41,254 research outputs found
Forecasting Hands and Objects in Future Frames
This paper presents an approach to forecast future presence and location of
human hands and objects. Given an image frame, the goal is to predict what
objects will appear in the future frame (e.g., 5 seconds later) and where they
will be located at, even when they are not visible in the current frame. The
key idea is that (1) an intermediate representation of a convolutional object
recognition model abstracts scene information in its frame and that (2) we can
predict (i.e., regress) such representations corresponding to the future frames
based on that of the current frame. We design a new two-stream convolutional
neural network (CNN) architecture for videos by extending the state-of-the-art
convolutional object detection network, and present a new fully convolutional
regression network for predicting future scene representations. Our experiments
confirm that combining the regressed future representation with our detection
network allows reliable estimation of future hands and objects in videos. We
obtain much higher accuracy compared to the state-of-the-art future object
presence forecast method on a public dataset
Multi-View Region Adaptive Multi-temporal DMM and RGB Action Recognition
Human action recognition remains an important yet challenging task. This work
proposes a novel action recognition system. It uses a novel Multiple View
Region Adaptive Multi-resolution in time Depth Motion Map (MV-RAMDMM)
formulation combined with appearance information. Multiple stream 3D
Convolutional Neural Networks (CNNs) are trained on the different views and
time resolutions of the region adaptive Depth Motion Maps. Multiple views are
synthesised to enhance the view invariance. The region adaptive weights, based
on localised motion, accentuate and differentiate parts of actions possessing
faster motion. Dedicated 3D CNN streams for multi-time resolution appearance
information (RGB) are also included. These help to identify and differentiate
between small object interactions. A pre-trained 3D-CNN is used here with
fine-tuning for each stream along with multiple class Support Vector Machines
(SVM)s. Average score fusion is used on the output. The developed approach is
capable of recognising both human action and human-object interaction. Three
public domain datasets including: MSR 3D Action,Northwestern UCLA multi-view
actions and MSR 3D daily activity are used to evaluate the proposed solution.
The experimental results demonstrate the robustness of this approach compared
with state-of-the-art algorithms.Comment: 14 pages, 6 figures, 13 tables. Submitte
Trespassing the Boundaries: Labeling Temporal Bounds for Object Interactions in Egocentric Video
Manual annotations of temporal bounds for object interactions (i.e. start and
end times) are typical training input to recognition, localization and
detection algorithms. For three publicly available egocentric datasets, we
uncover inconsistencies in ground truth temporal bounds within and across
annotators and datasets. We systematically assess the robustness of
state-of-the-art approaches to changes in labeled temporal bounds, for object
interaction recognition. As boundaries are trespassed, a drop of up to 10% is
observed for both Improved Dense Trajectories and Two-Stream Convolutional
Neural Network.
We demonstrate that such disagreement stems from a limited understanding of
the distinct phases of an action, and propose annotating based on the Rubicon
Boundaries, inspired by a similarly named cognitive model, for consistent
temporal bounds of object interactions. Evaluated on a public dataset, we
report a 4% increase in overall accuracy, and an increase in accuracy for 55%
of classes when Rubicon Boundaries are used for temporal annotations.Comment: ICCV 201
NTU RGB+D 120: A Large-Scale Benchmark for 3D Human Activity Understanding
Research on depth-based human activity analysis achieved outstanding
performance and demonstrated the effectiveness of 3D representation for action
recognition. The existing depth-based and RGB+D-based action recognition
benchmarks have a number of limitations, including the lack of large-scale
training samples, realistic number of distinct class categories, diversity in
camera views, varied environmental conditions, and variety of human subjects.
In this work, we introduce a large-scale dataset for RGB+D human action
recognition, which is collected from 106 distinct subjects and contains more
than 114 thousand video samples and 8 million frames. This dataset contains 120
different action classes including daily, mutual, and health-related
activities. We evaluate the performance of a series of existing 3D activity
analysis methods on this dataset, and show the advantage of applying deep
learning methods for 3D-based human action recognition. Furthermore, we
investigate a novel one-shot 3D activity recognition problem on our dataset,
and a simple yet effective Action-Part Semantic Relevance-aware (APSR)
framework is proposed for this task, which yields promising results for
recognition of the novel action classes. We believe the introduction of this
large-scale dataset will enable the community to apply, adapt, and develop
various data-hungry learning techniques for depth-based and RGB+D-based human
activity understanding. [The dataset is available at:
http://rose1.ntu.edu.sg/Datasets/actionRecognition.asp]Comment: IEEE Transactions on Pattern Analysis and Machine Intelligence
(TPAMI
Two-Stream RNN/CNN for Action Recognition in 3D Videos
The recognition of actions from video sequences has many applications in
health monitoring, assisted living, surveillance, and smart homes. Despite
advances in sensing, in particular related to 3D video, the methodologies to
process the data are still subject to research. We demonstrate superior results
by a system which combines recurrent neural networks with convolutional neural
networks in a voting approach. The gated-recurrent-unit-based neural networks
are particularly well-suited to distinguish actions based on long-term
information from optical tracking data; the 3D-CNNs focus more on detailed,
recent information from video data. The resulting features are merged in an SVM
which then classifies the movement. In this architecture, our method improves
recognition rates of state-of-the-art methods by 14% on standard data sets.Comment: Published in 2017 IEEE/RSJ International Conference on Intelligent
Robots and Systems (IROS
Predicting Human Interaction via Relative Attention Model
Predicting human interaction is challenging as the on-going activity has to
be inferred based on a partially observed video. Essentially, a good algorithm
should effectively model the mutual influence between the two interacting
subjects. Also, only a small region in the scene is discriminative for
identifying the on-going interaction. In this work, we propose a relative
attention model to explicitly address these difficulties. Built on a
tri-coupled deep recurrent structure representing both interacting subjects and
global interaction status, the proposed network collects spatio-temporal
information from each subject, rectified with global interaction information,
yielding effective interaction representation. Moreover, the proposed network
also unifies an attention module to assign higher importance to the regions
which are relevant to the on-going action. Extensive experiments have been
conducted on two public datasets, and the results demonstrate that the proposed
relative attention network successfully predicts informative regions between
interacting subjects, which in turn yields superior human interaction
prediction accuracy.Comment: To appear in IJCAI 201
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