Martin Wuertele <[EMAIL PROTECTED]> wrote: > * Eduard Bloch <[EMAIL PROTECTED]> [2006-05-09 20:05]: > >> #include <hallo.h> >> * Yaroslav Halchenko [Tue, May 09 2006, 01:15:54PM]: >> > Dear Developers, >> > >> > I've raised this discussion at -mentors first [1] but I think it is worth >> > asking on a devel list since no definite decision was reached and I >> > could not find similar discussion in the archives. >> >> I am strongly against compressing PDFs if the compression ratio is >> miserable, which is IMO the case for most PDFs nowadays. Take our policy >> document for example - compression saves less than 30 percent and throws >> unneeded stowns in the way of potential readers. > > How about compressing all generated pdf with eg pdftk instead of gzip? > That would save on space without troubling potential readers.
Most PDF files in Debian are already compressed; at least those which are generated on a Debian system, and somehow TeX is involved are. [EMAIL PROTECTED]:~/area$ pdftk policy.pdf output policy.unc.pdf uncompress [EMAIL PROTECTED]:~/area$ pdftk policy.unc.pdf output policy.recomp.pdf compress [EMAIL PROTECTED]:~/area$ lh policy.* -rw-r--r-- 1 frank frank 657K 2006-05-09 21:18 policy.pdf -rw-r--r-- 1 frank frank 667K 2006-05-09 21:19 policy.recomp.pdf -rw-r--r-- 1 frank frank 1.4M 2006-05-09 21:19 policy.unc.pdf [EMAIL PROTECTED]:~/area$ lh /usr/share/doc/debian-policy/policy.pdf.gz -rw-r--r-- 1 root root 471K 2006-04-26 07:27 /usr/share/doc/debian-policy/policy.pdf.gz So somehow uncompressing-recompressing with pdftk gives a slightly larger file, whereas gzipping saves 28%. Or in other words, the original PDF ZIP compression saves 53% compared to the uncompressed PDF file, additional gzipping saves 67% all in all. And bzip2 on the uncompressed PDF file yields -rw-r--r-- 1 frank frank 332K 2006-05-09 21:19 policy.unc.pdf.bz2 or 76% space saving. To me, this sounds like in general it's not worth to compress compressed pdf files with gzip; if we'd go for size, we should use bzip2. However, we have to keep in mind that some -doc packages consist mainly of PDF files and would significantly increase in size (or need some additional splitting). Regards, Frank -- Frank Küster Single Molecule Spectroscopy, Protein Folding @ Inst. f. Biochemie, Univ. Zürich Debian Developer (teTeX)
