Web optimised PDF

My wife edits a newsletter that is mostly distributed via e-mail and the web (but some volume is also printed black-and-white at an inexpensive print shop). After her Windoze machine died and she could no longer use PageMaker and Distiller, I convinced her to use Scribus on Linux, and apart from her occasionally cursing myself for this, things works fine (she likes the CVS version of Scribus much better than 1.2).

Being sent out via e-mail, the newsletter must be below ~ 1 MB, desirably even smaller. Since the Scribus options for minimizing the size (subsetting fonts and downsampling images) did not meet that requirement (I'd need to try again to give figures), I looked for a route to PostScript and back to PDF that would give better compression, and the following does a surprisingly good job:


 * 1) Export as PDF, embedding all fonts, no font subsetting, no image subsampling --> newsletter_scribus.pdf [~2.8 MB]
 * 2) Convert to PS using `pdftops -level3' (Acroread 7's PS export will not work) --> newsletter.ps [huge]
 * 3) Convert back to PDF using ghostscript (subsetting fonts, subsampling images; this must be ghostscript 8.x or later) --> newsletter_compact.pdf [~500 kB]

As you see, the resulting PDF is more than 5 times smaller.

And now for the mysterious part: The new PDF file is not only smaller, but it is nicer (for on-screen reading) in three aspects:


 * 1) In Acroread 7 (the buggy one, I don't have any other around for comparing) on Linux, the text appears not to be antialiased for the old PDF, but is perfectly so for the new one. Xpdf shows both fine (and identical as far as I can tell). Gv/ghostscript hangs while antialiasing the old file, but shows the new file fine.
 * 2) Text marking and searching in the old file works not too well in Acroread (with lots of gaps in marked text), and practically not at all in Xpdf. It works perfect for the new file in both applications.
 * 3) The picture is shown far too dark in Acroread for the old file, but fine for the new file. Xpdf once again shows identical results for both.

You can see Acroread's output of both files at http://www.capca.ucalgary.ca/~wdobler/tmp/Scribus/

Additional information

 * If anybody is willing to run the resulting file through a PDF checker, you can try the latest newsletter at http://www.calgarymulticulturalcentre.com/CC_January_2006.pdf