Book Image

Hands-On Deep Learning Algorithms with Python

By : Sudharsan Ravichandiran
Book Image

Hands-On Deep Learning Algorithms with Python

By: Sudharsan Ravichandiran

Overview of this book

Deep learning is one of the most popular domains in the AI space that allows you to develop multi-layered models of varying complexities. This book introduces you to popular deep learning algorithms—from basic to advanced—and shows you how to implement them from scratch using TensorFlow. Throughout the book, you will gain insights into each algorithm, the mathematical principles involved, and how to implement it in the best possible manner. The book starts by explaining how you can build your own neural networks, followed by introducing you to TensorFlow, the powerful Python-based library for machine learning and deep learning. Moving on, you will get up to speed with gradient descent variants, such as NAG, AMSGrad, AdaDelta, Adam, and Nadam. The book will then provide you with insights into recurrent neural networks (RNNs) and LSTM and how to generate song lyrics with RNN. Next, you will master the math necessary to work with convolutional and capsule networks, widely used for image recognition tasks. You will also learn how machines understand the semantics of words and documents using CBOW, skip-gram, and PV-DM. Finally, you will explore GANs, including InfoGAN and LSGAN, and autoencoders, such as contractive autoencoders and VAE. By the end of this book, you will be equipped with all the skills you need to implement deep learning in your own projects.
Table of Contents (17 chapters)
Free Chapter
1
Section 1: Getting Started with Deep Learning
4
Section 2: Fundamental Deep Learning Algorithms
10
Section 3: Advanced Deep Learning Algorithms

Least squares GAN

We just learned how GANs are used to generate images. Least Squares GAN (LSGAN) is another simple variant of a GAN. As the name suggests, here, we use the least square error as a loss function instead of sigmoid cross-entropy loss. With LSGAN, we can improve the quality of images being generated from the GAN. But how can we do that? Why do the vanilla GANs generate poor quality images?

If you can recollect the loss function of GAN, we used sigmoid cross-entropy as the loss function. The goal of the generator is to learn the distribution of the images in the training set, that is, real data distribution, map it to the fake distribution, and generate fake samples from the learned fake distribution. So, the GANs try to map the fake distribution as close to the true distribution as possible.

But once the fake samples are on the correct side of the decision surface...