16,063 research outputs found
CamSwarm: Instantaneous Smartphone Camera Arrays for Collaborative Photography
Camera arrays (CamArrays) are widely used in commercial filming projects for
achieving special visual effects such as bullet time effect, but are very
expensive to set up. We propose CamSwarm, a low-cost and lightweight
alternative to professional CamArrays for consumer applications. It allows the
construction of a collaborative photography platform from multiple mobile
devices anywhere and anytime, enabling new capturing and editing experiences
that a single camera cannot provide. Our system allows easy team formation;
uses real-time visualization and feedback to guide camera positioning; provides
a mechanism for synchronized capturing; and finally allows the user to
efficiently browse and edit the captured imagery. Our user study suggests that
CamSwarm is easy to use; the provided real-time guidance is helpful; and the
full system achieves high quality results promising for non-professional use.
A demo video is provided at https://www.youtube.com/watch?v=LgkHcvcyTTM
PanoSwarm: Collaborative and Synchronized Multi-Device Panoramic Photography
Taking a picture has been traditionally a one-persons task. In this paper we
present a novel system that allows multiple mobile devices to work
collaboratively in a synchronized fashion to capture a panorama of a highly
dynamic scene, creating an entirely new photography experience that encourages
social interactions and teamwork. Our system contains two components: a client
app that runs on all participating devices, and a server program that monitors
and communicates with each device. In a capturing session, the server collects
in realtime the viewfinder images of all devices and stitches them on-the-fly
to create a panorama preview, which is then streamed to all devices as visual
guidance. The system also allows one camera to be the host and to send direct
visual instructions to others to guide camera adjustment. When ready, all
devices take pictures at the same time for panorama stitching. Our preliminary
study suggests that the proposed system can help users capture high quality
panoramas with an enjoyable teamwork experience.
A demo video of the system in action is provided at
http://youtu.be/PwQ6k_ZEQSs
Temporal Action Localization in Untrimmed Videos via Multi-stage CNNs
We address temporal action localization in untrimmed long videos. This is
important because videos in real applications are usually unconstrained and
contain multiple action instances plus video content of background scenes or
other activities. To address this challenging issue, we exploit the
effectiveness of deep networks in temporal action localization via three
segment-based 3D ConvNets: (1) a proposal network identifies candidate segments
in a long video that may contain actions; (2) a classification network learns
one-vs-all action classification model to serve as initialization for the
localization network; and (3) a localization network fine-tunes on the learned
classification network to localize each action instance. We propose a novel
loss function for the localization network to explicitly consider temporal
overlap and therefore achieve high temporal localization accuracy. Only the
proposal network and the localization network are used during prediction. On
two large-scale benchmarks, our approach achieves significantly superior
performances compared with other state-of-the-art systems: mAP increases from
1.7% to 7.4% on MEXaction2 and increases from 15.0% to 19.0% on THUMOS 2014,
when the overlap threshold for evaluation is set to 0.5.Comment: IEEE Conference on Computer Vision and Pattern Recognition (CVPR),
201
G2R Bound: A Generalization Bound for Supervised Learning from GAN-Synthetic Data
Performing supervised learning from the data synthesized by using Generative
Adversarial Networks (GANs), dubbed GAN-synthetic data, has two important
applications. First, GANs may generate more labeled training data, which may
help improve classification accuracy. Second, in scenarios where real data
cannot be released outside certain premises for privacy and/or security
reasons, using GAN- synthetic data to conduct training is a plausible
alternative. This paper proposes a generalization bound to guarantee the
generalization capability of a classifier learning from GAN-synthetic data.
This generalization bound helps developers gauge the generalization gap between
learning from synthetic data and testing on real data, and can therefore
provide the clues to improve the generalization capability
from Pure Leptonic Decays of with Radiative Corrections
The radiative corrections to the pure leptonic decay up-to one-loop order is presented. We find the virtual
photon loop corrections to is
negative and the corresponding branching ratio is larger than . Considering the possible experimental resolutions, our prediction of
the radiative decay is not so
large as others, and the best radiative channel to determine the or
is .Comment: 7 pages, 1 Latex file, 3 PS figure
Learning to Hash for Indexing Big Data - A Survey
The explosive growth in big data has attracted much attention in designing
efficient indexing and search methods recently. In many critical applications
such as large-scale search and pattern matching, finding the nearest neighbors
to a query is a fundamental research problem. However, the straightforward
solution using exhaustive comparison is infeasible due to the prohibitive
computational complexity and memory requirement. In response, Approximate
Nearest Neighbor (ANN) search based on hashing techniques has become popular
due to its promising performance in both efficiency and accuracy. Prior
randomized hashing methods, e.g., Locality-Sensitive Hashing (LSH), explore
data-independent hash functions with random projections or permutations.
