Semantic Event Fusion of Different Visual Modality Concepts for Activity Recognition

Carlos F. Crispim-Junior*, Vincent Buso, Konstantinos Avgerinakis, Georgios Meditskos, Alexia Briassouli, Jenny Benois-Pineau, Ioannis Kompatsiaris, Francois Bremond

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

23 Citations (Web of Science)


Combining multimodal concept streams from heterogeneous sensors is a problem superficially explored for activity recognition. Most studies explore simple sensors in nearly perfect conditions, where temporal synchronization is guaranteed. Sophisticated fusion schemes adopt problem-specific graphical representations of events that are generally deeply linked with their training data and focused on a single sensor. This paper proposes a hybrid framework between knowledge-driven and probabilistic-driven methods for event representation and recognition. It separates semantic modeling from raw sensor data by using an intermediate semantic representation, namely concepts. It introduces an algorithm for sensor alignment that uses concept similarity as a surrogate for the inaccurate temporal information of real life scenarios. Finally, it proposes the combined use of an ontology language, to overcome the rigidity of previous approaches at model definition, and a probabilistic interpretation for ontological models, which equips the framework with a mechanism to handle noisy and ambiguous concept observations, an ability that most knowledge-driven methods lack. We evaluate our contributions in multimodal recordings of elderly people carrying out IADLs. Results demonstrated that the proposed framework outperforms baseline methods both in event recognition performance and in delimiting the temporal boundaries of event instances.

Original languageEnglish
Pages (from-to)1598-1611
Number of pages14
JournalIeee Transactions on Pattern Analysis and Machine Intelligence
Issue number8
Publication statusPublished - Aug 2016
Externally publishedYes


  • Knowledge representation formalism and methods
  • TIME
  • activity recognition
  • concept synchronization
  • multimedia perceptual system
  • uncertainty and probabilistic reasoning
  • vision and scene understanding

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