Book Image

Hands-On Vision and Behavior for Self-Driving Cars

By : Luca Venturi, Krishtof Korda
Book Image

Hands-On Vision and Behavior for Self-Driving Cars

By: Luca Venturi, Krishtof Korda

Overview of this book

The visual perception capabilities of a self-driving car are powered by computer vision. The work relating to self-driving cars can be broadly classified into three components - robotics, computer vision, and machine learning. This book provides existing computer vision engineers and developers with the unique opportunity to be associated with this booming field. You will learn about computer vision, deep learning, and depth perception applied to driverless cars. The book provides a structured and thorough introduction, as making a real self-driving car is a huge cross-functional effort. As you progress, you will cover relevant cases with working code, before going on to understand how to use OpenCV, TensorFlow and Keras to analyze video streaming from car cameras. Later, you will learn how to interpret and make the most of lidars (light detection and ranging) to identify obstacles and localize your position. You’ll even be able to tackle core challenges in self-driving cars such as finding lanes, detecting pedestrian and crossing lights, performing semantic segmentation, and writing a PID controller. By the end of this book, you’ll be equipped with the skills you need to write code for a self-driving car running in a driverless car simulator, and be able to tackle various challenges faced by autonomous car engineers.
Table of Contents (17 chapters)
1
Section 1: OpenCV and Sensors and Signals
5
Section 2: Improving How the Self-Driving Car Works with Deep Learning and Neural Networks
12
Section 3: Mapping and Controls

Understanding classifiers

Deep learning can be used for many different tasks. For what concerns images and CNN, a very common task is classification. Given an image, the neural network needs to classify it, using one of the labels provided during training. Not surprisingly, a network of this type is called a classifier.

To do so, the neural network will have one output for each label (for example, on the 10 digits MNIST dataset, we have 10 labels and so 10 outputs) and only one output should be 1, while all the other outputs should be 0.

How will a neural network achieve this state? Well, it doesn't. The neural network produces floating point outputs as a result of the internal multiplications and sums, and very seldom you get a similar output. However, we can consider the highest value as the hot one (1), and all the others can be considered cold (0).

We usually apply a softmax layer at the end of the neural network, which converts the outputs in to probability, meaning...