Book Image

Natural Language Processing with TensorFlow

By : Motaz Saad, Thushan Ganegedara
Book Image

Natural Language Processing with TensorFlow

By: Motaz Saad, Thushan Ganegedara

Overview of this book

Natural language processing (NLP) supplies the majority of data available to deep learning applications, while TensorFlow is the most important deep learning framework currently available. Natural Language Processing with TensorFlow brings TensorFlow and NLP together to give you invaluable tools to work with the immense volume of unstructured data in today’s data streams, and apply these tools to specific NLP tasks. Thushan Ganegedara starts by giving you a grounding in NLP and TensorFlow basics. You'll then learn how to use Word2vec, including advanced extensions, to create word embeddings that turn sequences of words into vectors accessible to deep learning algorithms. Chapters on classical deep learning algorithms, like convolutional neural networks (CNN) and recurrent neural networks (RNN), demonstrate important NLP tasks as sentence classification and language generation. You will learn how to apply high-performance RNN models, like long short-term memory (LSTM) cells, to NLP tasks. You will also explore neural machine translation and implement a neural machine translator. After reading this book, you will gain an understanding of NLP and you'll have the skills to apply TensorFlow in deep learning NLP applications, and how to perform specific NLP tasks.
Table of Contents (16 chapters)
Natural Language Processing with TensorFlow
Contributors
Preface
Index

Preparing captions for feeding into LSTMs


Now, before feeding word vectors along with image feature vectors, we need to perform a few more preprocessing steps on the caption data.

Before the preprocessing, let's look at a few basic statistics about the captions. A caption has approximately ten words on average, with a standard deviation of approximately two words. This information is important for us to truncate captions which are unnecessarily long.

First, following the preceding statistics, let's set the maximum caption length allowed to be 12.

Next, let's introduce two new word tokens, SOS and EOS. SOS denotes the start of a sentence, whereas EOS denotes the end of a sentence. These help the LSTM to identify both the start and end of a sentence easily.

Next, we will append captions with length less than 12 with EOS tokens such that their length is 12.

So, consider the following caption:

a man standing on a tennis court holding a racquet

This would appear as follows:

SOS a man standing on a...