97,567 research outputs found
Detecting Low Rapport During Natural Interactions in Small Groups from Non-Verbal Behaviour
Rapport, the close and harmonious relationship in which interaction partners
are "in sync" with each other, was shown to result in smoother social
interactions, improved collaboration, and improved interpersonal outcomes. In
this work, we are first to investigate automatic prediction of low rapport
during natural interactions within small groups. This task is challenging given
that rapport only manifests in subtle non-verbal signals that are, in addition,
subject to influences of group dynamics as well as inter-personal
idiosyncrasies. We record videos of unscripted discussions of three to four
people using a multi-view camera system and microphones. We analyse a rich set
of non-verbal signals for rapport detection, namely facial expressions, hand
motion, gaze, speaker turns, and speech prosody. Using facial features, we can
detect low rapport with an average precision of 0.7 (chance level at 0.25),
while incorporating prior knowledge of participants' personalities can even
achieve early prediction without a drop in performance. We further provide a
detailed analysis of different feature sets and the amount of information
contained in different temporal segments of the interactions.Comment: 12 pages, 6 figure
Pedestrian Attribute Recognition: A Survey
Recognizing pedestrian attributes is an important task in computer vision
community due to it plays an important role in video surveillance. Many
algorithms has been proposed to handle this task. The goal of this paper is to
review existing works using traditional methods or based on deep learning
networks. Firstly, we introduce the background of pedestrian attributes
recognition (PAR, for short), including the fundamental concepts of pedestrian
attributes and corresponding challenges. Secondly, we introduce existing
benchmarks, including popular datasets and evaluation criterion. Thirdly, we
analyse the concept of multi-task learning and multi-label learning, and also
explain the relations between these two learning algorithms and pedestrian
attribute recognition. We also review some popular network architectures which
have widely applied in the deep learning community. Fourthly, we analyse
popular solutions for this task, such as attributes group, part-based,
\emph{etc}. Fifthly, we shown some applications which takes pedestrian
attributes into consideration and achieve better performance. Finally, we
summarized this paper and give several possible research directions for
pedestrian attributes recognition. The project page of this paper can be found
from the following website:
\url{https://sites.google.com/view/ahu-pedestrianattributes/}.Comment: Check our project page for High Resolution version of this survey:
https://sites.google.com/view/ahu-pedestrianattributes
Second-order Temporal Pooling for Action Recognition
Deep learning models for video-based action recognition usually generate
features for short clips (consisting of a few frames); such clip-level features
are aggregated to video-level representations by computing statistics on these
features. Typically zero-th (max) or the first-order (average) statistics are
used. In this paper, we explore the benefits of using second-order statistics.
Specifically, we propose a novel end-to-end learnable feature aggregation
scheme, dubbed temporal correlation pooling that generates an action descriptor
for a video sequence by capturing the similarities between the temporal
evolution of clip-level CNN features computed across the video. Such a
descriptor, while being computationally cheap, also naturally encodes the
co-activations of multiple CNN features, thereby providing a richer
characterization of actions than their first-order counterparts. We also
propose higher-order extensions of this scheme by computing correlations after
embedding the CNN features in a reproducing kernel Hilbert space. We provide
experiments on benchmark datasets such as HMDB-51 and UCF-101, fine-grained
datasets such as MPII Cooking activities and JHMDB, as well as the recent
Kinetics-600. Our results demonstrate the advantages of higher-order pooling
schemes that when combined with hand-crafted features (as is standard practice)
achieves state-of-the-art accuracy.Comment: Accepted in the International Journal of Computer Vision (IJCV
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