You are viewing a plain text version of this content. The canonical link for it is here.
Posted to fop-dev@xmlgraphics.apache.org by Jeremias Maerki <de...@jeremias-maerki.ch> on 2009/10/01 10:51:40 UTC

Re: [PDF] Entries in number tree not specified as indirect references

Hi Vincent,

good catch! Your observation is correct. That value must not be a direct
object.

I guess the reason Acrobat doesn't complain is that a PDF parser usually
doesn't really care whether a PDF object is direct or indirect as it is
handled transparently. Still, another implementation might rely on the
value being an indirect object.

On 29.09.2009 16:38:05 Vincent Hennebert wrote:
> Hi,
> 
> The StructTreeRoot dictionary must have a ParentTree entry whose type is
> a number tree. As explained in Section 3.8.5, “Number Trees” of the PDF
> Reference, Third Edition, the Nums entry of a number tree node must be
> an array of key-value pairs where value is an indirect reference to the
> object associated with the key.
> 
> This is not what is done in the current implementation of Logical
> Structure in FOP (Temp_Accessibility branch). The value (an array) is
> directly stored in the array of key-value pairs instead of being
> referenced. So technically the PDF produced is invalid. Acrobat doesn’t
> seem to complain, though.
> 
> Did I miss anything?
> Thanks,
> Vincent




Jeremias Maerki