11 research outputs found
Panoramic Panoptic Segmentation: Insights Into Surrounding Parsing for Mobile Agents via Unsupervised Contrastive Learning
In this work, we introduce panoramic panoptic segmentation, as the most
holistic scene understanding, both in terms of Field of View (FoV) and
image-level understanding for standard camera-based input. A complete
surrounding understanding provides a maximum of information to a mobile agent.
This is essential information for any intelligent vehicle to make informed
decisions in a safety-critical dynamic environment such as real-world traffic.
In order to overcome the lack of annotated panoramic images, we propose a
framework which allows model training on standard pinhole images and transfers
the learned features to the panoramic domain in a cost-minimizing way. The
domain shift from pinhole to panoramic images is non-trivial as large objects
and surfaces are heavily distorted close to the image border regions and look
different across the two domains. Using our proposed method with dense
contrastive learning, we manage to achieve significant improvements over a
non-adapted approach. Depending on the efficient panoptic segmentation
architecture, we can improve 3.5-6.5% measured in Panoptic Quality (PQ) over
non-adapted models on our established Wild Panoramic Panoptic Segmentation
(WildPPS) dataset. Furthermore, our efficient framework does not need access to
the images of the target domain, making it a feasible domain generalization
approach suitable for a limited hardware setting. As additional contributions,
we publish WildPPS: The first panoramic panoptic image dataset to foster
progress in surrounding perception and explore a novel training procedure
combining supervised and contrastive training.Comment: Accepted to IEEE Transactions on Intelligent Transportation Systems
(T-ITS). Extended version of arXiv:2103.00868. The project is at
https://github.com/alexanderjaus/PP
Heavy to Light Meson Exclusive Semileptonic Decays in Effective Field Theory of Heavy Quark
We present a general study on exclusive semileptonic decays of heavy (B, D,
B_s) to light (pi, rho, K, K^*) mesons in the framework of effective field
theory of heavy quark. Transition matrix elements of these decays can be
systematically characterized by a set of wave functions which are independent
of the heavy quark mass except for the implicit scale dependence. Form factors
for all these decays are calculated consistently within the effective theory
framework using the light cone sum rule method at the leading order of 1/m_Q
expansion. The branching ratios of these decays are evaluated, and the heavy
and light flavor symmetry breaking effects are investigated. We also give
comparison of our results and the predictions from other approaches, among
which are the relations proposed recently in the framework of large energy
effective theory.Comment: 18 pages, ReVtex, 5 figures, added references and comparison of
results, and corrected signs in some formula
Use and Misuse of QCD Sum Rules in Heavy-to-light Transitions: the Decay Reexamined
The existing calculations of the form factors describing the decay from QCD sum rules have yielded conflicting results at small values of
the invariant mass squared of the lepton pair. We demonstrate that the
disagreement originates from the failure of the short-distance expansion to
describe the meson distribution amplitude in the region where almost the
whole momentum is carried by one of the constituents. This limits the
applicability of QCD sum rules based on the short-distance expansion of a
three-point correlation function to heavy-to-light transitions and calls for an
expansion around the light-cone, as realized in the light-cone sum rule
approach. We derive and update light-cone sum rules for all the semileptonic
form factors, using recent results on the meson distribution amplitudes.
The results are presented in detail together with a careful analysis of the
uncertainties, including estimates of higher-twist effects, and compared to
lattice calculations and recent CLEO measurements. We also derive a set of
``improved'' three-point sum rules, in which some of the problems of the
short-distance expansion are avoided and whose results agree to good accuracy
with those from light-cone sum rules.Comment: 34 pages Latex; two references added; one typo in one table
corrected; accepted for publication in Phys. Rev.
PROSPECTS FOR B-PHYSICS IN THE NEXT DECADE
In these lectures I review what has been learned from studies of b-quark decays, including semileptonic decays (Vub and Vcb), B o −B o mixing and rare B decays. Then a discussion on CP violation follows, which leads to a summary of plans for future experiments and what is expected to be learned from them
MedShapeNet -- A Large-Scale Dataset of 3D Medical Shapes for Computer Vision
16 pagesPrior to the deep learning era, shape was commonly used to describe the objects. Nowadays, state-of-the-art (SOTA) algorithms in medical imaging are predominantly diverging from computer vision, where voxel grids, meshes, point clouds, and implicit surface models are used. This is seen from numerous shape-related publications in premier vision conferences as well as the growing popularity of ShapeNet (about 51,300 models) and Princeton ModelNet (127,915 models). For the medical domain, we present a large collection of anatomical shapes (e.g., bones, organs, vessels) and 3D models of surgical instrument, called MedShapeNet, created to facilitate the translation of data-driven vision algorithms to medical applications and to adapt SOTA vision algorithms to medical problems. As a unique feature, we directly model the majority of shapes on the imaging data of real patients. As of today, MedShapeNet includes 23 dataset with more than 100,000 shapes that are paired with annotations (ground truth). Our data is freely accessible via a web interface and a Python application programming interface (API) and can be used for discriminative, reconstructive, and variational benchmarks as well as various applications in virtual, augmented, or mixed reality, and 3D printing. Exemplary, we present use cases in the fields of classification of brain tumors, facial and skull reconstructions, multi-class anatomy completion, education, and 3D printing. In future, we will extend the data and improve the interfaces. The project pages are: https://medshapenet.ikim.nrw/ and https://github.com/Jianningli/medshapenet-feedbac
MedShapeNet -- A Large-Scale Dataset of 3D Medical Shapes for Computer Vision
16 pagesPrior to the deep learning era, shape was commonly used to describe the objects. Nowadays, state-of-the-art (SOTA) algorithms in medical imaging are predominantly diverging from computer vision, where voxel grids, meshes, point clouds, and implicit surface models are used. This is seen from numerous shape-related publications in premier vision conferences as well as the growing popularity of ShapeNet (about 51,300 models) and Princeton ModelNet (127,915 models). For the medical domain, we present a large collection of anatomical shapes (e.g., bones, organs, vessels) and 3D models of surgical instrument, called MedShapeNet, created to facilitate the translation of data-driven vision algorithms to medical applications and to adapt SOTA vision algorithms to medical problems. As a unique feature, we directly model the majority of shapes on the imaging data of real patients. As of today, MedShapeNet includes 23 dataset with more than 100,000 shapes that are paired with annotations (ground truth). Our data is freely accessible via a web interface and a Python application programming interface (API) and can be used for discriminative, reconstructive, and variational benchmarks as well as various applications in virtual, augmented, or mixed reality, and 3D printing. Exemplary, we present use cases in the fields of classification of brain tumors, facial and skull reconstructions, multi-class anatomy completion, education, and 3D printing. In future, we will extend the data and improve the interfaces. The project pages are: https://medshapenet.ikim.nrw/ and https://github.com/Jianningli/medshapenet-feedbac