Speaker: Asst. Prof. Nazlı İkizler Çinbiş, Hacettepe University

Topic: "Recognition of Human Interactions and Collective Activities"

Location: Middle East Technical University, Ankara, Turkey

Abstract: In this talk, I will give an overview about the recent algorithms that we have been working on at the Hacettepe Computer Vision Lab regarding human activity understanding. First, I will introduce "Histogram of Sequences", a video representation that aims at effective recognition of human interactions. This method basically combines the power of discriminative sequence mining and histogram representation, by mining sequences of the visual features that occur consequently in space and time. As an extension to base model, we incorporate a hierarchical temporal pyramid mechanisation, where the height of the temporal pyramid determines the temporal scales of the sequences. This new representation is likely to cover more complex spatiotemporal relationships such that the temporal variability of local sequences can be more accurately modelled. In the second part of my talk, I will present our work on collective activity recognition that analyses the behaviour of groups of people in videos. In this context, I will introduce "region-based multi-stream convolutional neural networks", where we extend the successful two-stream convolutional neural network architecture to handle multiple regions of interest in conjunction with the regular RGB and optical flow streams. In this context, we explore several ways of fusing multiple spatial and temporal streams so that the accuracy of recognition can be improved.

Bio: Dr. Nazlı İkizler Cinbiş received her BSc and MSc degrees from Department of Computer Engineering at Bilkent University. During 2005-2006, she was a visiting scholar at University of Illinois at Urbana-Champaign (UIUC). After receiving her PhD degree from Bilkent University in 2008, she worked as a post-doctoral research associate at Boston University (USA). Since 2011, she works as an Assistant Professor at Hacettepe University Department of Computer Engineering. She is amongst the founders of the Hacettepe University Computer Vision Laboratory (HUCVL). She is an associate editor of the IET Computer Vision journal since 2016 and has served as an area chair for CVPR 2018. Her research areas are mainly computer vision and machine learning, specifically focusing on video processing, human action and interaction recognition in images and videos and zero-shot learning. For more information, please visit

  Date and Time




  • Ankara, Ankara
  • Turkey



Asst. Prof. Nazli Ikizler Cinbis


Recognition of Human Interactions and Collective Activities