Pre-press

[Zdenek Wagner]

út 27. 9. 2022 v 11:20 odesílatel <karl at aspodata.se> napsal:
>
> Karl Hammar:
> > Zdeněk Wagner:
> > > čt 22. 9. 2022 v 17:17 odesílatel <karl at aspodata.se> napsal:
> > ...
> > > > Isn't it possible to do pre-press with PostScript ?
> > > Generally, PDF/X is required but anyway, do you know a tool which can
> > > check the font size, font embedding, line width, color space,
> > > resolution of bitmap images, black overprint and optionally convert
> > > the color spaces using ICC profiles in postscript?
> >
> > Ok, regarding line width I can go the route as outlined below which
> > is clearly batch oriented.
> >
> > I sure I can do the same for font size and probably the other
> > things also if and when I can understand the terminology you use.
> >
> > Since postscript is a programming language, I can add another
> > level of indirection, e.g.:
> ...
> [ debug.ps etc. ]
>
> I showed that you can without much problem extraxt information about
> PostScript files by adding some code to it. I guess there is a long
> way to make it solve the voiced pre-press problems, but:
>
> . is there any interest in this ?
> . should I just drop it ?
> . if there is interest, should I move the discussion to texhax ?
>
Yes, it will be helpful. I do not mind using close source commercial
SW but there is a lack of SW for Linux. Up to now pdffonts (from
poppler) can show whether the fonts in a PDF file are embedded.
ps2pdf13 from ghostscript solves the problem with transparencies and
embeds fonts using replacement. I need not be always what you wish but
it is not worse than commercial SW. Ghostscript can read not only PS
but also PDF hencd ps2pdf13 can downgrade PDF to 1.3 which is needed
by PDF/X. Nowadays you almost always need PDF/X thus I still think
that it is easier to solved in poppler, qpdf or similar library. There
are less features to patch because PDF is not a programming language.
It is possible to link these libraries with lcms hence the colorspace
problems can be solved more easily than by reimplementatin of lcms in
PS. The easiest thing to imlpement is the display of TrimBox and
BleedBox in the PDF viewers. Adobe Acrobat has such an option in its
config, the user selects whether these boxes should be marked
visually. A bit more difficult is the display of the separate CMYK
planes. In Adobe Acrobat a user can choose which planes should be
visible. It is useful when checking the proper setting of black
overprint.


> Regards,
> /Karl Hammar
>

Zdeněk Wagner
http://ttsm.icpf.cas.cz/team/wagner.shtml