Archive for March, 2011

GNOME 3 Launch Party in Hamburg

Tuesday, March 29th, 2011

For the new GNOME-3 love we will have a release party in Hamburg, just as many places over Germany and the whole world!

If you want to join the fun, be in the Attraktor, the local hackerspace. The address is Mexikoring 21, 22999 Hamburg, Germany, Europe, Earth, Solarsystem. Find more detailed instruction on how to get there here. The party starts on Friday, 2011-04-08, at 18:00 and runs open end.

We have a page in the local wiki to describe the event and further planning will take place there: As for the program: We intend to have a small introductory talk to show off what new user experience GNOME-3 will bring to the people. Afterwards, we will distribute GNOME-3 images to be put on pendrives to be able try GNOME-3. Finally, we’ll sit around, have some beers and snacks and discuss about the new and shiny GNOME :-)

Besides the GNOME-3 images, we’ll have GNOME-3 goodies to give away! Thanks a lot to the GNOME Foundation making that possible! So show up early to claim your goodies!

So I expect you to be there :-)

“Schuelerbotendienst” auf Abzocktour in Hamburg

Saturday, March 19th, 2011

Gerade komm’ ich mit nem Kumpel aus der Innenstadt. Dort wurden wir von zwei jungen Menschen, die vielleicht gerade 20 waren, angesprochen, ob wir den “Schuelerbotendienst” kennen wuerden. Wir verneinten und es wurde uns erklaert, dass es sich um ein soziales Projekt handele, bei dem Hartz IV Kinder sich etwas dazu verdienen koennten, indem sie Zeitung austragen. Dazu muessten sie aber erst auf Zuverlassigkeit geprueft werden. Und dafuer braeuchten sie Freiwillige, die sich ein kostenloses Abo zuschicken lassen und die korrekte Lieferung bestaetigen wollen. Nach zwei Wochen (oder so) wuerde das Abo dann aufhoeren aber wenn man wollte, koenne man es verlaengern.

Es wirkte nicht direkt abwaegig. Und in der Tat war ich fast gewillt, mich darauf einzulassen. Aber auf der Strasse etwas unterschreiben wollte ich nicht. Ich wollte die zurueckrufen, sobald ich mich informiert habe. Aber der junge Mann konnte mir gar keine Nummer seines Schuelerbotendienstes geben. Sehr fishy. Also ging ich mit einem blanko Zettel nach Hause und studierte die Information. Die zu unterschreibende Botschaft hat weder den “Schuelerbotendienst” noch eine Kostenfreiheit erwaehnt. Im Gegenteil. Zwei Wochen lang solle man das Abo bekommen, aber ohne seine Bankdaten angeben zu muessen, lediglich auf Rechnung. Danach wuerde sich das Abo eben um ein Jahr (oder so) verlaengern.

Die Skepsis war also angebracht und die Masche mit dem sog. “Schuelerbotendienst” scheint auch nicht neu zu sein.

Die Abos, die die Betrueger an die Menschen bringen wollen, sind von dem VSR Verlag, der wohl schon laenger mit dubiosen Vertriebler zu kaempfen hat.

Also Augen auf und Sinne geschaerft bei einem komischen Verkaufsgespraech auf der Strasse. Sollte doch etwas unterschrieben worden sein, gleich die 14 Tage Widerspruchsfrist in Anspruch nehmen und etwaige Vertraege kuendigen.

Sifting through a lot of similar photos

Friday, March 11th, 2011

To keep the amount of photos in my photo library sane, I had to sift through many pictures and get rid of redundant ones. I defined redundancy as many pictures taken at the same time. Thus I had to pick one of the redundant pictures and delete the other ones.

My strategy so far was to use Nautilus and Eye of GNOME to spot pictures of the same group and delete all but the best one.

I realised that photos usually show the same picture if they were shot at the same time, i.e. many quick shots after another. I also realised that usually the best photograph was the biggest one in terms on bytes in JPEG format.

To automate the whole selection and deletion process, I hacked together a tiny script that stupidly groups files in a directory according to their mtime and deletes all but the biggest one.

Before deletion, it will show the pictures with eog and ask whether or not to delete the other pictures.

It worked quite well and helped to quickly weed out 15% of my pictures :-)

I played around with another method: Getting the difference of the histograms of the images, to compare the similarity. But as the pictures were shot with a different exposure, the histograms were quite different, too. Hence that didn’t work out very well. But I’ll leave it in, just for reference.

So if you happen to have a similar problem, feel free to grab the following script :-)

#!/usr/bin/env python
import collections
import math
import os
from os.path import join, getsize, getmtime
import operator
import subprocess
import sys
subprocess.Popen.__enter__ = lambda self: self
subprocess.Popen.__exit__ = lambda self, type, value, traceback: self.kill()
directory = '.'
GET_RMS = False
mtimes = collections.defaultdict(list)
def get_picgroups_by_time(directory='.'):
	for root, dirs, files in os.walk(directory):
		for name in files:
			fname = join(root, name)
			mtime = getmtime(fname)
	# It's gotten a bit messy, but a OrderedDict is available in Python 3.1 hence this is the manually created ordered list.
	picgroups = [v for (k, v) in sorted([(k, v) for k, v in mtimes.iteritems() if len(v) >= THRESHOLD])]
	return picgroups
def get_picgroups(directory='.'):
	return get_picgroups_by_time()
picgroups = get_picgroups(directory)
print 'Got %d groups' % len(picgroups)
def get_max_and_picgroups(picgroups):
	for picgroup in picgroups:
		max_of_group = max(picgroup, key=lambda x: getsize(x))
		print picgroup
		print 'max: %s: %d' % (max_of_group, getsize(max_of_group))
		if GET_RMS:
			import PIL.Image
			last_pic = picgroup[0]
			for pic in picgroup[1:]:
				image1 =
				image2 =
				rms = math.sqrt(reduce(operator.add, map(lambda a,b: (a-b)**2, image1, image2))/len(image1))
				print 'RMS %s %s: %s' % (last_pic, pic, rms)
			last_pic = pic
		yield (max_of_group, picgroup)
max_and_picgroups = get_max_and_picgroups(picgroups)
def decide(prompt, decisions):
	import termios, fcntl, sys, os, select
	fd = sys.stdin.fileno()
	oldterm = termios.tcgetattr(fd)
	newattr = oldterm[:]
	newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
	termios.tcsetattr(fd, termios.TCSANOW, newattr)
	oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
	fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)
	print prompt
	decided = None
		while not decided:
			r, w, e =[fd], [], [])
			if r:
				c =
				print "Got character", repr(c)
				decision_made = decisions.get(c, None)
				if decision_made:
					decided = True
	    termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
	    fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)
for max_of_group, picgroup in max_and_picgroups:
	cmd = ['eog', '-n'] + picgroup
	print 'Showing %s' % ', '.join(picgroup)
	def delete_others():
		to_delete = picgroup[:]
		print 'deleting %s' % ', '.join (to_delete)
		[os.unlink(f) for f in to_delete]
	with subprocess.Popen(cmd) as p:
		decide('%s is max, delete others?' % max_of_group, {'y': delete_others, 'n': lambda: ''})