[scribus-dev] Fwd: Great meeting you in Saarbrücken

[Tamir Hassan]

Hi Leonard, hi all,

On 6/7/19 5:03 AM, Leonard Rosenthol wrote:
> I do indeed, Tamir -= great to see you continuing to work on this.
> 
> Certainly interested in hearing what you think you'd like to achieve and then trying to make it so...

For the benefit of everyone else on this list, when Leonard and I spoke 
at PDF Days 2018 in Berlin, I proposed the idea of extending the PDF 
spec to support the embedding of sufficient metadata that would make it 
possible to edit the document in some sort of "standardized" way. We 
would then finally have a way to exchange editable documents with others 
with robust layout and the other features of PDF - no other format 
offers this.

Obviously, most applications have their own proprietary format and their 
own internal models of the document structure. But there are very many 
similarities among the various canvas-based document formats and, just 
like PDF is a common standard for final form documents now, wouldn't it 
be great if there were a common standard for editable documents too?

There has been some previous work in this area. I've been told that 
Adobe Illustrator's Interchange PostScript, one of PDF's forerunners, 
was an attempt at a platform-independent, editable format. And PDF today 
at least supports tagging, which provides for standardized markup of 
logical structure elements. However, in order for a document to be 
editable, you need not only the logical structure, but also the 
stylesheet and/or layout rules. OpenOffice has also had the option to 
generate "hybrid PDFs" since around 2008 or so, which contain the ODF 
source in one of the content streams, but the robustness is lost when 
the document is opened for editing.

I have a lot of experience with automatic text typesetting, and this is 
where I see the biggest challenges in engineering a robust, yet editable 
document format, as there are often small, microtypographic differences 
between how different programs set text. But there is also a lot of 
inherent flexibility in setting text (see Hassan and Hunter 2015, linked 
below), and as long as the positions of the line breaks are stored in 
the PDF, it should be possible to re-set the text for editing using a 
different algorithm that maintains the line breaks and avoids major 
changes in layout.

Of course, when substantial edits to the text are made, text will have 
to reflow, which it should do in a predictable way according to a 
standardized layout model made up e.g. of either linked frames (typical 
DTP model) or X-Y page divisions (typical WP model).

PDF has long been under threat from Web standards, but I would hate to 
lose the robustness and archivability of PDF when HTML finally replaces 
it. This is why this idea is more about bringing the two worlds closer 
together, marking up the content in a similar way to HTML, styling it 
with CSS or similar, but encoding additional information about e.g. line 
breaks to ensure layout robustness and typographic fidelity.

At DocEng 2018 I published a paper on this topic and also coded up a 
basic prototype to illustrate the concept (see links below). But there 
is still a lot of work to be done and it would be great to have the 
cooperation and input of the various stakeholders in defining the format.

During the discussions at Libre Graphics, it was suggested that, if we 
could get Scribus, Inkscape and Libre Office to agree on a common model, 
then this would be a great first step that could get things going.

So this is why I am posting here, to see if this idea can gain traction 
and discuss the next steps. Perhaps now would be a good time to revisit 
the concept of Interchange PostScript in the light of how web standards 
have changed in the meantime.

Further reading: https://editablepdf.org
For references, see https://editablepdf.org/references/

Best,
Tamir


-- 
Dr. Tamir Hassan
Round-Trip PDF Solutions
Research, development and consulting for the generation, analysis and 
data extraction from PDF documents

Zirkusgasse 31, 1020 Wien, Austria
www.roundtrippdf.com
tamir at tamirhassan.com
+43 676 721 6288