2,664 research outputs found
Applying Data Augmentation to Handwritten Arabic Numeral Recognition Using Deep Learning Neural Networks
Handwritten character recognition has been the center of research and a
benchmark problem in the sector of pattern recognition and artificial
intelligence, and it continues to be a challenging research topic. Due to its
enormous application many works have been done in this field focusing on
different languages. Arabic, being a diversified language has a huge scope of
research with potential challenges. A convolutional neural network model for
recognizing handwritten numerals in Arabic language is proposed in this paper,
where the dataset is subject to various augmentation in order to add robustness
needed for deep learning approach. The proposed method is empowered by the
presence of dropout regularization to do away with the problem of data
overfitting. Moreover, suitable change is introduced in activation function to
overcome the problem of vanishing gradient. With these modifications, the
proposed system achieves an accuracy of 99.4\% which performs better than every
previous work on the dataset.Comment: 5 pages, 6 figures, 3 table
Unsupervised Adaptation for Synthetic-to-Real Handwritten Word Recognition
Handwritten Text Recognition (HTR) is still a challenging problem because it
must deal with two important difficulties: the variability among writing
styles, and the scarcity of labelled data. To alleviate such problems,
synthetic data generation and data augmentation are typically used to train HTR
systems. However, training with such data produces encouraging but still
inaccurate transcriptions in real words. In this paper, we propose an
unsupervised writer adaptation approach that is able to automatically adjust a
generic handwritten word recognizer, fully trained with synthetic fonts,
towards a new incoming writer. We have experimentally validated our proposal
using five different datasets, covering several challenges (i) the document
source: modern and historic samples, which may involve paper degradation
problems; (ii) different handwriting styles: single and multiple writer
collections; and (iii) language, which involves different character
combinations. Across these challenging collections, we show that our system is
able to maintain its performance, thus, it provides a practical and generic
approach to deal with new document collections without requiring any expensive
and tedious manual annotation step.Comment: Accepted to WACV 202
TextCaps : Handwritten Character Recognition with Very Small Datasets
Many localized languages struggle to reap the benefits of recent advancements
in character recognition systems due to the lack of substantial amount of
labeled training data. This is due to the difficulty in generating large
amounts of labeled data for such languages and inability of deep learning
techniques to properly learn from small number of training samples. We solve
this problem by introducing a technique of generating new training samples from
the existing samples, with realistic augmentations which reflect actual
variations that are present in human hand writing, by adding random controlled
noise to their corresponding instantiation parameters. Our results with a mere
200 training samples per class surpass existing character recognition results
in the EMNIST-letter dataset while achieving the existing results in the three
datasets: EMNIST-balanced, EMNIST-digits, and MNIST. We also develop a strategy
to effectively use a combination of loss functions to improve reconstructions.
Our system is useful in character recognition for localized languages that lack
much labeled training data and even in other related more general contexts such
as object recognition
Boosting Handwriting Text Recognition in Small Databases with Transfer Learning
In this paper we deal with the offline handwriting text recognition (HTR)
problem with reduced training datasets. Recent HTR solutions based on
artificial neural networks exhibit remarkable solutions in referenced
databases. These deep learning neural networks are composed of both
convolutional (CNN) and long short-term memory recurrent units (LSTM). In
addition, connectionist temporal classification (CTC) is the key to avoid
segmentation at character level, greatly facilitating the labeling task. One of
the main drawbacks of the CNNLSTM-CTC (CLC) solutions is that they need a
considerable part of the text to be transcribed for every type of calligraphy,
typically in the order of a few thousands of lines. Furthermore, in some
scenarios the text to transcribe is not that long, e.g. in the Washington
database. The CLC typically overfits for this reduced number of training
samples. Our proposal is based on the transfer learning (TL) from the
parameters learned with a bigger database. We first investigate, for a reduced
and fixed number of training samples, 350 lines, how the learning from a large
database, the IAM, can be transferred to the learning of the CLC of a reduced
database, Washington. We focus on which layers of the network could be not
re-trained. We conclude that the best solution is to re-train the whole CLC
parameters initialized to the values obtained after the training of the CLC
from the larger database. We also investigate results when the training size is
further reduced. The differences in the CER are more remarkable when training
with just 350 lines, a CER of 3.3% is achieved with TL while we have a CER of
18.2% when training from scratch. As a byproduct, the learning times are quite
reduced. Similar good results are obtained from the Parzival database when
trained with this reduced number of lines and this new approach.Comment: ICFHR 2018 Conferenc
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