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Gentoo LinuxTag 2011 and static gallery generators

This year our booth was placed between openSUSE and Schillix. The booth was staffed by a mix of known and new faces: Alex Legler (a3li), Chí-Thanh Christopher Nguyễn (chithanh), Andrew Karpow, Attila Stehr, Christian Ruppert (idl0r), Stefan Behte (craig), Marcus Becker and myself (sping).

Running the booth meant setup, teardown, and four days of of listening, answering questions, offering free flyers, DVDs, posters, selling t-shirts and mugs. 200 DVDs were sponsored by the Gentoo Foundation, Inc. (thanks!), all gone.

100 posters were sponsored by Förderverein Gentoo e.V., all gone. 14 T-Shirts and 40 mugs were sold. Off the booth Chí-Thanh and Andrew were part of the team winning the hacking contest (just as the year before).

I have set up a gallery based on Cataract Gallery Generator joined by a sexy intro page by a3li at now. Please check it out for more Gentoo pictures of LinuxTag 2011 and previous exhibitions. If you have pictures for me to add, please pick a Creative Commons license and send a link my way.

The rest of this post is about the process of setting up the gallery. I originally started with mkgallery, also checked igal2, Photon and lazygal. mkgallery has little features and many hickups, igal2 turned out too boring (compared to the others) and doesn't seem to work recursively. Photon makes use of command-line GIMP, which was a no-go on our server to me. For lazygal we don't have dependency pyexiv2 in tree yet (I now found it in an overlay). However, the most convincing reason for Cataract was its demo gallery. So I wrote a quick ebuild for it (media-gfx/cataract in overlay betagarden), wrote a Python script to generate required index.xml files

and fixed one or two CSS issues manually. Among the problems that Cataract still has is respecting EXIF orientation hints. That is reported upstream by now, I hope for the best.

Update: There are now packages for pyexiv2, lazygal and photon in overlay betagarden: dev-python/pyexiv2, media-gfx/lazygal, media-gfx/photon.

The images on the left are licensed CC-BY-NC-SA/3.0 Alex Legler (images 1 and 3) and CC-BY-NC-SA Jonathan Wonneberger (images 2 and 4).

Poster "Gentoo Abducted"

Back in 2004 Matteo "Peach" Pescarin did a poster edit of his "Gentoo Abducted" wallpaper.

The poster is portrait format and shows a city in background, instead of countryside, if you look close. He has now re-released its SVG sources.

With these sources the Förderverein Gentoo e.V. is able to offer a limited number of FREE A1 poster prints at LinuxTag Berlin next week. Please drop by to get your copy.

The posters were printed from a 3521x4978 TIFF file, which is A1 plus 1mm overlap everywhere at 150dpi, making a 50MB upload after removal of the alpha channel. Flyeralarm has done a great job on print with regard to all of quality, time, price, and service.

UPDATE : We have run out of posters on the fourth (and last) day of LinuxTag. 100 posters it was.

Gamma-correct image scaling

I recently heard of Eric Brasseur's article Gamma error in picture scaling. The news that many graphics tools including the GIMP hurt certain colors during image scaling was rather surprising to me. I was actually looking a command line tool to that job right out of the box — any recommendations besides ImageMagick/convert or netpbm/pamscale? — but I ended up writing a pygimp-based GIMP plugin yesterday. It does the job and comes with a simple GUI. Compared to core GIMP, the speed is quite disappointing though, probably because of using Python (and an extra layer) but C code.

Once you have the plugin installed

# sudo layman -a betagarden
# sudo emerge -av media-plugins/gimp-imagescaler

you should find an item "Scale Image with correct Gamma..." at the bottom of the "Image" menu.

The code is free software, clean patches are welcome:

On saving gamma

When saving an image as PNG in GIMP you are facing the choice of checking option save gamma or not. When you check it — according to official GIMP documentation — the gamma value of your display environment is embedded into the PNG file. I was resizing the Gentoo logo, file gblend.png. Checking save gamma on export results in the left (correct) image, leaving it unchecked in the right: too far towards purple.

If you use Firefox or Thunderbird these two images look different. To my recent surprise they look identical in all of GWenview 4.6.2, gthumb 2.12.3 and Thunar 1.2.1. Interestingly, now that I have seen the difference I notice that the logo shown on does not have correct gamma. See for yourself. I have contacted its operator about it, let's see what happens. I don't really have time to inspect this issue much further. If you do that would be awesome. Please send patches to upstream for me. Thank you!

EDIT : Mike has updated the logo on by now.

Linking to

Before I fully arrived at GNU/Linux I thought that Acrobat Reader would be one of those things that would be hard to miss. As there is a Linux version I would not even have to live without it, but even better: there's quite a few good alternatives that are true free software. At some point I started using KPDF of KDE and moved on to its sucessor Okular at some point. Even after switching from KDE to XFCE I still kept using Okular (besides a few other strong KDE tools: Konversation, Gwenview, KSnapshot, Yakuake, K3b). I have finally added a link to to the link section of this blog (on the right, a bit down). When googling for "pdf reader" is showing on the first page already, 9th place. It would rock, if we get it to the top and I'm optimistic that one day it will make it. Please link to on your site, too. Your link can change something.

(German) Samstag 26.03.2011 Anti-Atom-Demo!

Ich bin spät dran, aber das Thema ist trotzdem wichtig. Das Atomkraftwerke mehr als nur ein "Restrisiko" sind, müssen in diesen Tagen in Japan viele Tausend Menschen am eigenen Leib erfahren. Hier bei uns sieht das trotz weniger Erdbebengefahr nicht viel anders aus: Kritiker gehen davon aus, dass zum Beispiel keines unserer Kraftwerke einen Anschlage à la Nine-Eleven überstehen würde. Mich persönlich haben in den vergangenen Tagen hauptsächlich zwei Video-Reportagen wachgerüttelt:

Wer noch extra Motivation braucht: Die Band "Wir sind Helden" spielt im Anschluss (siehe Ablauf) live, die kennt sicher der ein oder andere... In Berlin beginnt die eigentliche Demo 11:00 auf dem Potsdamer Platz, losgelaufen wird um 12:00, siehe Ablauf. Ich bin dabei.

(German) Video-Reportage "Geheimer Prüfkatalog - Alle AKW vor dem Aus?"

Zum Video hier: Geheimer Prüfkatalog - Alle AKW vor dem Aus? Auch das angesprochene geleakte Dokument "Erste Überlegungen zu Konsequenzen Fokushima" findest sich dort zum Download. Ein bisschen Hoffnung habe ich, es könnte funktionieren. Aber das wär schon irgendwie ein Wunder und so naiv kann ich dann offiziell wohl doch nicht sein. Spannend fand ich auch die Landkarte mit den Orten der Atomkraftwerke in Deutschland. Die hab ich mal ausgeschnitten.

Das ARD-Logo rechts oben ist dem Ausschnitt zum Opfer gefallen. Auch hier wieder Dank für den Post von