I think it's worth approaching upstream and recompressing the images in upstream.
Ondřej Surý On 26. 5. 2013, at 17:56, Adam Borowski <kilob...@angband.pl> wrote: > Hi folks! > > A while ago, someone raised the possibility of recompressing PNG files. > Unlike xz, this would save space not only on mirrors but also on live > installed systems. PNGs are nearly incompressible so this is mostly > independent from xz. > > At least by number, there's a lot of PNG images: > > zgrep -i '\.png ' Contents-*gz|wc -l > 577815 > zcat Contents-*gz|wc -l > 4296965 (including 3*35 lines of header) > > This massive number of files seems to be concentrated mostly in a limited > number of packages: > > 35276 widelands-data > 28827 libjs-mathjax > 22225 ns3-doc > 19968 jsmath-fonts > 13395 openclipart2-png > 13296 freefoam-dev-doc > 10271 w3-recs > 9877 uqm-content > 9643 wesnoth-1.11-data > 9015 wesnoth-1.10-data > 8120 openclipart-png > 6773 oxygen-icon-theme > 6546 lxde-icon-theme > 6272 mixxx-data > 5890 gnome-icon-theme > 5068 triplea > 4641 tuxfootball > 4505 gnome-themes-extras > 4180 gnome-colors-common > 3780 lilypond-doc > > Some time ago, I tested a number of png optimizers, and the best results, by > far, come from using "optipng -o4 -i0 -fix" then "advpng -z4". The former > attacks the payload well, then advpng (package advancecomp) has good deflate. > -o4 is there because higher optipng levels mess only with zlib arguments, > -i0 because advpng is afraid of interlaced files (why?), -fix because advpng > refuses to touch files with certain errors like cruft after the end, as > Adobe tools like to leave. > > I did test the alternatives quite thoroughly, but the corpus I needed that > for was quite specific. It's possible some other set of tools might be > better in general; these settings are the highest for optipng+advpng that > make sense, though. > > > So here are the results: > > size(MB) o o+a > widelands-data 105 95.1% 93.4% > libjs-mathjax 29 99.0% 98.5% > openclipart2-png 476 99.6% 99.4% > w3-recs 16 88.4% 84.2% > wesnoth-1.11-data 89 98.3% 98.1% > fonts-mathjax-extra 4 94.6% 90.0% > (sizes include .png images only, o is optipng, o+a optipng+advpng) > > Nothing stunning, I'm not sure if savings of this kind are worth a lot of > heed. I'd probably be good to have a common tool somewhere, to not reinvent > the wheel for every package. > > -- > ᛊᚨᚾᛁᛏᚣ᛫ᛁᛊ᛫ᚠᛟᚱ᛫ᚦᛖ᛫ᚹᛖᚨᚲ > > > -- > To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org > with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org > Archive: http://lists.debian.org/20130526155606.gb2...@angband.pl > -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/04a89d77-8284-49c3-9c82-0ec2afbba...@sury.org