PDF linearization (optimization)

[Eric Smith]

One of the items on my TODO list has been to make tumble support
PDF linearization (also known as optimization), which is intended to
make PDF files more suitable for online browsing with a web server.
Generating linearized PDF files on the fly (as tumble works) looks
*extremely* difficult, so I expected to either have to add an
additional pass or a separate program.

A while back I discovered that Ghostscript actually comes with a
PDF linearization program called pdfopt.  However, pdfopt as supplied
with Ghostscript 6.52 fails with various cryptic errors when used on
PDF files produced by tumble.  I was concerned that this might be
due to some problem with tumble; unfortunately I'm not aware of any
available PDF validation software or service.

Yesterday I discovered that pdfopt from Ghostscript versions 7.05 and
7.07 seems to work fine with tumble output.  I'm somewhat curious as
to what change to pdfopt fixed the problem, and it's still possible that
there's something wrong with tumble output, but I don't have time
available now to research it.

I'm going to remove linearization from the tumble TODO list.