4. Such a reduction rate never generated sufficient enthusiasm among the digital imaging community to justify broad-based industry support. Consequently, JBIG was mostly used for bitonal image compression on a very limited range of (mostly Japanese) MFP devices and digital copiers.
In contrast, the digital media industry has readily received the JBIG2 standard. Almost from the time of its introduction, JBIG2 was supported for bitonal compression in the JPEG 2000 Part 6 specifications, and as a compression filter in Adobe PDF. It quickly became the format of choice for a number of document-heavy organizations including legal, media, financial, scanning and banking firms.
One advantage held by both JBIG and JBIG2 over TIFF G3 and G4 is the JBIG formats' ability to use arithmetic coding instead of Huffman coding. Again, the key difference is the higher compression ratio arithmetic coding can bring to the JBIG standard. Arithmetic coding allows for data to be represented by a fraction of a bit. In comparison, Huffman coding requires whole bits to represent runs in the image, resulting in a lower compression ratio for the TIFF formats.
New Features of JBIG2JBIG2 introduced a number of features not available in JBIG, including:
- File size reduction of 90% or more.
- Support for several lossy and lossless compression modes.
- Machine learning of font classes.
- Readily available viewer support, Adobe Reader, when the JBIG2 file is PDF-wrapped.