161 research outputs found
Elliptic Genus Derivation of 4d Holomorphic Blocks
We study elliptic vortices on by considering the 2d
quiver gauge theory describing their moduli spaces. The elliptic genus of these
moduli spaces is the elliptic version of vortex partition function of the 4d
theory. We focus on two examples: the first is a ,
gauge theory with fundamental and anti-fundamental matter; the
second is a , gauge theory with matter in the
fundamental representation. The results are instances of 4d "holomorphic
blocks" into which partition functions on more complicated surfaces factorize.
They can also be interpreted as free-field representations of elliptic Virasoro
algebrae.Comment: 15 pages, 2 figure
Guided Stereo Matching
Stereo is a prominent technique to infer dense depth maps from images, and
deep learning further pushed forward the state-of-the-art, making end-to-end
architectures unrivaled when enough data is available for training. However,
deep networks suffer from significant drops in accuracy when dealing with new
environments. Therefore, in this paper, we introduce Guided Stereo Matching, a
novel paradigm leveraging a small amount of sparse, yet reliable depth
measurements retrieved from an external source enabling to ameliorate this
weakness. The additional sparse cues required by our method can be obtained
with any strategy (e.g., a LiDAR) and used to enhance features linked to
corresponding disparity hypotheses. Our formulation is general and fully
differentiable, thus enabling to exploit the additional sparse inputs in
pre-trained deep stereo networks as well as for training a new instance from
scratch. Extensive experiments on three standard datasets and two
state-of-the-art deep architectures show that even with a small set of sparse
input cues, i) the proposed paradigm enables significant improvements to
pre-trained networks. Moreover, ii) training from scratch notably increases
accuracy and robustness to domain shifts. Finally, iii) it is suited and
effective even with traditional stereo algorithms such as SGM.Comment: CVPR 201
Perturbative evaluation of circular 1/2 BPS Wilson loops in N = 6 Super Chern-Simons theories
We present a complete two-loop analysis of the quantum expectation value for
circular BPS Wilson loops in ABJ(M) theories. We examine in details the 1/2 BPS
case, that requires non-trivial fermionic couplings with the contour, finding
perfect agreement with the exact matrix model answer at zero framing. The
result is obtained through a careful application of DRED regularization scheme,
combined with a judicious rearrangement of the relevant perturbative
contributions that reduces the computation to simple integrals. We carefully
analyze the contribution of fermions that is crucial for the consistency with
the localization procedure and point out the arising of pivotal evanescent
terms, discussing their meaning in relation to Ward identities.Comment: 32 pages, 5 figures, Referemces adde
Real-time self-adaptive deep stereo
Deep convolutional neural networks trained end-to-end are the
state-of-the-art methods to regress dense disparity maps from stereo pairs.
These models, however, suffer from a notable decrease in accuracy when exposed
to scenarios significantly different from the training set, e.g., real vs
synthetic images, etc.). We argue that it is extremely unlikely to gather
enough samples to achieve effective training/tuning in any target domain, thus
making this setup impractical for many applications. Instead, we propose to
perform unsupervised and continuous online adaptation of a deep stereo network,
which allows for preserving its accuracy in any environment. However, this
strategy is extremely computationally demanding and thus prevents real-time
inference. We address this issue introducing a new lightweight, yet effective,
deep stereo architecture, Modularly ADaptive Network (MADNet) and developing a
Modular ADaptation (MAD) algorithm, which independently trains sub-portions of
the network. By deploying MADNet together with MAD we introduce the first
real-time self-adaptive deep stereo system enabling competitive performance on
heterogeneous datasets.Comment: Accepted at CVPR2019 as oral presentation. Code Available
https://github.com/CVLAB-Unibo/Real-time-self-adaptive-deep-stere
Computer vision for 3d perception and applications
Effective 3D perception of an observed scene greatly enriches the knowledge about the surrounding environment and is crucial to effectively develop high-level applications for various purposes [...
TemporalStereo: Efficient Spatial-Temporal Stereo Matching Network
We present TemporalStereo, a coarse-to-fine based online stereo matching
network which is highly efficient, and able to effectively exploit the past
geometry and context information to boost the matching accuracy. Our network
leverages sparse cost volume and proves to be effective when a single stereo
pair is given, however, its peculiar ability to use spatio-temporal information
across frames allows TemporalStereo to alleviate problems such as occlusions
and reflective regions while enjoying high efficiency also in the case of
stereo sequences. Notably our model trained, once with stereo videos, can run
in both single-pair and temporal ways seamlessly. Experiments show that our
network relying on camera motion is even robust to dynamic objects when running
on videos. We validate TemporalStereo through extensive experiments on
synthetic (SceneFlow, TartanAir) and real (KITTI 2012, KITTI 2015) datasets.
Detailed results show that our model achieves state-of-the-art performance on
any of these datasets. Code is available at
\url{https://github.com/youmi-zym/TemporalStereo.git}
- …