111,980 research outputs found
Discriminatively Trained Latent Ordinal Model for Video Classification
We study the problem of video classification for facial analysis and human
action recognition. We propose a novel weakly supervised learning method that
models the video as a sequence of automatically mined, discriminative
sub-events (eg. onset and offset phase for "smile", running and jumping for
"highjump"). The proposed model is inspired by the recent works on Multiple
Instance Learning and latent SVM/HCRF -- it extends such frameworks to model
the ordinal aspect in the videos, approximately. We obtain consistent
improvements over relevant competitive baselines on four challenging and
publicly available video based facial analysis datasets for prediction of
expression, clinical pain and intent in dyadic conversations and on three
challenging human action datasets. We also validate the method with qualitative
results and show that they largely support the intuitions behind the method.Comment: Paper accepted in IEEE TPAMI. arXiv admin note: substantial text
overlap with arXiv:1604.0150
Newtonian Image Understanding: Unfolding the Dynamics of Objects in Static Images
In this paper, we study the challenging problem of predicting the dynamics of
objects in static images. Given a query object in an image, our goal is to
provide a physical understanding of the object in terms of the forces acting
upon it and its long term motion as response to those forces. Direct and
explicit estimation of the forces and the motion of objects from a single image
is extremely challenging. We define intermediate physical abstractions called
Newtonian scenarios and introduce Newtonian Neural Network () that learns
to map a single image to a state in a Newtonian scenario. Our experimental
evaluations show that our method can reliably predict dynamics of a query
object from a single image. In addition, our approach can provide physical
reasoning that supports the predicted dynamics in terms of velocity and force
vectors. To spur research in this direction we compiled Visual Newtonian
Dynamics (VIND) dataset that includes 6806 videos aligned with Newtonian
scenarios represented using game engines, and 4516 still images with their
ground truth dynamics
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