The following files come from the official reference suite. It is currently no longer available from the original source, but has been mirrored here for the jbig2dec library
amb.bmp is a dithered representation of a promotional photo of Ally Mc Beal (Callista Flockhart)
002.jb2 is the first page of US Patent 6,122,289
003.jb2 seems to be from a report concerning the Lewinsky scandal
004.jb2 and 005.jb2 are excerpted pages from "Libertarianism: A Primer" by David Boaz, a copyrighted work from 1997
006.jb2 is a page from an SEC registration
007.jb2 see 042*.jb2 above
_These sample bitstreams are referenced in many places, e.g. here but not all include the actual files. Jbig2dec is licensed under the GPL but I doubt that this applies to the sample images as well._
The following files/bitstreams are reproduced as hex-dumps within the T.88 specification document
sampledata*.jb2 contains minimal sample bitstreams for varoius segment types
The heritage of the following files is known, but the copyright status is not clear
201231100*.jb2 seems to be an official and public record from the state of Arizona. License has been granted here: https://code.google.com/archive/p/jbig2-imageio/issues/11, although it is not clear whether the granter had the right to do so.
Files from the original test suite. While the copyright status of the file isn't problematic, the status of the content seems to be muddy in some cases.
004.jb2 and 005.jb2 seem problematic but may be covered by some exemption.
amb.bmp most likely problematic (Wikipedia claims fair use on a similar picture - can we, too?). The picture seems to be a crop from a photo used in many places, but no authoritative copyright info seems to be available.
Files provided to us with the permission to use them for testing purposes
201231100*.jb2 is the only case, seems to be a public U.S. document anyway and therefore in the public domain. I have not contacted the original provider of the files for the simple reason that his or her e-mail address has been lost when the Googlecode site went into archived state.
Files with content so trivial that copyright should not be an issue, i.e. fragments of bitstreams, isolated segments, trivial test images
The following files come from the official reference suite. It is currently no longer available from the original source, but has been mirrored here for the jbig2dec library
_These sample bitstreams are referenced in many places, e.g. here but not all include the actual files. Jbig2dec is licensed under the GPL but I doubt that this applies to the sample images as well._
The following files/bitstreams are reproduced as hex-dumps within the T.88 specification document
The heritage of the following files is known, but the copyright status is not clear