AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

1994.12.14 22:00 "JBIG compression", by Kyriakos Georgiou
1994.12.14 23:51 "Re: JBIG compression", by Sam Leffler
1994.12.16 18:00 "Re: JBIG compression", by Fredrik Lundh
1994.12.16 21:02 "Re: JBIG compression", by Kyriakos Georgiou
1994.12.16 21:17 "Re: JBIG compression", by Sam Leffler
1994.12.16 22:04 "Re: JBIG compression", by Rick Richardson
1994.12.16 22:18 "Re: JBIG compression (really G3/G4 decompression)", by Sam Leffler
1994.12.15 09:59 "Further G4 improvement", by Karsten Spang

1994.12.16 18:00 "Re: JBIG compression", by Fredrik Lundh

My understanding is that JBIG requires the licensing of several patents. This makes it an unlikely candidate for a free software package such as mine.

JBIG relies heavily on arithmetic coding, an entropy coding method patented by IBM. The JBIG arithmetic coder is identical to the one defined in the JPEG standard. Luckily, JPEG also allows Huffman coding, making it possible for the IJG to provide a public domain implementation from which arithmetic coding has been left out.

Talking about licensing; what applies to the LZW compression implemented in LibTIFF?

        /F

BTW: I'm not that sure that JBIG should be stuffed into TIFF at all; the forthcoming ISO SPIFF standard merges JPEG, JBIG and Group 3/4 into one very complete interchange format.