PDF-PS

[Sebastien Pierre]

Hi folks!

I finally received the answer from xpdf's author:

<mail>
PDF has hyperlinks; but these can also be embedded as pdfmarks in
PostScript (ghostscript's ps2pdf, for example, will turn these into
hyperlinks in the PDF file).

PostScript is easier to generate than PDF (but you probably knew that
already).

PDF has some extra document structure support -- you can embed some
information about the structure of a document -- but I'm not very
familiar with this, so I don't know how useful it is (or will be).

PDF allows you to reuse images, e.g., if you have a logo image on
every page, the image data is only included once in the PDF file.
PostScript can do this with small images, but it's really hard to do
with large images.

As far as I know, color support is pretty much identical in PS and
PDF.  There's some obscure prepress support which may only be in PDF
and which I'm not all that familiar with (you'd have to ask someone
else for details on this).

One big advantage of PDF is that there are easy-to-use viewers for it
on Windows and MacOS platforms.  Most Win/Mac users don't have
ghostscript (though it is available).

Adobe is still maintaining PostScript; it's not going to go away
anytime soon.  But you're right that PDF is evolving more quickly.
Adobe is clearly pushing PDF pretty hard.

As I see it, here are your options:

1. Ditch the PDF backend, and embed as much info as you can
(hyperlinks) in the PS code as pdfmarks, so that ps2pdf will generate
good PDF files.

2. Ditch the PostScript backend - you can always convert PDF to PS if
you need to.  I'm guessing this would probably annoy a lot of people.

3. Two separate backends, as it is now.

4. Combine the PS and PDF backends.  There should be a lot of common
code here, if you do it right.  You could have a separate module that
generated PDF objects, the xref table, etc.

If I were doing something like this from scratch, I'd probably use
option 4.  But you have an existing PS backend, so it might be hard to
retrofit, I don't know.

- Derek
</mail>

So maybe it's not that useful now, because its seems like the PDF 
backend will be kept, but it's still interesting ;)

Cheers,
Sébastien.