[luatex] \pdfcompresslevel (was: Luatex 0.42.0 (a snapshot release))

Heiko Oberdiek oberdiek at uni-freiburg.de
Fri Jul 17 14:11:37 CEST 2009

Hello Taco,

On Fri, Jul 17, 2009 at 01:18:41PM +0200, Taco Hoekwater wrote:

> Heiko Oberdiek wrote:
> >On Fri, Jul 17, 2009 at 12:31:56PM +0200, Taco Hoekwater wrote:
> >
> >>* The \pdfcompresslevel is now effectively fixed as soon as
> >>  output to the pdf file has occurred.
> >
> >Why? Is there a technical reason?
> Yes (-ish). The compression level is now a part of the pdf back-end
> structure because with that, the back-end does not have to access
> eqtb all the time. It would be possible to do a synchronization
> whenever the value in eqtb changes, but:
> >Sometimes it makes sense to have some parts uncompressed
> >(e.g. for debugging purposes, ...)
> You could just be brave and not compress the pdf at all.

There can be Metadata Streams in the PDF file (e.g. in the Catalog).
The PDF specification says in "10.2.2 Metadata Streams":

| The contents of a metadata stream is the metadata represented in
| Extensible Markup Language (XML). This information is visible as plain
| text to tools that are not PDF-aware only if the metadata stream is both
| unfiltered and unencrypted.

How can the compression of these streams can be avoided without
having umcompressed anything else?

Yours sincerely
  Heiko <oberdiek at uni-freiburg.de>

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