Welcome to the home page of Praktische Informatik IV
Prof. em. Dr. Wolfgang Effelsberg (im Ruhestand)
Deputy: PD Dr. habil. Stephan Kopf

Research Overview

The Lehrstuhl für Praktische Informatik IV does research in the areas of Computer Networks and Multimedia Systems.

In Computer Networks we focus on wireless networks and sensor networks. For example, we were involved in a major German project investigating car-to-car-communication; here, we developed routing algorithms that allow communication directly between cars, using intermediate cars as relay stations, without a fixed infrastructure. This is especially challenging since the cars move quickly. Currently, we have also worked on indoor positioning algorithms for location-based systems, based on WLAN access points.

In Multimedia Systems we concentrated on algorithms for video analysis. We were among the first groups worldwide to develop text recognition algorithms for digital videos. Another topic of research was video abstraction where the system tries to automatically derive a short summary of a longer video. We have also worked on video repurposing. We designed new algorithms that map large-screen video to very small screens (e.g., on mobile phones) without losing relevant information. And we have designed and implemented an HDR (High Dynamic Range) video system. It takes multiple photos per video frame at different shutter speeds and composes them computationally into one optimally exposed frame, in real time. In the CamMark project we have developed a simulated video camcorder that can be taylored to the properties of a real camcorder and its recording context.

Academic Staff

The research group currently has two post-docs and two PhD candidates.


We do not teach at the Bachelor level anymore. At the Master level we offer advanced courses on Computer Graphics, Computer Games, a team project, and Master's Theses.

Offers for Students

We are always looking for good students for Master Theses. We also have job openings for students helping us in our research projects ("Hilfskräfte").

Links to websites

Course website for Master Students:


Grundzertifikat Beruf und Familie