Matti Pietikäinen on Suomen konenäön tutkimuksen pioneeri

Journey of a top researcher: Matti Pietikäinen is a pioneer in machine vision research in Finland

The founder of the Center for Machine Vision and Signal Analysis of the University of Oulu Emeritus Professor Matti Pietikäinen is one of the most established researchers of his field. A Highly Cited Researcher recognition is received for articles that rank in the top 1% by citations for the field in question.

Machine vision research pioneer Pietikäinen received the Highly Cited Researcher designation a year ago and another significant international recognition – the King-Sun Fu Prize. What was Matti Pietikäinen’s journey to becoming a Highly Cited Researcher like?


From Kiuruvesi to Maryland

The son of the Aittojärvi village merchant grew up with his older brother in Kiuruvesi while enjoying fishing, swimming and cross-country skiing as a typical boy living in the countryside. The gifted boy completed the first two classes of elementary school in one year even though, in his own words, he was lazy.

Secondary school and upper secondary school took young Matti to the Kiuruveden yhteislyseo, from which he graduated in 1968. Mathematical subjects were easy and to his liking.

-Two of my cousins had gone to the University of Oulu to study electrical engineering. I followed them on the same path, says Matti Pietikäinen.


After his graduation as a Master of Science in Engineering, Pietikäinen stayed at the Electrical Engineering Department to work as a laboratory engineer and started to work on his licentiate thesis. Pietikäinen got quite a boost to a career in research in the early 1980s, when he spent a little over a year at the University of Maryland in the United States.

The thesis advisor of his doctoral thesis on image texture analysis was Professor Azriel Rosenfeld, a hard-working, disciplined and productive scientist. The orthodox Jew professor, who published over 500 scientific articles, was also a doctor of religious science.

-Rosenfeld was able to write the manuscript of a scientific publication overnight after having received the results. I learnt the processes of science-making under his strict guidance, says Pietikäinen.


The researcher visit and internationalisation were important steps in Pietikäinen’s career, since there was no high-quality research being done in the field of image analysis in Finland in the 1980s.


Breakthrough with the machine vision method

After returning to Finland, Pietikäinen established his own research group, which was joined by young and enthusiastic researchers. The current professoriate of the University of Oulu includes several members of that research group. Olli Silvén, Juha Röning, Tapio Seppänen, Timo Ojala and Jaakko Sauvola started their research careers with Pietikäinen. Initially, the group had no funding. Cooperation with the industry helped them to make progress as, for example , the inspection of wood surfaces with the help of machine vision was an important research topic for the forest industry. Pietikäinen became an associate professor in computer engineering in 1986 and received a full  information technology professorship in 1991.

-The actual scientific breakthrough took place in 1996 and 2002 when we published the basic and generalised versions of the Local Binary Pattern method. Now, the LBP texture operator is one of the most referenced methods for pattern recognition, Pietikäinen says.


In 2004, the application of the LBP method in face recognition started. When Guoying Zhao joined the research group in 2005, the research progressed to the analysis of moving image and later to the analysis of facial expressions.

-Internationalisation of the group in the 2000s raised the level of our research. Now, 70–80% of the researchers at the Center for Machine Vision and Signal Analysis are foreigners, Pietikäinen says. During his career, he has been the thesis advisor for 31 doctoral theses.

-Our group has always known how to rejoice in the success of young people. It feels great when your doctoral candidate succeeds and gains a good position as a professor or in the industry.


Book project to start off retirement

Matti Pietikäinen retired in spring 2017, but he still attends international conferences as an invited speaker and participates in the operations of the research group. The biggest project to start off his retirement was, however, an easy-to-grasp book on AI challenges such as machine learning, machine vision and emotion AI Tekoälyn haasteet – koneoppimisesta ja konenäöstä tunnetekoälyyn (in Finnish) written by Pietikäinen in collaboration with Professor Olli Silvén.

-In a way, the book had to be done. I wanted to record the experience I gained during my 40-year career in AI and machine vision research and teaching. There was also a clear demand for the book: the debate around artificial intelligence is often exaggerated and false, and that is what we wanted to address in our book. A Finnish-language textbook and reference book is also needed to provide a realistic image of the possibilities of artificial intelligence.


The 70-year-olf emeritus professor intends to continue working on science part-time. Long walks, cross-country skiing and golf keep Matti Pietikäinen in good condition. He needs to stay in shape to keep up with his two lively young grandchildren when they visit their grandad.


Last updated: 11.12.2019