> Jörg Henne <[email protected]> hat am 24. August 2017 um 10:08 geschrieben: > > > > Am 23.08.2017 um 18:40 schrieb Andreas Lehmkuehler: > > readded dev@pdfbox > > > > Am 22.08.2017 um 19:14 schrieb Jörg Henne: > >> Am 19.08.2017 um 17:07 schrieb Andreas Lehmkuehler: > >> > >>> The following files don't have a license header: > >>> > >> Good catch. Tracked as https://github.com/levigo/jbig2-imageio/issues/46 > >> > >>> What about the binary test files in src/test/resources/? I assume > >>> their license is cleared as well, isn't it? > >>> > >> That's what I assumed as well, but upon re-checking, things no longer > >> seem to be so clear. I'm tracking this question as > >> https://github.com/levigo/jbig2-imageio/issues/48 > >> Maybe you guys can help me with this problem or let me know how you > >> deal with it. > > Is there any jbig2-viewer available? > In theory, yes, for example XnView supports JBIG2 via jbig2dec.exe. In > reality, support for the various cases covered in the test suite is > rather spotty: many of the images cannot be decoded with XnView. So, > strange as it might seem, I don't know of any reliable stand-alone JBIG2 > viewer. > > However, obviously those images can be decoded using the plugin. I've > attached PNG versions of them to a comment on the above issue: > https://github.com/levigo/jbig2-imageio/issues/48#issuecomment-324556311 Cool, I've already thought about converting them myself, but you were faster. Thanks. I'll have a look after the weekend as my time will be limited the next few days.
> > Are these testfiles somehow special, do they trigger some special > > processing within the plugin or are they just a bunch of jbig2 files > > and could be replaced by others > JBIG2 isn't quite as simple as, say, PNG. There are several entropy > coding options (Arithmetic/MQ, Huffman) several different segment types > and several ways to maintain, refine and reference shape dictionaries. > Therefore there a large number of code paths need to be covered in the > tests. Since it is rather hard to generate all those possible > combinations (no single encoder library will use all of them) the > refrerence library provides (provided?) a convenient way of achieving > decent test coverage. OK, so we should try to keep as much as possible of those data. > >> The files seem to fall into three categories: > >> 1. 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. > >> - Files containing representations of public U.S. government > >> documents should be in the public domain: > >> https://en.wikipedia.org/wiki/Copyright_status_of_work_by_the_U.S._government > >> - The same applies to representations of U.S. patents: > >> https://en.wikipedia.org/wiki/Copyright_on_the_content_of_patents_and_in_the_context_of_patent_prosecution > >> > >> > >> - 004.jb2 and 005.jb2 seem problematic but may be covered by some > >> exemption. > >> - amb.bmp no idea > > amb.bmp seems problematic as it looks like a promo photo of Ally > > McBeal aka Callista Flockhart. > You seem to be more up to speed regarding TV characters. I certainly > didn't recognise the person in the photo :-) Maybe I'm old enough to know that TV-show from the late 90's > Losing this image would be bad, though, since it is the only halftone > region sample bitstream in there. Maybe, we should think about a README which expains the origin of some/all of the test files > >> 2. 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. > > >> 3. Files with content so trivial that copyright should not be an > >> issue, i.e. fragments of bitstreams, isolated segments, trivial test > >> images > > This isn't a question of copyright but of license and/or privacy. > The files in this category are sampledata_page(1,2,3).jb2. The content > is obviously not a matter of privacy. Regarding the license I am > currently asking around whether anyone still knows where this came from > (unfortunately we lost some very early RCS history from before we > open-sourced the component). > > Jörg Andreas --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
