Re: PS vs. PDF

[Greg A. Woods]

[ On Tuesday, May 15, 2001 at 14:30:25 (+0100), address@hidden wrote: ]
> Subject: PS vs. PDF
>
> There seem to be cumbersome ways 
> of bundling fonts into PS but that does not seem particularly 
> straightforward, indeed isn't the cleanest way to bundle fonts 
> with postscript, PDF?

What's hard about bundling fonts in your PS document?  It doesn't seem
particularly difficult to me, though by following the proper PS DSC it's
not very hard to allow the font manipulation and inclusion to be held
off until the document is presented to the final output device (at which
time one might hope to actually know which fonts the device is already
loaded with!).

> If people were expected to have 
> choice in compression, then readers would be expected to install 
> 19384 decompressors.

That just does not compute!  There are very few commonly used formats
and some programs can even handle them all.  When using generic
compression though the sender has the responsibility of learning what
tools the intended recipient(s) might be most likely to have before
choosing a compression tool.

> Advances in compression tech are rare enough 
> so that making a choice seems a good compromise.

Generic compression techniques are always a compromise.  I don't know if
the dictionary used in PDF compression has been pre-tuned, or not, but I
suspect it has (it should be!).

> You can 
> still turn a PDF file into an uncompressed PDF file and edit 
> the postscript code to fix it if you like to do that.

I know it should be possible, but ps2pdf (i.e. GhostScript) doesn't seem
capable of this, and it sure as heck can't be done with any generic file
decompression tool I know of.  Yes, GS can convert some PDF files into
raw, real, PostScript, but not always, and not always correctly.
Acrobat seems to have the same limitations, but with a different set of
PDFs.  These problems may relate directly to the fact that there have
been at least three major variants of PDFs.  I've never had so many
compatability problems with raw PS (unless I'm trying to manipulate it
using the DSC comments, of which there are also at least three major
releases, but over more years).

(That's not to say that Lout's current PDF output is unusable with
either GS or Acrobat -- I think it does actually work fine with both.)

-- 
                                                        Greg A. Woods

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