Book Image

Neural Networks with Keras Cookbook

By : V Kishore Ayyadevara
Book Image

Neural Networks with Keras Cookbook

By: V Kishore Ayyadevara

Overview of this book

This book will take you from the basics of neural networks to advanced implementations of architectures using a recipe-based approach. We will learn about how neural networks work and the impact of various hyper parameters on a network's accuracy along with leveraging neural networks for structured and unstructured data. Later, we will learn how to classify and detect objects in images. We will also learn to use transfer learning for multiple applications, including a self-driving car using Convolutional Neural Networks. We will generate images while leveraging GANs and also by performing image encoding. Additionally, we will perform text analysis using word vector based techniques. Later, we will use Recurrent Neural Networks and LSTM to implement chatbot and Machine Translation systems. Finally, you will learn about transcribing images, audio, and generating captions and also use Deep Q-learning to build an agent that plays Space Invaders game. By the end of this book, you will have developed the skills to choose and customize multiple neural network architectures for various deep learning problems you might encounter.
Table of Contents (18 chapters)

Calculating an intersection over a union between two images

To understand how accurate the proposed regions are, we use a metric named Intersection over Union (IoU). IoU can be visualized as follows:

Note that, in the preceding picture, the blue box (lower one) is the ground truth and the red box (the upper rectangle) is the region proposal.

The intersection over the union of the region proposal is calculated as the ratio of the intersection of the proposal and the ground truth over the union of the region proposal and the ground truth.

How to do it...

IoU is calculated as follows (the code file is available as Selective_search.ipynb in GitHub):

  1. Define the IoU extraction function, demonstrated in the following code:
from...