Postscript involved when export PDFX1a from ID?

[Colorblind]

Is Postscript involved at all (such as background conversion from ID to ps to PDF) when doing an export as PDFX1a from InDesign CS4?

 

[WharfRat]

I would say not ... different language

MSD

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Is Postscript involved at all (such as background conversion from ID to ps to PDF) when doing an export as PDFX1a from InDesign CS4?

 

[Colorblind]

OK, thanks. Anyone else? Leonard, where are you when we need you

 

[meddington]

Might depend on what you mean by "involved", but as I understand it, PDF is largely based on postscript.

 

[Colorblind]

What I mean is this: when exporting as PDFX1a from InDesign CS4, does InDesign needs to translate the page to Postscript before generating the PDF? Is it different from saving as Postscript and distiling as PDFX1a besides the fact you don't see the actual Postscript file creation and Distiller interface? If so, what's different? Got this question from a designer and I truly didn't know what to answer.

 

[Al Ferrari]

My understanding of this is that InDesign has the ability to output the pdf code directly, without going through a postscript step.
I have gained this understanding from many posts by Dov Isaacs of Adobe at:

InDesign Macintosh - User to User Forums
and
InDesign Windows - User to User Forums

This is how InDesign is able to retain live transparency in the pdf, which would not be possible if it first went through a postscript step. The pdf format has an open specification, and there are many other applications besides InDesign that have this capability. Note that Quark by comparison does go through a postscript stage "in the background" when exporting a pdf. (Adobe Forums - InDesign PDF Exports not as small as Quark).

Adobe ceased further development of of postscript long ago with Level 3, and instead continues to develop the pdf format.

Al

 

[leonardr]

What I mean is this: when exporting as PDFX1a from InDesign CS4, does InDesign needs to translate the page to Postscript before generating the PDF?

No, it does not.

The beauty of direct export of PDF (whether from Adobe's application or others) is that the PDF is generated DIRECTLY from the graphical content of the editing application. No intermediate formats (such as Postscript) involved.

This means you get the highest fidelity PDF produced in the quicker manner.

Is it different from saving as Postscript and distiling as PDFX1a besides the fact you don't see the actual Postscript file creation and Distiller interface? If so, what's different?

Yes - VERY different in process.

However, since the output PDF is a PDF/X-1a, in this case - the fact that it went through Postscript vs. not doesn't matter. You have a PDF that complies with the appropriate international standard. Period!

 

[Colorblind]

That makes it crystal-clear now. Thank you Leonard!

 

[rich apollo]

Is there a difference in font handling between the two methods?

 

[leonardr]

Is there a difference in font handling between the two methods?

Yes, quite different - at least in terms of t he process.

With direct export we can go directly to the same font, installed in your OS, that you used to edit and have access to all of its information in order to write more complete information into the PDF. since we know it's a PDF - we make sure that both printing AND searching information is included in the font data.

When you go through Postscript, the font information has to be converted into Postscript-compatible font information (which is less complete than PDF font information) _AND_ since it's for printing (as far as the software knows) it doesn't have to include text searching information from the font, only stuff for printing. Therefore, you immediately lose LOTS of information. Distiller, therefore, has less information to work with when it constructs the PDF.

The same thing is true for other concepts such as color, for example. Postscript doesn't have a concept of color management and device-independent colors (eg. no ICC profiles, etc.) and so when you go through Postscript you are losing rich color information that is able to be maintained when working with direct export.

And then, of course, all the various things that aren't supported at all in Postscript - transparency, links, etc.

 

[Dov Isaacs]

No PostScript for Any InDesign Export or Illustrator/Photoshop Save

No PostScript for Any InDesign Export or Illustrator/Photoshop Save

To be very explicit, when you export PDF from InDesign or Save PDF from either Illustrator or Photoshop, there is absolutely no PostScript involved. The PDF is created via use of Adobe's PDF library by these applications.

PostScript would be very problematic for PDF creation from these applications primarily because their imaging model, common with PDF, is a significant superset of PostScript. PostScript's last language level, 3, was announced in 1996 and does not support layers, ICC color management, and transparency, to name the most prominent missing features. There are no plans to further update the PostScript language.

- Dov

 

[Dov Isaacs]

Is Postscript involved at all (such as background conversion from ID to ps to PDF) when doing an export as PDFX1a from InDesign CS4?

To further elaborate on the other responses in this thread, all PDF exported from InDesign, saved from Illustrator, and saved from Photoshop is done via direct creation of PDF by the application via Adobe's PDF Library. There are no intermediate steps involving creation and conversion of PostScript.

Why? Since 1999 and PDF 1.4 (Illustrator 9 and Acrobat 5), PDF has significantly eclipsed the PostScript imaging model. The PostScript language was last updated significantly when PostScript language level 3 was announced in 1996. PostScript does not support ICC color management, layers, and transparency. And there are no plans whatsoever to define a new PostScript language level. Thus, if you use PostScript to generate PDF, you have a lossy process.

- Dov

 

[michaelejahn]

PDFX-1a suffers from SPDFS - stop the transperencide !

PDFX-1a suffers from SPDFS - stop the transperencide !

To be very explicit, when you export PDF from InDesign or Save PDF from either Illustrator or Photoshop, there is absolutely no PostScript involved. The PDF is created via use of Adobe's PDF library by these applications.

PostScript would be very problematic for PDF creation from these applications primarily because their imaging model, common with PDF, is a significant superset of PostScript. PostScript's last language level, 3, was announced in 1996 and does not support layers, ICC color management, and transparency, to name the most prominent missing features. There are no plans to further update the PostScript language.

- Dov

Yes indeed ! The industry needs to take the next baby step AWAY from PDF/X1a - this was a short term goal, where we had many old RIPs trying to process objects that caused problems - we need to move on now.

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