
Reference letter for a PhD candidate: Ing. Karel Zimmermann 
 
 
 
I have known K. Zimmermann since 2003, when he started his master’s thesis under my 
supervision. The master thesis proposed the so called class-specific extremal regions, a subset of 
extremal regions whose shape commonly occurs in images of objects from some class. Results of 
Karel’s MSc thesis were of a quality sufficient for publication at a good international conference 
and after showing interest in post-graduate study, he was accepted into the PhD programme. 
 
During his PhD, Karel confirmed his ability to perform high-quality research, already evident in the 
MSc thesis. He is well motivated, hard working, and independent. Naturally, he needed advice and 
guidance, but at the level of ideas, directions, priorities. It was very pleasant for the supervisor to 
see that once goals were set, one did not have to worry about Karel’s progress. In due course, Karel 
would bring the results back. As the PhD progressed, Karel was getting more and more 
independent, setting his own research goals.  
 
Karel submitted his thesis in about 3 and half years, which is, by CTU standards, very early. 
 
The quality of his results are demonstrated by the fact that a paper describing the core contribution 
of the thesis has been accepted to IEEE Transactions on Pattern Analysis and Machine Intelligence, 
the most prestigious journal in the field. 
 
In conclusion, I recommend K. Zimmermann’s thesis be accepted for defense. 
 
The letter has been shown to K. Zimmermann’s co-supervisor, T. Svoboda – and he concurs with 
my opinions. 
 
Doc. Dr. Ing. J. Matas, 
Supervisor 
 
In Prague, 
September 3, 2008