2,991 research outputs found
Proposal Flow
Finding image correspondences remains a challenging problem in the presence
of intra-class variations and large changes in scene layout.~Semantic flow
methods are designed to handle images depicting different instances of the same
object or scene category. We introduce a novel approach to semantic flow,
dubbed proposal flow, that establishes reliable correspondences using object
proposals. Unlike prevailing semantic flow approaches that operate on pixels or
regularly sampled local regions, proposal flow benefits from the
characteristics of modern object proposals, that exhibit high repeatability at
multiple scales, and can take advantage of both local and geometric consistency
constraints among proposals. We also show that proposal flow can effectively be
transformed into a conventional dense flow field. We introduce a new dataset
that can be used to evaluate both general semantic flow techniques and
region-based approaches such as proposal flow. We use this benchmark to compare
different matching algorithms, object proposals, and region features within
proposal flow, to the state of the art in semantic flow. This comparison, along
with experiments on standard datasets, demonstrates that proposal flow
significantly outperforms existing semantic flow methods in various settings
Learning and Matching Multi-View Descriptors for Registration of Point Clouds
Critical to the registration of point clouds is the establishment of a set of
accurate correspondences between points in 3D space. The correspondence problem
is generally addressed by the design of discriminative 3D local descriptors on
the one hand, and the development of robust matching strategies on the other
hand. In this work, we first propose a multi-view local descriptor, which is
learned from the images of multiple views, for the description of 3D keypoints.
Then, we develop a robust matching approach, aiming at rejecting outlier
matches based on the efficient inference via belief propagation on the defined
graphical model. We have demonstrated the boost of our approaches to
registration on the public scanning and multi-view stereo datasets. The
superior performance has been verified by the intensive comparisons against a
variety of descriptors and matching methods
Proposal Flow: Semantic Correspondences from Object Proposals
Finding image correspondences remains a challenging problem in the presence
of intra-class variations and large changes in scene layout. Semantic flow
methods are designed to handle images depicting different instances of the same
object or scene category. We introduce a novel approach to semantic flow,
dubbed proposal flow, that establishes reliable correspondences using object
proposals. Unlike prevailing semantic flow approaches that operate on pixels or
regularly sampled local regions, proposal flow benefits from the
characteristics of modern object proposals, that exhibit high repeatability at
multiple scales, and can take advantage of both local and geometric consistency
constraints among proposals. We also show that the corresponding sparse
proposal flow can effectively be transformed into a conventional dense flow
field. We introduce two new challenging datasets that can be used to evaluate
both general semantic flow techniques and region-based approaches such as
proposal flow. We use these benchmarks to compare different matching
algorithms, object proposals, and region features within proposal flow, to the
state of the art in semantic flow. This comparison, along with experiments on
standard datasets, demonstrates that proposal flow significantly outperforms
existing semantic flow methods in various settings.Comment: arXiv admin note: text overlap with arXiv:1511.0506
HDMNet: A Hierarchical Matching Network with Double Attention for Large-scale Outdoor LiDAR Point Cloud Registration
Outdoor LiDAR point clouds are typically large-scale and complexly
distributed. To achieve efficient and accurate registration, emphasizing the
similarity among local regions and prioritizing global local-to-local matching
is of utmost importance, subsequent to which accuracy can be enhanced through
cost-effective fine registration. In this paper, a novel hierarchical neural
network with double attention named HDMNet is proposed for large-scale outdoor
LiDAR point cloud registration. Specifically, A novel feature consistency
enhanced double-soft matching network is introduced to achieve two-stage
matching with high flexibility while enlarging the receptive field with high
efficiency in a patch-to patch manner, which significantly improves the
registration performance. Moreover, in order to further utilize the sparse
matching information from deeper layer, we develop a novel trainable embedding
mask to incorporate the confidence scores of correspondences obtained from pose
estimation of deeper layer, eliminating additional computations. The
high-confidence keypoints in the sparser point cloud of the deeper layer
correspond to a high-confidence spatial neighborhood region in shallower layer,
which will receive more attention, while the features of non-key regions will
be masked. Extensive experiments are conducted on two large-scale outdoor LiDAR
point cloud datasets to demonstrate the high accuracy and efficiency of the
proposed HDMNet.Comment: Accepted by WACV202
ResMatch: Residual Attention Learning for Local Feature Matching
Attention-based graph neural networks have made great progress in feature
matching learning. However, insight of how attention mechanism works for
feature matching is lacked in the literature. In this paper, we rethink cross-
and self-attention from the viewpoint of traditional feature matching and
filtering. In order to facilitate the learning of matching and filtering, we
inject the similarity of descriptors and relative positions into cross- and
self-attention score, respectively. In this way, the attention can focus on
learning residual matching and filtering functions with reference to the basic
functions of measuring visual and spatial correlation. Moreover, we mine intra-
and inter-neighbors according to the similarity of descriptors and relative
positions. Then sparse attention for each point can be performed only within
its neighborhoods to acquire higher computation efficiency. Feature matching
networks equipped with our full and sparse residual attention learning
strategies are termed ResMatch and sResMatch respectively. Extensive
experiments, including feature matching, pose estimation and visual
localization, confirm the superiority of our networks
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