Worling professionally w/ PDF I can say that Adobe does not hide
anything, and the little parts that are not fully documented are easy
to find.
Not true. The format is open and documented, yes, but there are a some
specialities that aren't documented and perhaps will not before someone
hacks them (like the Type1 encryption at that time).
I mean esp. the Adobe Reader Extensions activation - to enable the
commenting of PDFs and saving of form contents also in Adobe Reader,
you *must* use Acrobat 7 (or that older expensive server), and it's
not even possible to access these functions via Acrobat's API.
The feature as such may be documented, but not in a way that anybody could re-build it.
There are many PDF libs out there, and even Adobe's own lib is not the
best... strange as this might sound...
too true; and it was sometimes hard to work around the errors in Adobe's libs (e.g. some JavaScript stuff in Acrobat <5).
pdf is open format, but Adobe keeps adding closed features to it
Well, the answer is NO, that is not the case!
see above
And naturally there are a lot documented features that only Adobe's lib provide - they publish the specs only after they implemented the features themselves. (I've no problem with that, it's their right as the developers, and they live by being a step ahead.)
In printing rendering/converting into a bitmap format (usually tiff)
is called ripping.
PDF is not a bitmap format. See below.
There are basically 3 big RIPs out there ... all other's are more or
less based on them: Adobe, Ghostscript and Jaws...
Simplified, a RIP has two levels:
- the PostScript interpreter that writes intermediate vector data
- and the rasterizer that makes the bitmaps from it.
You can look at Distiller (or another PDF machine) as the first level of a full RIP, in this case the 'intermediate' format is what you want: PDF
You can look at Reader (or any other PDF viewer) as the second level of a RIP, it calculates a bitmap (preview) of the PDF data.
There are some more important RIP engines than those that you mentioned, e.g. Harlequin, Jaws' big brother. That's really a base for a lot of other RIPs.
And there are even some other PDF machines out there that aren't 'big names', e.g. PStill by Frank Siegert
Best regards,
Henning Hraban Ramm
Südkurier Medienhaus / MediaPro
Support/Admin/Development Dept.