[luatex] [Dev-luatex] Luatex 0.42.0 (a snapshot release)

Peter Rolf indiego at gmx.net
Fri Jul 17 14:32:57 CEST 2009

Taco Hoekwater schrieb:
> 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, ...)
There are also some practical reasons to change the compression level at 
runtime. In general compression should be activated for a minimal file 
size. But it is recommended to disable compression for

- XMP metadata (for compatibility with external applications; think 
about indexing)
- embedded ICC-profiles (same reason as XMP data)

I use exactly these settings to produce PDF/X-4p compatible vector 
graphics. With a fixed compression it is no longer possible for me, to 
make them small sized. So you get the idea why I think that a fixed 
compression is no progress but a step back.
Maybe external pdf compressors can do the job in a compatible way 
(haven't tested). All I know is that Acrobats 'optimized' PDF are much 
bigger than the original ones.

> You could just be brave and not compress the pdf at all.
Not really an option for me.

Best wishes,  Peter

> Best wishes,
> Taco

More information about the luatex mailing list