Although having elegant theoretic guarantees on the search quality in certain
metric spaces, performance of randomized hashing has been shown insufficient in
many real-world applications. As a remedy, new approaches incorporating
data-driven learning methods in development of advanced hash functions have
emerged. Such learning to hash methods exploit information such as data
distributions or class labels when optimizing the hash codes or functions.
Importantly, the learned hash codes are able to preserve the proximity of
neighboring data in the original feature spaces in the hash code spaces. The
goal of this paper is to provide readers with systematic understanding of
insights, pros and cons of the emerging techniques. We provide a comprehensive
survey of the learning to hash framework and representative techniques of
various types, including unsupervised, semi-supervised, and supervised. In
addition, we also summarize recent hashing approaches utilizing the deep
learning models. Finally, we discuss the future direction and trends of
research in this area
The Pure Leptonic Decays of Meson and Their Radiative Corrections
The radiative corrections to the pure leptonic decay up-to one-loop order is presented. We find the virtual
photon loop corrections to is
negative and the corresponding branching ratio is larger than . Considering the possible experimental resolutions, our prediction of
the radiative decay is not so
large as others, and the best channel to determine the or is
. How to cancel the infrared
divergences appearing in the loop calculations, and the radiative decay
is shown precisely. It is
emphasized that the radiative decay may be separated properly and may compare
with measurements directly as long as the theoretical `softness' of the photon
corresponds to the experimental resolutions.Comment: 11 pages, 1 Latex file, 8 ps figure
Some Variants of Kuniyoshi-Gasch\"utz Theorem with Applications to Noether's Problem
Let be a subgroup of , the symmetric group of degree . For any
field , acts naturally on the rational function field
via -automorphisms defined by for any and . In this
article, we will show that if is a solvable transitive subgroup of
and , then the fixed subfield is
rational (i.e., purely transcendental) over . In proving the above theorem,
we develop some variants of Kuniyoshi-Gasch\"utz Theorem for Noether's problem
Deep Transfer Network: Unsupervised Domain Adaptation
Domain adaptation aims at training a classifier in one dataset and applying
it to a related but not identical dataset. One successfully used framework of
domain adaptation is to learn a transformation to match both the distribution
of the features (marginal distribution), and the distribution of the labels
given features (conditional distribution). In this paper, we propose a new
domain adaptation framework named Deep Transfer Network (DTN), where the highly
flexible deep neural networks are used to implement such a distribution
matching process.
This is achieved by two types of layers in DTN: the shared feature extraction
layers which learn a shared feature subspace in which the marginal
distributions of the source and the target samples are drawn close, and the
discrimination layers which match conditional distributions by classifier
transduction. We also show that DTN has a computation complexity linear to the
number of training samples, making it suitable to large-scale problems. By
combining the best paradigms in both worlds (deep neural networks in
recognition, and matching marginal and conditional distributions in domain
adaptation), we demonstrate by extensive experiments that DTN improves
significantly over former methods in both execution time and classification
accuracy
A classical postselected weak amplification scheme via thermal light cross-Kerr effect
In common sense, postselected weak amplification must be related to
destructive interference effect of the meter system, and a single photon exerts
no effect on thermal field via cross-phasemodulation (XPM) interaction. In this
Letter we present, for the first time, a thermal light cross-Kerr effect.
Through analysis, we reveal two unexpected results: i) postselection and weak
amplification can be explained at a classical level without destructive
interference, and ii) weak amplification and weak value are not one thing.
After postselection a new mixed light can be generated which is nonclassical.
This scheme can be realized via electromagnetically-induced transparency.Comment: Comments are welcome. 6 pages, 11 figure
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