Unfortunate for all those who have to exchange euro for Swedish krona: the krona has reached a 12-year high against the euro in August 2012. This is a rough 10% loss compared to last year.

Looking for a light-weight, space-efficient backup solution for your data on local machines and remote servers? Give rsnapshot a try: relying on existing toolchains, opting for convention over configuration, and simple customization for slightly trickier backup tasks.

Every Tuesday one can hear random shouting at 10 pm in Lappis, a big housing estate near Stockholms universitet and KTH Stockholm.

Fearsome clone troopers are patrolling the campus! What is happening on the campus of KTH Royal Institute of Technology in Valhallavägen?

Tyresta National Park is merely an hour away from Stockholm, and is mostly rocks, wood, water. A special feature is a large area that was flame-cut by a raging wildfire in 1999, now offering a rough and strange landscape.

Stockholm is said to have very clean water. Indeed, I can only agree. Clean, refreshing, and open to everyone: swimming in Stockholm’s waters is excellent. What a welcome contrast to the lukewarm dirty waters around Hong Kong.

Travelling from Munich to Stockholm by train seems to be a crazy idea at the very first glance. However, coming at a price of 39,- EUR and virtually no baggage limit, I chose to take a 21h train ride on me to Stockholm via Nürnberg, Hamburg and Copenhagen with Deutsche Bahn. While the crowded trains made the journey tougher than expected, I was surprised by getting a ferry-ride for both the Intercity Express and myself.

Wonder about the depths of C++? Wonder why the code you wrote yesterday no longer works in the morning? Olve Maudal stated on TNG Big Techday 5 in Munich that you ought to look under the hood when you want to understand more about C++. His key statements were: C++ is fast and powerful. Yet, a shark is always lurking in your back, so have an appropriate model in mind. I enjoyed the talk, for more about this, see Olve Maudal’s blog and the freely available slides on the topic.

How can we let a robot create a map of an unknown indoor environment using three cameras that simultaneously provide depth information and color images? We investigated this question in a four-week practical course at our university. This article sheds some light on the challenges involved.

The public parks in Shanghai attract lots of people, especially on Sundays. As described in a previous article, these parks offer plenty of opportunities for a variety of leisure activities. Actually, the People’s Park on People’s Square features the most curious of all the Sunday activities I have seen so far.

The city proper of Shanghai is home to 20 million inhabitants (see here and here). Unsurprisingly, despite of its density, the urban area goes on and on. Nevertheless, if people want to enjoy nearby green areas in their spare time, they have at least the public parks.

Taking the train is a common way of travelling in China and popular amongst locals and foreigners. Westerners might find some surprising facts about travelling in China by train.

Traffic in China follows other rules than in Germany. Also the assortment of vehicles in China is much more diverse; featuring trucks, buses, taxis, private cars, electric scooters, motorcycles, bicycles, three-wheeled cars and pedestrians all sharing the same space.

Tracking an object over a sequence of 2D images is a challenging task. One approach uses a linear mapping between observed intensity differences and target motion; this is presented in the paper Hyperplane Approximation for Template Matching by F, Jurie and M. Dhome. Here are some results from an implementation in Matlab by a fellow student and me.

Your wireless presenter is not working for prezi.com in full-screen mode? Here is how you might be able to fix the issue on X-based Linux desktops by temporarily remapping the “Page Up” and “Page Down” buttons of your keyboard.

A set of images that have some common overlapping regions can be stichted together to form a panorama picture. Some recent camera models can even compute the panorama picture internally and do not require post-processing on the computer. While this is a problem that has already been solved (for example, there is AutoStitch, here are some hints on classic DIY-panorama-stitching using Matlab, SIFT, DLT and RANSAC.

A well-known result from linear algebra is that one can use a matrix to represent any linear mapping between two vector spaces. While rotation is a linear mapping, translation unfortunately is not. But, wait… by adding another dimension to the vector space, and by interpreting the vector coordinates correctly, we are able to perform rotation and translation with a single matrix multiplication! This article describes how to restore a fragmented image with the help of homogeneous coordinates.

Motion blur usually occurs in an image, when the camera was moved with respect to the subject. Motion blur has an interesting effect on the Fourier-transformed image, as pointed out by D. Burschka at University of Technology, Munich. Here is an example how the Fourier-transformed images of toy images look like that have been subject to motion blur.

When using Gnome 3, one can access the dashboard by moving the cursor to the top-left corner of the screen. As it turns out, I always kept accidentally moving the cursor to this “hot corner”, thereby opening the dashboard involuntarily. Here is a small hack that disables this hot-corner effect. You are still able to show the dashboard by activating the “super” key.

Encrypting your hard drive is generally a good idea. Yet, the encryption renders dual-booting a little more difficult. Here I briefly sketch how I installed Ubuntu in parallel to an existing Arch installation on a LUKS-encrypted drive.

Being suprised by a low-flying unidentified objects? Maybe it was just a remote-controlled airplane by Team Black Sheep, who were giving a talk at TNG Big Techday in Munich on 2011-05-27.

Having a poisson-distributed random variable X, how can we efficiently generate samples (or say realizations) of that random variable? This article shows how Knuth’s technique can be derived and it also indicates that the Ratio-of-Uniforms method is quite efficient.

This article shows the derivation of an algorithm for resizing images in Matlab, using nearest-neighbor interpolation. Scaling an image is mathematically just multiplying image coordinates by a scaling factor. Surprisingly, when dealing with digital images, the scaling process becomes a little bit more complex.