180 research outputs found
Large-Margin Determinantal Point Processes
Determinantal point processes (DPPs) offer a powerful approach to modeling
diversity in many applications where the goal is to select a diverse subset. We
study the problem of learning the parameters (the kernel matrix) of a DPP from
labeled training data. We make two contributions. First, we show how to
reparameterize a DPP's kernel matrix with multiple kernel functions, thus
enhancing modeling flexibility. Second, we propose a novel parameter estimation
technique based on the principle of large margin separation. In contrast to the
state-of-the-art method of maximum likelihood estimation, our large-margin loss
function explicitly models errors in selecting the target subsets, and it can
be customized to trade off different types of errors (precision vs. recall).
Extensive empirical studies validate our contributions, including applications
on challenging document and video summarization, where flexibility in modeling
the kernel matrix and balancing different errors is indispensable.Comment: 15 page
Learning Detection with Diverse Proposals
To predict a set of diverse and informative proposals with enriched
representations, this paper introduces a differentiable Determinantal Point
Process (DPP) layer that is able to augment the object detection architectures.
Most modern object detection architectures, such as Faster R-CNN, learn to
localize objects by minimizing deviations from the ground-truth but ignore
correlation between multiple proposals and object categories. Non-Maximum
Suppression (NMS) as a widely used proposal pruning scheme ignores label- and
instance-level relations between object candidates resulting in multi-labeled
detections. In the multi-class case, NMS selects boxes with the largest
prediction scores ignoring the semantic relation between categories of
potential election. In contrast, our trainable DPP layer, allowing for Learning
Detection with Diverse Proposals (LDDP), considers both label-level contextual
information and spatial layout relationships between proposals without
increasing the number of parameters of the network, and thus improves location
and category specifications of final detected bounding boxes substantially
during both training and inference schemes. Furthermore, we show that LDDP
keeps it superiority over Faster R-CNN even if the number of proposals
generated by LDPP is only ~30% as many as those for Faster R-CNN.Comment: Accepted to CVPR 201
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