44 research outputs found
Collaborative Layer-wise Discriminative Learning in Deep Neural Networks
Intermediate features at different layers of a deep neural network are known
to be discriminative for visual patterns of different complexities. However,
most existing works ignore such cross-layer heterogeneities when classifying
samples of different complexities. For example, if a training sample has
already been correctly classified at a specific layer with high confidence, we
argue that it is unnecessary to enforce rest layers to classify this sample
correctly and a better strategy is to encourage those layers to focus on other
samples.
In this paper, we propose a layer-wise discriminative learning method to
enhance the discriminative capability of a deep network by allowing its layers
to work collaboratively for classification. Towards this target, we introduce
multiple classifiers on top of multiple layers. Each classifier not only tries
to correctly classify the features from its input layer, but also coordinates
with other classifiers to jointly maximize the final classification
performance. Guided by the other companion classifiers, each classifier learns
to concentrate on certain training examples and boosts the overall performance.
Allowing for end-to-end training, our method can be conveniently embedded into
state-of-the-art deep networks. Experiments with multiple popular deep
networks, including Network in Network, GoogLeNet and VGGNet, on scale-various
object classification benchmarks, including CIFAR100, MNIST and ImageNet, and
scene classification benchmarks, including MIT67, SUN397 and Places205,
demonstrate the effectiveness of our method. In addition, we also analyze the
relationship between the proposed method and classical conditional random
fields models.Comment: To appear in ECCV 2016. Maybe subject to minor changes before
camera-ready versio
Deep feature fusion through adaptive discriminative metric learning for scene recognition
With the development of deep learning techniques, fusion of deep features has demonstrated the powerful capability to improve recognition performance. However, most researchers directly fuse different deep feature vectors without considering the complementary and consistent information among them. In this paper, from the viewpoint of metric learning, we propose a novel deep feature fusion method, called deep feature fusion through adaptive discriminative metric learning (DFF-ADML), to explore the complementary and consistent information for scene recognition. Concretely, we formulate an adaptive discriminative metric learning problem, which not only fully exploits discriminative information from each deep feature vector, but also adaptively fuses complementary information from different deep feature vectors. Besides, we map different deep feature vectors of the same image into a common space by different linear transformations, such that the consistent information can be preserved as much as possible. Moreover, DFF-ADML is extended to a kernelized version. Extensive experiments on both natural scene and remote sensing scene datasets demonstrate the superiority and robustness of the proposed deep feature fusion method
Second-order Democratic Aggregation
Aggregated second-order features extracted from deep convolutional networks
have been shown to be effective for texture generation, fine-grained
recognition, material classification, and scene understanding. In this paper,
we study a class of orderless aggregation functions designed to minimize
interference or equalize contributions in the context of second-order features
and we show that they can be computed just as efficiently as their first-order
counterparts and they have favorable properties over aggregation by summation.
Another line of work has shown that matrix power normalization after
aggregation can significantly improve the generalization of second-order
representations. We show that matrix power normalization implicitly equalizes
contributions during aggregation thus establishing a connection between matrix
normalization techniques and prior work on minimizing interference. Based on
the analysis we present {\gamma}-democratic aggregators that interpolate
between sum ({\gamma}=1) and democratic pooling ({\gamma}=0) outperforming both
on several classification tasks. Moreover, unlike power normalization, the
{\gamma}-democratic aggregations can be computed in a low dimensional space by
sketching that allows the use of very high-dimensional second-order features.
This results in a state-of-the-art performance on several datasets
Action Recognition: From Static Datasets to Moving Robots
Deep learning models have achieved state-of-the- art performance in
recognizing human activities, but often rely on utilizing background cues
present in typical computer vision datasets that predominantly have a
stationary camera. If these models are to be employed by autonomous robots in
real world environments, they must be adapted to perform independently of
background cues and camera motion effects. To address these challenges, we
propose a new method that firstly generates generic action region proposals
with good potential to locate one human action in unconstrained videos
regardless of camera motion and then uses action proposals to extract and
classify effective shape and motion features by a ConvNet framework. In a range
of experiments, we demonstrate that by actively proposing action regions during
both training and testing, state-of-the-art or better performance is achieved
on benchmarks. We show the outperformance of our approach compared to the
state-of-the-art in two new datasets; one emphasizes on irrelevant background,
the other highlights the camera motion. We also validate our action recognition
method in an abnormal behavior detection scenario to improve workplace safety.
The results verify a higher success rate for our method due to the ability of
our system to recognize human actions regardless of environment and camera
motion