2007.05.13 17:47 "[Tiff] JBIG2 compressed TIF question about bpp", by t t

2007.05.14 21:24 "Re: [Tiff] Re: JBIG2 in TIFF", by Bob Friesenhahn

JBIG2 compression in TIFF was only recently added as an extension to the TIFF/IT spec via an ISO addendum to TIFF/IT. As far as I'm aware, no attempt has been made yet to support it in tifflib (if anyone is thinking about this, I'd like to talk to them, as I'm interested in supporting it in SwiftView - just as we already support JBIG2 in PDF.)

CVS libtiff supports JBIG1 via JBIG-KIT. I don't think JBIG-KIT supports JBIG2 yet.

Unfortunately, JBIG-KIT is GPL licensed (not even LGPL). This makes it difficult to use in many cases. Some years ago, the JBIG-KIT author expressed concern to me that ImageMagick was using JBIG-KIT and RMS was involved in the discussion. The concern was if ImageMagick was violating GPL by using JBIG-KIT via a loadable module. RMS said that using a loadable module was not sufficient to avoid GPL. The upshot was that ImageMagick was in the clear since it was already observing GPL-required distribution rules.

I have heard that use of JBIG2 is limited by patents.

Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/