2,384 research outputs found
Convolutional Neural Networks Applied to House Numbers Digit Classification
We classify digits of real-world house numbers using convolutional neural
networks (ConvNets). ConvNets are hierarchical feature learning neural networks
whose structure is biologically inspired. Unlike many popular vision approaches
that are hand-designed, ConvNets can automatically learn a unique set of
features optimized for a given task. We augmented the traditional ConvNet
architecture by learning multi-stage features and by using Lp pooling and
establish a new state-of-the-art of 94.85% accuracy on the SVHN dataset (45.2%
error improvement). Furthermore, we analyze the benefits of different pooling
methods and multi-stage features in ConvNets. The source code and a tutorial
are available at eblearn.sf.net.Comment: 4 pages, 6 figures, 2 table
Multi-digit Number Recognition from Street View Imagery using Deep Convolutional Neural Networks
Recognizing arbitrary multi-character text in unconstrained natural
photographs is a hard problem. In this paper, we address an equally hard
sub-problem in this domain viz. recognizing arbitrary multi-digit numbers from
Street View imagery. Traditional approaches to solve this problem typically
separate out the localization, segmentation, and recognition steps. In this
paper we propose a unified approach that integrates these three steps via the
use of a deep convolutional neural network that operates directly on the image
pixels. We employ the DistBelief implementation of deep neural networks in
order to train large, distributed neural networks on high quality images. We
find that the performance of this approach increases with the depth of the
convolutional network, with the best performance occurring in the deepest
architecture we trained, with eleven hidden layers. We evaluate this approach
on the publicly available SVHN dataset and achieve over accuracy in
recognizing complete street numbers. We show that on a per-digit recognition
task, we improve upon the state-of-the-art, achieving accuracy. We
also evaluate this approach on an even more challenging dataset generated from
Street View imagery containing several tens of millions of street number
annotations and achieve over accuracy. To further explore the
applicability of the proposed system to broader text recognition tasks, we
apply it to synthetic distorted text from reCAPTCHA. reCAPTCHA is one of the
most secure reverse turing tests that uses distorted text to distinguish humans
from bots. We report a accuracy on the hardest category of reCAPTCHA.
Our evaluations on both tasks indicate that at specific operating thresholds,
the performance of the proposed system is comparable to, and in some cases
exceeds, that of human operators
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