58 research outputs found
Unsupervised Domain Adaptation for 3D Keypoint Estimation via View Consistency
In this paper, we introduce a novel unsupervised domain adaptation technique
for the task of 3D keypoint prediction from a single depth scan or image. Our
key idea is to utilize the fact that predictions from different views of the
same or similar objects should be consistent with each other. Such view
consistency can provide effective regularization for keypoint prediction on
unlabeled instances. In addition, we introduce a geometric alignment term to
regularize predictions in the target domain. The resulting loss function can be
effectively optimized via alternating minimization. We demonstrate the
effectiveness of our approach on real datasets and present experimental results
showing that our approach is superior to state-of-the-art general-purpose
domain adaptation techniques.Comment: ECCV 201
Deep learning with 3D and label geometry
A fine-grained understanding of an image is two-fold: visual understanding and semantic understanding. The former strives to understand the intrinsic properties of the object in the image, whereas the latter aims at associating the diverse objects with certain semantics. All of these form the basis of an in-depth understanding of images. Today’s default architectures of deep convolutional networks have already shown a remarkable ability in capturing the 2D visual appearances of images, and mapping visual content to semantic classes thereafter. However, research on fine-grained image understanding, such as inferring the intrinsic 3D information and more structured semantics, is less explored. In this thesis, we look at the problems by asking "How to better utilize geometry for better image understanding?" In the first part, we research visual image understanding with 3D geometry. We show that it is possible to automatically explain a variety of visual contents in the image with texture-free 3D shapes. Furthermore, we develop a deep learning framework to reliably recover a set of 3D geometric attributes, such as the pose of an object and the surface normal of its shape, from a 2D image. In the second part, we explore label geometry for semantic image understanding. We find that a set of image classification problems have geometrically similar probability spaces. Therefore, label geometry is introduced, unifying one-vs.-rest classification, multi-label classification, and out-of-distribution classification in one framework. Moreover, we show that learned hierarchical label geometries can balance the accuracy and specificity of an image classifier
A survey on deep geometry learning: from a representation perspective
Researchers have achieved great success in dealing with 2D images using deep learning. In recent years, 3D computer vision and geometry deep learning have gained ever more attention. Many advanced techniques for 3D shapes have been proposed for different applications. Unlike 2D images, which can be uniformly represented by a regular grid of pixels, 3D shapes have various representations, such as depth images, multi-view images, voxels, point clouds, meshes, implicit surfaces, etc. The performance achieved in different applications largely depends on the representation used, and there is no unique representation that works well for all applications. Therefore, in this survey, we review recent developments in deep learning for 3D geometry from a representation perspective, summarizing the advantages and disadvantages of different representations for different applications. We also present existing datasets in these representations and further discuss future research directions
Challenges for Monocular 6D Object Pose Estimation in Robotics
Object pose estimation is a core perception task that enables, for example,
object grasping and scene understanding. The widely available, inexpensive and
high-resolution RGB sensors and CNNs that allow for fast inference based on
this modality make monocular approaches especially well suited for robotics
applications. We observe that previous surveys on object pose estimation
establish the state of the art for varying modalities, single- and multi-view
settings, and datasets and metrics that consider a multitude of applications.
We argue, however, that those works' broad scope hinders the identification of
open challenges that are specific to monocular approaches and the derivation of
promising future challenges for their application in robotics. By providing a
unified view on recent publications from both robotics and computer vision, we
find that occlusion handling, novel pose representations, and formalizing and
improving category-level pose estimation are still fundamental challenges that
are highly relevant for robotics. Moreover, to further improve robotic
performance, large object sets, novel objects, refractive materials, and
uncertainty estimates are central, largely unsolved open challenges. In order
to address them, ontological reasoning, deformability handling, scene-level
reasoning, realistic datasets, and the ecological footprint of algorithms need
to be improved.Comment: arXiv admin note: substantial text overlap with arXiv:2302.1182
Multi-Modal 3D Object Detection in Autonomous Driving: a Survey
In the past few years, we have witnessed rapid development of autonomous
driving. However, achieving full autonomy remains a daunting task due to the
complex and dynamic driving environment. As a result, self-driving cars are
equipped with a suite of sensors to conduct robust and accurate environment
perception. As the number and type of sensors keep increasing, combining them
for better perception is becoming a natural trend. So far, there has been no
indepth review that focuses on multi-sensor fusion based perception. To bridge
this gap and motivate future research, this survey devotes to review recent
fusion-based 3D detection deep learning models that leverage multiple sensor
data sources, especially cameras and LiDARs. In this survey, we first introduce
the background of popular sensors for autonomous cars, including their common
data representations as well as object detection networks developed for each
type of sensor data. Next, we discuss some popular datasets for multi-modal 3D
object detection, with a special focus on the sensor data included in each
dataset. Then we present in-depth reviews of recent multi-modal 3D detection
networks by considering the following three aspects of the fusion: fusion
location, fusion data representation, and fusion granularity. After a detailed
review, we discuss open challenges and point out possible solutions. We hope
that our detailed review can help researchers to embark investigations in the
area of multi-modal 3D object detection
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