Oct 16

Sometimes (e.g. newspaper or compressing images) we have to reduce depth of our image to only 1 bit. We can do it simply by applying thresholding:

But the result is usually not satisfactory for us – it has large regions of the same color.
There is a better idea than thresholding when it comes to monochromatic images:

1. Take original image:

2. Apply gaussian noise:

3. Do thresholding:

After this procedure we have an image that creates illusion that it has more than 1 bit depth. It’s so called dithering.
I’ve found this idea in “Practical signal processing” written by Mark Owen.


Oct 16

I want to present 3 algorithms of computing Fibonacci numbers written in Haskell: exponential, linear and logarithmic.

Read More


Aug 21


Jul 13

1. When I use nautilus I’d like to type addresses by hand. In several Gnome themes this option is disabled. You can fix it:

  • Launch gconf-editor
  • Go to apps/nautilus/preferences
  • Check always_use_location_entry

2. After updating Firestarter stops displaying information about blocked connections.
In order to fix:

  • Open /etc/rsyslog.d/50-default.conf
  • Uncomment there:

    #*.=info;*.=notice;*.=warn;\
    # auth,authpriv.none;\
    # cron,daemon.none;\
    # mail,news.none -/var/log/messages

  • Type sudo service rsyslog restart

3. In Gnome Unity some tray icons (like Firefox, QuickSynergy or Kadu) are not diplayed.
Type:

gsettings set com.canonical.Unity.Panel systray-whitelist "['all']"
unity --replace

Jul 13