Mats Sjöberg

Postdoctoral Researcher, D.Sc. (Tech.)
CBIR research group
Department of Computer Science, Aalto University Mats Sjöberg

Contact information

Room B326, 3rd floor of the Computer Science building,
Konemiehentie 2, Espoo, Finland
Postal Address:
Aalto University,
Department of Computer Science,
P.O.Box 15400,
FI-00076 Aalto,
Email: (GPG: 99E8E6D3) (permanent address, redirects to current work address)

Research interests

My research focuses on developing and applying machine learning methods for pattern recognition and analysis of big data. My primary interest is in visual data (images and video), including semantic understanding of visual content, predicting user perceptions (e.g., affect), and multimedia retrieval.

However, I have also worked with text data and very heterogeneous computer usage log data for proactive information retrieval of personal data.

In machine learning my main interests have been in neural networks (deep learning) and kernel methods.

Current topics

Earlier topics



I have instructed two Master's theses: Vladimir Goriachev and Ada-Maaria Hyvärinen, and one Bachelor's thesis: Yash Kasture. I'm currently instructing Julius Wang (doctoral student) and Arturs Polis (Master's student).




Pytorch-based image captioning framework used in our research group.

[Source code] - source code snapshot on GitHub (Apache 2.0 license).

Digital Me

The idea of the Digital Me (DiMe) server is to collect your personal data from various loggers into a central place that you control. The focus is on tracking knowledge work and developing applications that can help the knowledge worker manage their working life better.

[Source code] - the source code is freely licensed (MIT).
[Pre-print PDF] - Digital Me position paper presented at the Symbiotic 2016 workshop.

Pair annotation for multimedia

A web-based tool for performing pair-wise annotation of multimedia (videos or images), used in several MediaEval tasks. [Source code on GitHub].


Non-academic talks to a more general audience.

Selected publications

Full list of publications in the ACRIS database.

Google Scholar profile.

My ORCID is 0000-0002-3157-7668.

Doctoral thesis

From pixels to semantics: visual concept detection and its applications.
Department of Information and Computer Science, Aalto University School of Science.
[Available online]

Master's thesis

Content-based retrieval of hierarchical objects with PicSOM
Laboratory of Computer and Information Science, Helsinki University of Technology.
[Abstract PDF] [Entire document PDF].