[luatex] CIDSet in PDF/A documents

[Reinhard Kotucha]

On 2015-06-23 at 06:07:13 +0200, luigi scarso wrote:

 > > Hi,
 > > at
 > >
 > >   http://tracker.luatex.org/view.php?id=434
 > >
 > > Hans wrote
 > >
 > >  > pdf/a demands a cidset but we will forget about this till we find a
 > >  > proper example
 > >  >
 > >  > there is still some reported problem with some stream objects not
 > >  > properly being formatted cf. pdf/a but it is not clear what is
 > >  > going on there
 > >
 > > This message is now five years old.  Any new perceptions?
 > >
 > > I'm using a TrueType font (CharisSIL) and one of five PDF/A validators
 > > complains about a bad CIDSet.
 > >
 > > I created a small PDF file which only contains the string "abc",
 > > extracted the TTF from the PDF file, and disassembled it with TTX.
 > > Then I assembled the CIDSet manually according to the instructions
 > > given in the PDF/A-1 specification (ISO 19005-1).  I've got the same
 > > result as LuaTeX, hence it's unclear to me what's going wrong.
 > >
 > > The PDFtron
 > >
 > >   https://www.pdftron.com/
 > >
 > > validator sais
 > >
 > >   <Error Code="e_PDFA356" Message="CIDSet in subset font is incomplete"
 > > Refs="95, 101"/>
 > >
 > > I tend to believe that the validator is wrong.  On the other hand
 > > PDFtron offers software which creates PDF/A files and I can't imagine
 > > that their validator complains about their own products.
 > >
 > > Did anybody investigate?  The nasty thing is that PDF/A is for long
 > > term preservation and any file we create today has to comply with the
 > > standard unconditionally.  And for us TeX users, the fact that there
 > > are zillions of invalid PDF/A files around just because old versions
 > > of the Acrobat preflight tool ignored most errors, is not an excuse.
 > > We should do better.
 > >
 > > >From the results of my own investigations I deduce that LuaTeX
 > > provides a standard compliant CIDSet.  Maybe different people
 > > interpret the standard in a different way.  But it would be nice to
 > > know whether somebody else investigated this issue already.
 > >
 > > Regards,
 > >   Reinhard
 > >
 > >
 > which pdf/a ?

PDF/A-1b

 > https://pdfbox.apache.org/
 > 
 > says
 > """
 > Preflight
 > Validate PDF files against the PDF/A-1b standard.
 > """

PDFbox was one of the validators I used.  It didn't complain.

There is probably a newer release.  Somebody said on a mailing list
that he submitted a patch which adds object numbers to error
messages.  Sounds very reasonable and useful.

BTW, I validated both validators before.

  http://ms25.no-ip.info/pdfa/validate-pdftron.html
  http://ms25.no-ip.info/pdfa/validate-pdfbox.html

I also used the online validators

  http://www.validatepdfa.com/online.htm

and

  http://www.pdf-tools.com/pdf/validate-pdfa-online.aspx

Finally I asked Ross Moore to check my file with Acrobat Pro v.11.

Only PDFtron complained about an uncomplete CIDSet.

Regards,
  Reinhard

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Reinhard Kotucha                            Phone: +49-511-3373112
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