176 research outputs found
Deep Epitomic Convolutional Neural Networks
Deep convolutional neural networks have recently proven extremely competitive
in challenging image recognition tasks. This paper proposes the epitomic
convolution as a new building block for deep neural networks. An epitomic
convolution layer replaces a pair of consecutive convolution and max-pooling
layers found in standard deep convolutional neural networks. The main version
of the proposed model uses mini-epitomes in place of filters and computes
responses invariant to small translations by epitomic search instead of
max-pooling over image positions. The topographic version of the proposed model
uses large epitomes to learn filter maps organized in translational
topographies. We show that error back-propagation can successfully learn
multiple epitomic layers in a supervised fashion. The effectiveness of the
proposed method is assessed in image classification tasks on standard
benchmarks. Our experiments on Imagenet indicate improved recognition
performance compared to standard convolutional neural networks of similar
architecture. Our models pre-trained on Imagenet perform excellently on
Caltech-101. We also obtain competitive image classification results on the
small-image MNIST and CIFAR-10 datasets.Comment: 9 page
Analyzing structural characteristics of object category representations from their semantic-part distributions
Studies from neuroscience show that part-mapping computations are employed by
human visual system in the process of object recognition. In this work, we
present an approach for analyzing semantic-part characteristics of object
category representations. For our experiments, we use category-epitome, a
recently proposed sketch-based spatial representation for objects. To enable
part-importance analysis, we first obtain semantic-part annotations of
hand-drawn sketches originally used to construct the corresponding epitomes. We
then examine the extent to which the semantic-parts are present in the epitomes
of a category and visualize the relative importance of parts as a word cloud.
Finally, we show how such word cloud visualizations provide an intuitive
understanding of category-level structural trends that exist in the
category-epitome object representations
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